varicella vaccine near me :: Article CreatorLIVE ATTENUATED VARICELLA VACCINE: USE IN HEALTHY ADULTS
We administered live attenuated varicella vaccine to 187 healthy adults seronegative to varicella-zoster virus (VZV); 176 have been followed at least 2 mos. 121/176 (69%) received 2 doses about 3 months apart. Side effects after 1 dose were: local reactions in 18 (10%), rash in 12 (7%), & fever in 4(2%). Side effects were less frequent after the 2nd dose. Vaccine associated rash was mild (mean 14 lesions, range 1-100). Vaccine type virus was isolated from 1 adult with a total of 8 lesions, 1 mo. After vaccination; there was no spread of vaccine virus to others. Seroconversions to VZV, measured by fluorescent antibody to membrane antigen (FAMA) were: after 1 dose 136/169 (80%), & after 2 doses 114/121 (94%). 22 seroconverted only after the 2nd dose; 7 (6%) failed to seroconvert after 2 doses. Positive antibody responses have been detected after 1 yr in 44/67 (66%), after 2-3 yr.In 19/28 (68%), & after 4-6 yr in 10/13 (77%). Ten have had a household exposure to varicella after as long as 7 years (mean 3 yrs); 6 (60%) developed at least some evidence of clinical varicella with 1-40 lesions (mean 16) but no toxicity. Seropositives (5/10) rarely developed clinical symptoms; 1 had 1 vesicle. There were a total of 10 cases of mild varicella in adult vaccinees with 1-58 lesions, (mean 10), 4-72 months after immunization. Wild type virus was isolated from 2 MDs, but there was no spread. Clinical infection was likely to occur in those seronegative at exposure (7/8, 88%) but the illness was still very mild. Varicella vaccine has the potential to control but not prevent nosocomial varicella. Varicella vaccine is less protective for healthy adults than for healthy children, but it modifies the illness even if VZV antibodies are no longer detectable.
Level 3 Immunization Requirements
All students registered in a Clinical Program is required to have a physical examination. This examination must be signed by a health care provider. This physical must be recorded on the UAB Student Health Physical Form
Given the nature of their work, students engaged in health professional training programs could have a higher risk of contracting Rubeola, Rubella, Mumps, Tetanus, Diphtheria, Varicella, Tuberculosis, Pertussis, and Hepatitis B. All UAB students in the Joint Health Sciences programs and in the Schools of Medicine, Dentistry, Optometry, Public Health, Nursing, and Health Professions are required to be immunized as follows:
General
The UAB Student Health Services will provide such immunizations and titer testing on a fee-for-service basis for any student who needs to meet the UAB immunization or titer requirements. Students may choose to fulfil these requirements at your local health department or a private physician.
Exceptions
Exceptions to this policy may be made in limited circumstances for students who can document medical and/or other contraindications to the vaccine. Requests for exceptions must be submitted to UAB Student Health Services for consideration and approval.
Students enrolled in online classes only, with no on-campus classes, are exempted from these requirements.
Ask The Experts
Many diseases are vaccine-preventable. Because of aggressive and successful vaccination efforts, diseases such as polio, diphtheria, and measles rarely affect American children today. Should American parents continue to have their children vaccinated routinely? Why is the vaccination of children around the world a matter of concern to Americans?
1. Eradicating or controlling disease with vaccination
LINDA HARRAR, MODERATOR: Our first question is regarding diseases that can be eradicated through global vaccination campaigns, like smallpox and polio. But others require new rounds of vaccination with each new generation of children. Will you please explain the differences between those that can be eradicated versus the challenges of keeping up with the momentum of vaccinating each new generation of children year after year?
DR. PETER SALAMA: Some diseases, such as polio, have no animal or environmental reservoirs and are therefore able to be eradicated. Polio is a great example of a disease that we've had a lot of success in. The cases today are less than 90 percent of the number of cases that we had when we started the polio eradication program in 1988.
DR. LOUIS Z. COOPER: Polio and smallpox are two diseases that are unique to man, and so it isn't a question of having to get rid of an organism that can live in the soil or live in other animals. That's why it was possible to really eliminate smallpox, and why the expectation is that we should be able to eliminate polio pretty much, too, because it doesn't lurk in some other animal where it can come back to haunt us, lurking in some non-human sources — what Dr. Salama means by "reservoir."
MODERATOR: Dr. Salama, can you give us a short list of those [childhood diseases] which need new rounds of vaccination with every successive generation of children?
SALAMA: There are the major diseases that we need to do rounds of vaccination for in the developing world: measles, diphtheria, pertussis or whooping cough, and tetanus. Increasingly as well, there are new vaccines that are available in the developing world and have been available for some time in developed countries, and these include vaccines against Haemophilus influenzae, which is a type of bacteria that has caused both meningitis and pneumonia. In the future we're also hoping to have widely available vaccines against pneumococcus, which is a bacterial cause of pneumonia, and against rotavirus, which causes a high rate of diarrheal mortality and morbidity in developing countries.
MODERATOR: And is it true, Dr. Cooper, that when a person becomes sick with a cold or a common illness that they develop antibodies that help fight infection if they're exposed later to the same bug, kind of like a natural vaccination?
COOPER: There are many infections that, as you fight the infections, you develop immunity which protects you from being re-infected again. Unfortunately, there are so many different variations on some of the bacteria and viruses that that protection may not be universal. The illnesses for which we have vaccines that Dr. Salama mentioned are characterized by immunity once you've had the infection — if you have measles vaccine, for example.
MODERATOR: Dr. Hedberg, what are the challenges that you face as a person trying to coordinate vaccination efforts within the U.S. With each new generation of children who need vaccines?
DR. KATRINA HEDBERG: From a state level, one of the problems has been, if you will, the success of public health in vaccinations. There are many parents today who aren't familiar with some of the diseases that we still want to vaccinate against. For example, we haven't seen diphtheria in the United States for decades. Measles, while many middle-aged people had it as kids, once the vaccination came, rates plummeted. So for a lot of parents, the urgency to continue to vaccinate children isn't the same as it perhaps was in the '50s, when we saw an epidemic polio and children becoming paralyzed from that.
One of the challenges that we have is to educate parents about the need to continue to immunize children in the United States, both against diseases that may exist in other parts of the world that get imported to the United States — and that would be true now for measles, and some polio cases — but also the need to vaccinate, or to continue to vaccinate, as new vaccines are developed, for example, against meningococcal disease.
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2. Weighing the risks of vaccination
MODERATOR: Do vaccines carry some risk of side effects? A person who wrote to us said: "I am not against vaccination, but I think parents should have all the information. Are doctors not responsible for telling patients about potential risks and side effects?"
HEDBERG: Whether it's vaccination, medical treatments, or drugs, there are side effects with all of them. The question is always: do the benefits outweigh the risks? I think some vaccine-preventable diseases — for example, pertussis — can kill infants, and so it's important for people to realize that the downside of not vaccinating is some of these diseases that are very severe will continue to occur.
But the questioner, the person who wrote it, is absolutely right: there are some risks. When parents give vaccinations or the pediatricians give vaccinations, parents are required to read about the side effects and to sign an informed consent. So I do think that it's important for doctors to be up front that, for example, some of the children can develop a little bit of fever; sometimes it's uncomfortable in the arm, etc. So there are certainly some complications. But most … vaccines are relatively mild compared to the diseases themselves.
COOPER: Dr. Hedberg said it just right. It's the doctor's obligation to be sure that families understand the benefits of immunization and the risks, because nothing is risk-free. In fact, in the United States, we created a whole program called the Vaccine Injury Compensation Program [VICP] to take care of any of the consequences, the costs of the consequences, of the rare events that occur after vaccination. The bottom line is that the benefits of immunization far outweigh the risks, which are fortunately — serious risks are extremely rare.
SALAMA: Just as in developed countries and developing countries, there are also potential side effects from vaccines. It's important to remember that the more common side effects are self-limited, really are not serious, and the serious side effects are, in fact, exceedingly rare. In terms of the benefits, clearly the benefits of vaccination outweigh the risks. It's important that people understand that immunization benefits, both in developed and developing countries, not only their own children, but also by contributing to population immunity, the whole community.
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3. Herd immunity
MODERATOR: When parents in the United States choose not to immunize their children, how low can vaccination rates go before we lose the protective effect of herd immunity on children? And, can you please explain what herd immunity means?
SALAMA: Herd immunity is when the population immunity is high enough to decrease the individual risk of contracting a disease without that individual having to be vaccinated. It varies from vaccine to vaccine. For example, with a very infectious disease such as measles, herd immunity is not achieved until somewhere around 95 percent of overall population coverage. But herd immunity for some diseases can be achieved at lower rates of coverage.
MODERATOR: So, Dr. Hedberg, couldn't one imagine that a parent might say, "Well, I'm just going to depend on other people to have their children vaccinated, and that way my child won't have to carry the risk of side effects"?
HEDBERG: What we find is that, at least here in Oregon, we've had a few measles cases that have happened. These have been primarily what we call imported cases, so measles in students from other countries in Asia or from other parts of the world that have much lower measles vaccination rates. So measles is continually being reintroduced into the U.S. If there aren't high enough immunization rates here, you can actually start to see clusters of cases that will occur in this country. So herd immunity works fine if in fact your community is completely isolated and these diseases aren't being reintroduced. Then you will be protected by those around you.
The problem is that any of these diseases are literally an airplane flight away. People travel a lot, both people from this country who travel abroad and vice versa. There are lots of foreigners who come into the United States, to study and as tourists, etc., so we are as a society continually being re-exposed to these diseases. So herd immunity does pretty well in limiting the spread. For example, we haven't had any large measles outbreaks, but we often have a case or two that might occur in people in the United States as a result of being exposed to some of these imported cases.
COOPER: The fact is that if you fail to immunize your child, yes, you do reduce ability to have herd protection. But equally important, you're increasing your own child's risk of getting measles 20 to 30 times over children who are immunized. So failure to have one's child immunized in the United States, where we have high levels of protection, not only reduces that protection for other people, but it also reduces dramatically the protection for your own child.
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4. Is there a link between autism and vaccination?
MODERATOR: Is there a link between autism and vaccine? What is the situation with thimerosal, a mercury-based preservative that has been used with vaccines? Are other preservatives available or being developed?
SALAMA: There is no established link between autism and thimerosal. This has been well studied, including peer-reviewed literature and reviews of all the established data that we have globally that has been published in the academic journals, and none of these studies have shown a link between autism and thimerosal. There are alternatives to thimerosal preservatives, and these are being gradually introduced around the world.
HEDBERG: We've certainly encountered the concern. I think thimerosal has been phased out in vaccines in the United States, other than perhaps some of the influenza vaccines, so it is not being used. But I agree with Dr. Salama that, in fact, the studies that have reported a link between the two have not had sound methodologies. There have been problems, etc., and there have been numerous other studies looking at specifically this issue that have not found the link. That said, because of the concern, it is being addressed, and thimerosal is being decreasingly used because of the concern.
COOPER: This has been an enormous concern, and continues to be in spite of the series of studies from around the world that Dr. Salama mentioned. It fails to come up with a link. If autism is as common as it's thought to be, certainly the kinds of well-defined, well-described epidemiologic studies would have found a relationship, and we've just not been able to find it. Until we better understand what the real causes of autism are, there will continue to be people who have serious concerns.
HEDBERG: What sometimes happens is that a child who is diagnosed with autism — and autism isn't something that is suddenly diagnosed, if you will; obviously it's developmental, and gradually kids are being diagnosed if they've shown that they're having problems with socialization and these kinds of things.
But if a child is diagnosed with autism in the week or the month after an immunization, people make a link. If the child is diagnosed in the week beforehand, that link isn't made. But these negative associations aren't the ones that are publicized; it's the positive associations that people make that get publicity. So I think the timing is always true. People remember events that happened right before they got sick or right before their child got sick. They tend not to remember a similar series of events that happened when they're well. They're less likely to remember what food they ate, let's say, or whether they got a vaccination or whatever, because they're perfectly well, and those are part of their day-to-day.
It's what we call "recall bias." People tend to remember events that are happening immediately before they develop some symptoms or illness, or their child has that final diagnosis of autism.
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5. The world's deadliest diseases
MODERATOR: What are the top deadliest diseases that do not yet have vaccines? And are vaccines the key to their being eradicated?
COOPER: I think we all agree that the big three are malaria, tuberculosis, and HIV/AIDS. These are conditions for which there is not a solid protective vaccine of the kind that we now enjoy with measles, polio, smallpox, and the like.
SALAMA: I agree that those are the big three, but they're the big three in the adult population. And as a representative of UNICEF, I would like to then talk about the worldwide population of children and what are the big diseases in this group. These are diarrhea, pneumonia, malaria, measles, and neonatal causes of death. And in children worldwide, we're really looking at pneumococcal disease, measles, rotavirus, and Haemophilus influenzae [Hib] as the big diseases that are either currently vaccine-preventable or will be in the near term. We also hope to have a vaccine against malaria in the future.
Let's take pneumonia. We're really looking at bacterial causes of pneumonia for which we have vaccine currently available, such as Haemophilus influenzae vaccine, or for which potentially we will have vaccines available in the developing world. They include another bacterial cause of pneumonia. These two vaccines can save around 1.2 million deaths per year.
Infant and childhood diarrhea is also a major cause of death in developing countries. Rotavirus vaccine is being rolled out in some countries in Latin America next year, and there's a high possibility that it will be rolled out in other countries around the world in a couple of years. This vaccine has the potential to reduce deaths due to diarrhea by around 400,000 per year.
MODERATOR: Help us to understand why measles and diarrhea are killers in the developing world. We're used to people having them here and not dying.
SALAMA: If we take a step back and look at what are the big causes of death among children in developing worlds, there's really the big five. It's diarrhea, pneumonia, malaria, measles, and neonatal causes. These are relatively uncommon causes of childhood deaths in developed countries.
Some of the reasons for this? Well, there are multiple reasons, but probably first and foremost is the fact that under-nutrition in children in developing countries is a very prevalent problem. Around 50 percent of the kids have some form of malnutrition, and it decreases their ability to fight off infection, which is one dimension. The other big contribution, of course, is very poor water and sanitation and hygiene in certain countries, which is of course a very big factor, as well as we tend to have population crowding in these countries. Of course that facilitates infectious disease transmission, particularly for respiratory infections such as the bacterial pneumonia that I mentioned, pneumococcus. So these are some of the underlying reasons these diseases of poverty are affecting children globally.
HEDBERG: You mentioned whether vaccines were a complete answer, and I think for a lot of infectious diseases, it's really a variety of things. Vaccines are an extremely important part of it. Clearly antibiotics and treating these diseases, which, once again, is much more difficult in a lot of the developing world, is an important element of controlling certainly deaths from these diseases. But as we know, there's the rise now of resistant bacteria and viruses, so that the treating of these diseases is becoming increasingly problematic.
Certainly sanitation is very important to limiting the development of diarrheal diseases. Once again, we have fewer of them in the developed country because we have much better sanitation and drinking systems. So those need to be developed alongside of making sure that kids get vaccinated. So I don't think it's necessarily all one or the other, but clearly the improvements in hygiene, nutrition, and general status can't solve all the problems. It needs to be vaccination in addition to those other things.
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6. Why prevention is a hard sell. Economic obstacles.
MODERATOR: Why is prevention such a hard sell? I remember [former Director of the Centers for Disease Control and Prevention (CDC)] Dr. William Foege saying, "Nobody ever thanks you for saving them from a disease they didn't know they were going to get."
COOPER: One of the great frustrations for all of us is how hard a sell prevention is, and we experience it in our own lives. People put off things that are not staring them in the face. One of the challenges in the United States with immunization is that we're victims of our own success. As has been mentioned, not only don't today's [parents] know about measles, polio, and diphtheria and meningitis; half the doctors who are now practicing in the United States are young enough so that they don't have much experience with these conditions either.
I'd like to kick it up a notch. The fact is that in spite of success, we still are not spending enough on vaccines to immunize the children that are out there now. And though there's been great progress in the work of UNICEF and the Red Cross, WHO [World Health Organization], and CDC reducing the measles deaths in the world from a million down to now less than half a million, we still have children around the world who don't get immunized. As I've talked to the people that Peter works with in UNICEF, we still don't adequately fund UNICEF for the vaccines that they need to give all 130 million children who will be born this year the basic vaccines, let alone the new vaccines that Dr. Salama mentioned: rotavirus, rubella. Rubella still causes well over 100,000 birth defects a year, and yet rubella isn't even included as one of the vaccines in the WHO Expanded Programs of Immunization (EPI), considered as the goal for global routine use in all children in both developed and developing nations.
MODERATOR: Rubella is what we commonly grew up understanding to be called German measles — is that correct? — [as opposed to] regular measles.
COOPER: Yes. It's a mild illness except when it occurs during pregnancy. Then it creates a high risk of serious birth defects, and an enormous burden of over 100,000 cases a year around the world, for example.
MODERATOR: What would it take to get all the world's children immunized for the diseases that we know how to immunize for? Can you tell us what the challenges are, both money and infrastructure?
SALAMA: One of the challenges is one you mentioned: we have to really make our case in a much more powerful way, as Dr. Cooper was alluding to. I think it's really very important that we have people understand the significance here. There are more than 10 million children dying each year around the world, and two-thirds of the deaths are preventable deaths. Around a quarter are currently or will very shortly be vaccine-preventable.
So if we have 1.4 million deaths that we could be preventing today with our current available technology and vaccines, an additional million could be prevented within a couple of years if we could find the money and means to get vaccines all around the world.
In terms of the argument we should make, I think there is a powerful argument to be made on the basis of just the sheer number of lives we can save with this prevention. But the other side of the argument is that there's increasing data there, including a recent study by the Harvard School of Public Health, to suggest that in terms of investing in developing countries, actually investing in vaccine, they're good investments not just for the health benefits, but also for the education and productivity benefits that accrue from having a healthier cohort of children.
There's a really, really interesting study which was featured in The Economist a couple of weeks ago, basically showing that children who were vaccinated in developing countries had a much better IQ in test scores and much better productivity in later life. So we want to get this data out there to the policymakers, the ministers of finance, and the key people making decisions on these national decisions on resource allocation.
In terms of what it would take in monetary terms, you may know the news that the WHO and UNICEF has recently published a new Global Immunization Vision and Strategy, and in that we estimate that we need to increase the expenditure on vaccines, which is estimated to be around $2 billion as of 2006, to around $6 billion to $9 billion by 2015. So we really need to increase it threefold within the next 10 years to be able to give access to these lifesaving interventions for children around the world.
COOPER: To put that into perspective, in the United States we spend over $6 billion just on the hardware of the coated stents that we use for people who have coronary artery disease and the pacemaker defibrillators that we put in old people's chests. Those two pieces of hardware alone — all aimed at people in the latter years of their life and whose effectiveness really relates to allowing people to play tennis another six months longer without chest pain — are equal to what it would take to fully immunize the rest of the 130 million children born each year who don't have access to vaccines. That's a startling number.
MODERATOR: In other words, it's not a matter of not having enough money in the world. Why might vaccines have a relationship to increased IQ?
SALAMA: Again, without going into the biological arguments in the papers that have been published recently, basically the theory is that these children are basically healthier children and therefore learn more quickly and more effectively in the crucial years for cognitive development.
MODERATOR: So it's a matter of their growth not being stunted, perhaps because they're not so ill, and therefore they can get the full benefit of the nutrition they receive? Would that be part of it?
SALAMA: That would be part of it, yes.
COOPER: And they don't miss as much school.
HEDBERG: Well, certainly there is the question of why preventability is such a hard sell. We know that when somebody, a child or somebody else, is stricken with a disease, they become a poster child for a particular disease. So a child that has cancer, that's a terrible thing, and they can become a poster child for preventing or treating that disease. I think the quote that you mentioned from Bill Foege is really true: it's hard to have a poster child when they haven't come down with the disease.
The other part of prevention that makes it a little bit of a hard sell in this country is that a child or a person feels completely well; they go and get shots, and their arm hurts, or the kid is fussy or whatever, so that the benefits aren't quite as immediate as if you are sick, let's say, and then go to the doctor and get put on an antibiotic and you see [an] immediate benefit.
So I think that people, when they're sick and it's in the forefront of their mind, they want to go in and get treated and feel better. But with prevention, we need to ratchet up what the problems are for a whole society, whether it's just in the United States or the global society if we stop paying attention to these immunizable diseases. They clearly cause significant morbidity and mortality — that is, disease and death — in the developing world, but they also cause disease and death here in the United States, too.
In Oregon, we're currently having, as in much of the country, a large outbreak of pertussis — that is, whooping cough — which is vaccine-preventable. And we've had lots of cases that have occurred, and even some infant deaths. So here's a disease that there is a vaccine for, but we have pockets of communities where people [have] much lower immunization rates, less herd immunity, and we are starting to see some of the consequences of that.
SALAMA: I have one more point on the question of prevention. It's just a follow-up of Dr. Hedberg and Dr. Cooper's points, really. But I think this is an important element here, which is that there isn't really a political constituency for pushing vaccination. This is a benefit that accrues mainly for children who, both in developed and developing countries, don't really have much of a political voice. I think it's really important that Dr. Cooper's analogy to cardiac technology and the amount of money spent on that — the analogy in the developing world is that it's a lot easier for a politician to present a new hospital to his constituency as something that he's tangibly done for his community than to present his new approach to increasing vaccination rates among children.
I think it's important that we change that political dimension of the equation to really make politicians understand that it is important that children survive, and that there are real economic benefits to them being healthy as they reach a new generation.
COOPER: This week our president pledged more money to develop a flu vaccine for a flu that doesn't yet exist than it would take to immunize all the children in the world for all of the childhood diseases for which we currently have vaccine. That was a political statement, and it was a good one. That is to say, we should be investing in the development of appropriate vaccines to prevent pandemic and epidemic influenza, but we shouldn't have to create these kinds of crises to have the adequate funding, which is really quite modest in the grand scheme, so that children throughout the world would not have to die from measles or diarrhea or polio, which they still do.
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7. Refusing vaccination: Cultural reasons
MODERATOR: Are there sometimes cultural reasons for people to resist vaccines? And might there be some real historical abuses that might make people suspicious of nationwide campaigns? The person who submitted this question has given the example of India in the late 1970s, when many poor Indians were coerced into sterilization. Might this be a reason why poor Muslims in the state of Uttar Pradesh in India have been resistant to the polio initiative there?
SALAMA: There's no doubt that cultural factors play an important role in communities' and individual families' acceptance or denial [of] immunization. One important example has been [in] Nigeria, where in Kano state, at the end of 2003, community and religious leaders really lost confidence in the polio vaccination program and the safety of the vaccine and basically advised their community not to accept it. This has led to a tragic outbreak of polio that has crossed more than 12 countries, and we now have examples of polio derived from the Nigeria epidemic in places as far afield as Indonesia. And it's really set back the Global Polio Eradication [Initiative] probably by at least a year.
So we shouldn't underestimate the importance of communicating the safety and effectiveness … with communities in ways that are culturally acceptable and are readily understandable in those communities. I'm sure there has been in history instances in India and I'm sure in many, many other countries where we haven't done enough to explain why the vaccinations are critically important for individuals in communities. I guess that's something that we all need to be aware of. Keep aware of the history, but also help people understand that really this is in the benefit of their own children and their families.
COOPER: Rendering your healthy child to the arms of someone to give a vaccine is really an act of trust, and there have been so many reasons why there's been erosion of trust — erosion of trust in institutions, erosion of trust in politicians and so forth around the world. And with the Internet, bad news travels fast, and rumors travel even faster than truth. So it's no wonder that we've had the kinds of problems that we faced in Nigeria that Peter pointed out that have given us such a setback with polio. It's a reminder that we just do need to work harder to be aware of the education that's required if we're going to get full immunization.
Some of us think that not only can polio be eliminated, but that measles can be eliminated, too, and that that's not an unreasonable goal in a reasonable period of years. All it takes is the will to do it.
HEDBERG: With vaccination, I'm not aware of any historical abuses. But certainly we have seen them with, for example, the very infamous Tuskegee [Syphilis Study], where patients with syphilis in the South, primarily African American men, were allowed to go untreated to see how syphilis eventually developed in its later stages. I think that there is a history of the established, relatively wealthy, predominantly white community, at least in the United States, losing the medical trust of those in other communities for sound reasons.
I agree with what's been already said. It is a little bit of an uphill battle to say, "There were abuses that happened in the past, but trust us now." We need to earn that trust as well. Once again, that's one of the challenges with prevention, is that through experience, we need to see that by more immunization, less disease is happening, particularly some of the severe diseases that are still occurring.
But in the case that we talked about in Nigeria, unfortunately [it is] only after children start developing polio, and you see paralysis in these young children, that then the community can be aware that yes, in fact, immunizations may be helping to prevent it. So I do think that's a challenge.
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8. Is there a link between the smallpox vaccine and HIV?
MODERATOR: Is it possible that the people who received the smallpox vaccine in the 1970s, which involved tearing the skin with a needle, might have been exposed to HIV or other blood-borne disease?
COOPER: The answer is no, it's not possible. First of all, the smallpox vaccine as given in the '70s didn't really involve tearing the skin. In fact, it doesn't draw blood, so it would be a poor method for transmitting HIV. Secondly, HIV didn't appear on the scene until well after we stopped using the smallpox vaccine.
It's interesting how those rumors come up, because there was a whole book written suggesting that HIV was spread by the original trials of polio vaccine in Africa and the making of polio vaccine in tissue culture from monkey kidneys. Sound science has laid that to rest, but it certainly captured a lot of attention.
Whenever there's something that you don't know the answer to — because we don't know the basic origin of HIV — people come up with some remarkably wild theories. And I think this linking of smallpox immunization as a means of spreading HIV would have to be put in that category of a wild theory with no basis in fact.
SALAMA: Dr. Cooper is absolutely right. It's extremely unlikely that the smallpox campaign has anything to do with transmission of blood-borne diseases on a wide scale, at least with HIV. But what is important, I guess, in this question is the link between transmission of blood-borne disease and the importance of injection safety. That's something that we at UNICEF invest a lot of time and money in, in terms of really trying to find the technologies that can decrease the risk as much as possible due to human error of transmission of blood-borne pathogens inadvertently.
For example, UNICEF has been using for some time now [auto-disable, or self-locking] syringes, which do not allow health workers in developing countries that may have fairly minimal training to use the injection more than once. That's when a simple technology can really revolutionize immunization globally and the benefit of risk analysis by really decreasing the sort of risks that that question alludes to.
COOPER: It's one of the reasons that people are looking for other ways to deliver vaccine like nasal spray or drops, so that we can even eliminate the need for needles and syringes, even [the] expense of the auto-[disable] ones. But we're not quite there yet.
HEDBERG: As I was thinking about it, [it] implies that there was something happening with needle safety, that somehow breaking the skin with the sort of multi-punctures with the bifurcated needle was somehow being spread. And that's been mentioned already, the fact that HIV wasn't even on the scene yet at that time, as well as some of the issues around just needle safety in general.
I think it's highly unlikely that it would have been spread that way. But it does raise the issue that's already been talked about: once again, prevention is a hard sell. And so when disease occurs, people are looking for some ways to explain that, such as HIV, coming up with that in the early '80s without yet knowing exactly where the virus came from, the origins of it. So people are looking for it. That's one of the challenges of public health, that we need to quell these rumors. We need to be doing as much research as possible to really find answers to those questions, because it does reflect, obviously, some discomfort that people are having, both around HIV as well as around the immunization in general.
But I do agree that having new delivery methods would be beneficial. Routine inactivated influenza vaccine is an injection, and now we have FluMist, which is a nasal spray, and a very effective vaccine. Once again, that eliminates the need for needles at all. So developing more of those delivery methods is going to be really useful.
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9. Can multiple doses of a vaccine be dangerous?
MODERATOR: Here are some related questions. During the confusion of a mass vaccination campaign, might it be possible that some child might receive an unnecessary repeat dose of a vaccine? Is it likely that any bad effect would occur from this? When we vaccinate for polio in the U.S., it requires a series of three doses. How are the children in India who receive a single dose protected from the disease?
SALAMA: First of all, on polio in India, it's true that in each campaign in developing countries, children receive one dose of polio. But in actual fact, in settings where polio is still a threat, it's quite likely, in fact throughout India very likely, that children are actually vaccinated many, many times for polio. This is because the campaigns occur many times a year, and children are also vaccinated through routine immunization services.
To give you a figure, [it] takes about five doses of polio in developing countries to actually develop widespread immunity on a population basis, so we do actually recommend multiple doses of many vaccines, including polio, in developing countries to achieve immunity. And there is no data to suggest those multiple doses are unsafe for those children who receive them.
COOPER: There's another big issue. Through most of the world, we still use the oral polio vaccine, which, in fact, contains three different strains of poliovirus, but it's alive and replicated. In the United States, we've gone back to using a killed polio vaccine, and that killed polio vaccine, to get high levels of immunity, requires the multiple doses.
So that's why the program in India that can be effective looks different from the current practice in the United States. There's a lot of safety data about multiple doses of vaccine, and it does not appear to add risk if the child gets an extra dose or two of any of the known vaccines.
HEDBERG: Well, in fact, the question arises a little bit from another angle. I agree that having multiple doses of one of these vaccines, if anything, will just boost a person's immune system. It won't cause them to get sicker; it won't hurt them more.
But one of the issues that we have in the United States is that, of course, vaccinations and vaccine delivery is somewhat expensive, and so having a child get repeat immunizations who doesn't need them can end up being quite costly for the system. We in Oregon, as in a number of other states, have actually developed vaccine registries that the children's immunization schedule gets entered into. Their name is entered at birth, and then they're tracked as they get immunizations. If they see multiple providers, a new provider can look at the child's data in the immunization registry and say, "Oh, they already got this vaccine at a previous provider; they don't need to get it."
We're trying to help limit the overall costs of having kids come into a clinic, get vaccine, etc. But that's sort of the cost side of it. Once again, if the child gets a second vaccine or has had multiple shots that doesn't really need them, there's no data to show that that is harmful to the child.
MODERATOR: We have another questioner who says she particularly is concerned about fiber myalgia [better known as fibromyalgia]. For people who may have compromised immune systems through diseases or chronic illnesses like multiple sclerosis, HIV/AIDS, or fiber myalgia, should they get vaccines when they travel to developing countries?
COOPER: The answer is there are so many variations on the theme, that's exactly why people should seek out their own individual physician and allow their condition to be individualized.
HEDBERG: Part of it is that when people are immunocompromised, they may be at slightly higher risk of complications of some vaccines, but they're clearly at higher risk of developing some of the diseases as well. And not all vaccines are the same. Once again, the live polio vaccine isn't being used so readily in the United States anymore, because live virus vaccines like that given to a child in the household could pose a risk to others in the family who were immunocompromised. Now, clearly that's different with the current killed polio vaccine that we're using here, which does not pose that risk to others.
I do think that [because] each case is different, then you're going to have to talk about not only what particular condition the individual has, but which countries they're traveling to and which diseases are endemic in those countries and which ones they should potentially get immunized for depending on where they're traveling. I don't think it's a blanket statement. But people who are immunocompromised should continue to seek medical care, and if their physician or provider recommends vaccinations, they should be getting those.
COOPER: A classic example is varicella, or chickenpox, where the chickenpox vaccines, the varicella vaccine is important for children who are immunocompromised, because should they get exposed to the wild varicella or chickenpox virus, they can have very serious, and sometimes fatal, illness, whereas they tolerate the vaccine quite well. So it's complicated, and that's why one has to see an individual physician.
HEDBERG: For example, with influenza, clearly getting the inactivated flu shot every year is a good thing. They may not be indicated to get the FluMist or the live attenuated nasal spray that we were talking about.
SALAMA: I would like to flip the question around a bit in terms of children in developing countries, even in settings where, for example, HIV prevalence may be high, [but] we still recommend the usual immunization schedule for vaccine-preventable diseases in those countries.
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10. Tuberculosis
MODERATOR: Let's move on to a question about tuberculosis. This questioner says: "I received a BCG [bacille Calmette-Guérin] vaccine against tuberculosis in 1975 and in 1980. Can I get a booster or additional vaccine to protect against TB?"
COOPER: BCG is a vaccine used in infancy to protect against tuberculosis that's used in many parts of the world, and it does decrease the spread of tuberculosis. By the time someone is old enough to have received all the doses that were just described, I don't think there would be any indication for BCG.
MODERATOR: While we're on tuberculosis, and we've just been speaking about HIV/AIDS, can Dr. Salama comment on the relationship between HIV/AIDS and tuberculosis and give us some sense of how widespread the tuberculosis, the bacterium is, and how it interacts with HIV/AIDS?
SALAMA: Based on the previous question on BCG vaccine, I agree with Dr. Cooper's point, and just to also point out that the biggest reason to give BCG is actually to decrease the incidence of tuberculosis meningitis in childhood — that's the strongest reason to give them the vaccine. So again, in general, there wouldn't be much indication for further booster doses later if that is the objective.
In terms of the relationship between HIV and TB, it's really a crucial relationship, particularly for developing countries, and with a particular emphasis on the bloc of countries in eastern and southern Africa where HIV prevalence is high. It can be as high as almost 40 percent in the highest prevalent countries, such as Swaziland and Botswana in southern Africa. It's in these countries where tuberculosis is actually the leading cause of deaths among HIV-positive individuals. So there's a real synergistic relationship between these two diseases which attack the body's ability to fight off a whole range of other diseases as well.
So TB and HIV are, as I've mentioned earlier, really large killers, and especially in combination in adults, particularly in southern Africa. But increasingly there is recognition of the importance of HIV and TB in children. TB is a particularly difficult disease for children because it is a much harder disease to recognize, to diagnose, and to treat in children. So we're really starting to grapple now with trying to discover the extent of tuberculosis in HIV-positive children in Africa, for example, and also grapple with new ways of diagnosing them, both for TB and increasingly for HIV …, and then lastly, how to treat these children in settings where access to and the quality of health care facilities are extremely poor. So in some ways these are really very synergistic diseases. Both the diseases are very well documented for adults, particularly in southern Africa, and increasingly we're becoming aware of the burden of these two diseases in children throughout the countries in Africa.
HEDBERG: Just a couple of things about tuberculosis that people need to be aware of. BCG, the vaccine, was never widely used in the United States. We adopted a different strategy here, which was to identify people with active TB and then identify who their contacts were, and do skin testing on them to see whether they've been infected and need to take the antibiotic INH [isoniazid] to them to prevent them from developing the disease later on.
There are different strategies that are used in developed countries and in developing [countries] depending on how prevalent the disease is, how widely available treatment is, and that we have the ability in the U.S. To follow up on individual cases. In a lot of the developing world, they don't. That doesn't mean that it's not appropriate for BCG to be used in parts of the developing world, particularly against this infant TB meningitis. But that's part of the reason it isn't used in the United States — once again, a lower prevalence and a different strategy.
This is similar to what we've already been talking about with the polio vaccine. Here in the United States we used to use the oral live virus polio vaccine. Then, as the prevalence of the disease dropped, we started to use more killed vaccine. But that doesn't mean that it's not appropriate for the developing world to continue to use oral polio vaccine. Part of that is to understand once again what the epidemiology or what the disease patterns are in different parts of the world, and then address them with enough strategies for those areas.
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11. Vaccines and the elderly
MODERATOR: Now if we could switch to the other part of the population: our older folks. Is it important that they receive vaccines against pneumonia and flu?
HEDBERG: One of the reasons to look at the epidemiology and local disease patterns is to figure out who's at highest risk. Certainly in the United States each year, we have several thousand people who die of influenza. I'm not sure that the average citizen thinks about influenza as frequently being a fatal disease of the elderly.
The elderly similarly may not respond as well to the vaccine, but they are nonetheless in the highest risk group, and so we recommend that people over the age of 65 get routinely immunized with influenza vaccine. Now that has actually been broadened because what we realize is t
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