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Researchers Identify New Antibodies That Could Improve Flu Vaccines

Researchers from the University of Pittsburgh identified a new class of antibodies capable of combating multiple forms of the flu virus.

Scientists believe these new antibodies could create a flu vaccine with broader protection for different strains.

While the flu may not be a big health concern for many people, it can be for certain groups.

Annual influenza vaccines are recommended for everyone, especially those in high-risk groups.

Because influenza viruses are very diverse, the current vaccine tends to work better for certain strains and is less effective against others.

For most people, coming down with influenza — more commonly known as the flu — is not a major health issue. They will feel sick for four to seven days, then symptoms will subside.

However, there are populations where the flu can cause more serious health concerns, including older adults over the age of 65, pregnant people, children under the age of 5, and people with certain medical conditions such as heart disease, diabetes, and asthma."

This is why groups like the Centers for Disease Control and Prevention (CDC) in the United States and the European Centre for Disease Prevention and Control recommend people get an annual influenza vaccine, especially those in high risk groups. A recent CDC health advisory warned that current vaccination rates against respiratory viruses are low in the U.S.

Because influenza viruses are always changing, influenza vaccines are changed yearly to protect against the strains predicted to be the most prevalent during flu season.

Additionally, influenza viruses are very diverse. For example, influenza A viruses, which contribute to seasonal epidemics each year along with influenza B, can be further divided into various subtypes before eventually being classified as individual strains. The flu vaccine works better for certain strains and is less effective against others.

Now, researchers from the University of Pittsburgh have identified a new class of antibodies capable of combating multiple flu virus subtypes.

Scientists believe this new research — published December 21 in the journal PLOS Biology — could help develop a flu vaccine with broader protection across different strains.

According to Dr. Kevin McCarthy, assistant professor of microbiology and molecular genetics at the Center for Vaccine Research at the University of Pittsburgh and senior author of this study, although antibodies provide the strongest protection against flu virus infection, the virus continually evolves to escape them.

"Multiple co-circulating flu subtypes make it difficult to get a match between circulating viruses and components in vaccines," Dr. McCarthy told Medical News Today.

"The antibodies in our study are capable of blocking multiple flu virus subtypes at once."

Although all approved influenza vaccines train the immune system to make antibodies against the flu virus for future encounters, he explained that the influenza virus evolves to evade these antibodies, which is why updated vaccines are needed.

"The antibodies we identified demonstrate that the hurdles to making improved vaccines that resist year-to-year changes may be lower than previously believed. We also highlight that specific vaccine manufacturing processes may introduce errors that may 'distract' the immune system from achieving an optimal response."

— Dr. Kevin McCarthy, senior study author

For this study, Dr. McCarthy and his team focused on finding a new to neutralize a small change found in some H1 flu subtypes that affect the sequence of building blocks that make up hemagglutinin — a type of protein that binds receptors on red blood cells to initiate the early stage of a viral infection.

According to scientists, while certain antibodies can stop H1 and H3 flu subtypes, they are no longer able to when the hemagglutinin is modified.

Using blood samples, researchers uncovered a new class of antibodies capable of destroying certain H3 flu strains and certain H1 flu strains with or without the hemagglutinin modification.

"We have two major findings," Dr. McCarthy reported.

"First, it appears that some humans can produce strong antibody responses that block infection by multiple influenza subtypes. A proper series of exposures is likely required but the barriers to achieving these responses are lower than we anticipated. With this information, improved vaccines can be designed and tested in the laboratory."

"Second, some types of vaccine production like growing vaccines in eggs can introduce changes that misdirect antibodies from their intended targets, the viruses transmitting between people," he added.

"Transitioning away from egg-grown vaccines, for which there are already alternatives, would minimize this issue."

MNT also spoke about this study with Dr. David Cutler, a board certified family medicine physician at Providence Saint John's Health Center in Santa Monica, CA.

Dr. Cutler said the discovery of a new type of antibody to protect against influenza offers promise to reduce the disease and death caused by various flu viruses.

"Whereas some viral diseases, like smallpox, polio, and measles, have either been eradicated or markedly reduced in their impact by vaccines, influenza continues to kill thousands in this country every year," he explained.

"What has made influenza more difficult to prevent is the rapid mutation of the virus, especially at certain sites, designated hemagglutinin and neuraminidase. These sites give the flu virus its classic designation, such as H1N1, or H3N2. Presumably, antibodies (that) latch onto more sites (that) have less variation could be more widely effective in protecting against the flu. This is the promise offered by this new class of antibodies."

— Dr. David Cutler, family medicine physician

Despite the positive potential for this research, Dr. Cutler cautioned there are many limitations to the promise that finding this new class of antibodies produced by vaccines will lead to the eradication of influenza.

"Flu vaccines have never been more than about 50% effective in preventing serious illness or hospitalization," he added.

"But certainly, there is room for improvement in flu vaccine development and administration. The same is true of other serious viral respiratory infections like COVID and RSV."

Dr. Cutler also said there are limitations in terms of people not believing they need to be vaccinated and that simply having antibodies against a virus does not necessarily mean that you will not become infected or ill from that virus.

"There are many other components of the immune system (that) aid us in warding off infection in addition to antibodies," Dr. Cutler continued.

"We are a long way from understanding all the complexities of the immune system which determine why some people acquire infections while others don't despite having similar vaccine and disease histories."

"Goals for future vaccine research include making them more effective at actually preventing infection, making them more resilient to mutations in viruses, and getting people more receptive to vaccine administration to prevent serious illness, hospitalization, and death," Dr. Cutler added.

CDC Urges People To Get Respiratory Disease Vaccines, Notes MIS-C Rise In Kids

The Centers for Disease Control and Prevention (CDC) today warned of an urgent need to increase vaccine coverage for flu, COVID-19, and respiratory syncytial virus (RSV) against a backdrop of lagging immunization rates and ongoing rises in respiratory disease activity from multiple viruses.

Heading off strain on health systems

In a Health Alert Network (HAN) notice, the CDC warned that ramped up respiratory virus activity could lead to more disease and strain healthcare capacity in the weeks ahead. High RSV activity is occurring across much of the United States, and respiratory disease is highest in the southern half of the country, with trends increasing in the north.

"Healthcare providers should administer influenza, COVID-19, and RSV immunizations now to patients, if recommended," the CDC said. It also urged clinicians to recommend antivirals for flu and COVID-19 to eligible patients, especially those at high risk for complications.

Healthcare providers should administer influenza, COVID-19, and RSV immunizations now to patients, if recommended.

Over the past 4 weeks, hospitalizations have risen 200% for flu, 51% for COVID, and 60% for RSV. Pneumonia hospitalizations in children have increased since September but are in line with past fall and winter respiratory disease seasons.

MIS-C concerns

Also, the CDC reported a rise in multisystem inflammatory syndrome in children (MIS-C), a rare but serious condition that can follow COVID infection. Since September 1, the CDC has received 30 reports of MIS-C, which can occur 1 month after COVID illness. Illness onsets occurred from August 6 to November 9, an increase over previous months.

MIS-C causes different body parts to become inflamed, including the heart, lungs, kidneys, brain, skin, eyes, or gastrointestinal tract, the CDC said in background information. The condition can be serious or fatal, but most children who are diagnosed with this condition get better with medical care.

Though scientists are still exploring why some children experience MIS-C, the CDC added that the best way to prevent the complication is to be immunized.

Overcoming immunization challenges

In today's HAN update, the CDC detailed the reasons for low respiratory virus vaccine uptake, based on a recent survey it commissioned. One was lack of a provider recommendation.

The CDC urged providers to double down on administering vaccines against all three viruses and included resources for addressing patients' concerns about issues such as safety and getting multiple vaccines at once.

Currently, flu vaccine uptake is roughly 40% for children and adults, but coverage with the updated COVID vaccine is much lower: only 7.7% in children and 17.2% in adults, according to CDC data. Uptake in higher in seniors for both vaccines. For the RSV vaccine, uptake is 15.9% in adults ages 60 and older.

Vaccines — Good For Adults Too

Vaccines — credited with eradicating diseases such as diphtheria, polio and measles in the United States — sometimes still get a bad rap.

Some people believe that they aren't effective or may cause dangerous side effects. Some say they are no longer needed because most vaccine-preventable diseases are no longer a major threat. Some think vaccinations are just for children.

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According to the December issue of Mayo Clinic Women's HealthSource, those beliefs are largely based on myth.

It's true that vaccines aren't 100 percent effective. But most routine childhood vaccinations reduce the likelihood of illness by 85 percent or more. During an outbreak, some who have been vaccinated still may develop the illness. However, they usually have a milder case.

The most common side effects from vaccines are minor and temporary — such as a mild fever or soreness at the injection site.

And, vaccines are still necessary. Diseases now rare in the United States are still common elsewhere, and they are just a plane ride away. Vaccines aren't just for kids, either. Talk with your doctor about vaccinations that might benefit your health.

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Adult vaccinations include:

Influenza: This vaccination is recommended annually for adults age 50 and older, adults with chronic illnesses or weakened immune systems, health care workers and those in contact with young children.

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Pneumonia: It's recommended for adults age 65 and older and those with a chronic illness, a weakened immune system or those whose spleen has been removed.

Tetanus, diphtheria and pertussis (Tdap) or tetanus and diphtheria (Td): Tdap is recommended especially for adults ages 19 to 64 and for those in contact with small children.

Measles, mumps and rubella: It's recommended for adults born after 1956 who weren't vaccinated as children.

Chickenpox: If you haven't had chickenpox or shingles, this is recommended.

Meningitis: This is recommended for adults at high risk because of a weakened immune system, for those traveling to certain countries; or during a community outbreak, for example, on a college campus.

Hepatitis A: It's recommended for adults with chronic liver disease, those who've been exposed to someone with the disease, or those traveling to certain countries.

Hepatitis B: If you've been exposed to infected blood or body fluids, use injected drugs or have multiple sex partners, this vaccine is recommended.

Shingles: One dose is recommended for adults 60 and older.

Source-NewswiseSRM

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