delta vaccine :: Article CreatorAnother COVID Vaccine? Yes, And Here's Why
This fall, prepare for the latest round of COVID vaccine Whac-a-Mole. Like the old arcade game, no matter how many shots we get, the enemy always pops back up.
But here's why the new shot, recommended by FDA advisers last week, makes sense: It targets a new version of the virus, the FDA panel said. It bolsters your body's ever-growing defense system. And it's a lot better than getting very sick or hospitalized.
Last year's shot isn't holding up. Protection against both infection and severe illness is waning.
"Effectiveness has decreased, as the time since vaccination has increased — and as new SARS-CoV-2 variants emerge," said biostatistician Danyu Lin of the University of North Carolina School of Global Public Health, who presented worrisome new data to the FDA advisory panel.
The old vaccine's effectiveness peaked one month after the shot, Lin's team found. After four weeks, the vaccines were 52.2% effective at preventing infection and 66.8% effective at preventing hospitalization. After ten weeks, effectiveness at preventing infection decreased to 32.6% while effectiveness at preventing hospitalization decreased to 57.1%.
By comparison, the Centers for Disease Control and Prevention says that with the annual influenza shot, "during seasons when flu vaccine viruses are similar to circulating flu viruses, flu vaccine has been shown to reduce the risk of having to go to the doctor with flu by 40% to 60%."
Last Wednesday, FDA's advisers, a panel of physicians from hospitals and universities around the nation, unanimously voted to recommend a new vaccine. Vaccine manufacturers Pfizer and Moderna say they were prepared to make updated vaccines available in August, pending final FDA approval. As in previous years, the U.S. Centers for Disease Control will make specific recommendations for the elderly, immunocompromised, youth and other groups.
The new vaccine will target a variant of the ever-evolving coronavirus called JN.1. Last year's vaccine was based on the XBB lineage of the virus.
Fortunately, the COVID virus isn't changing in a way that would make it a serious threat to most people — turning it into something far deadlier, such as Ebola. Each new version is a subvariant of the omicron variant that first appeared in 2021 and, though highly transmissible, hasn't proven to be particularly virulent.
But it is drifting in smaller ways, complicating our vaccine strategy. The original virus first detected in Wuhan, China, was replaced by the alpha variant, which was replaced by the delta variant, which was replaced by the omicron variant. A subvariant called BA.1, then BA.2, became the most common circulating versions of omicron.
Since then, the virus family has continued to multiply and diversify. There's an evolutionary arms race — as the immune system makes new antibodies, the virus develops new mutations. Each iteration seeks to offer some sort of advantage, such as an ability to sidestep the immune system or extreme contagiousness.
Late in 2023, variant JN.1 overtook the XBB lineage.
There's a wrinkle in the new vaccine strategy: By next fall, JN.1 may not be the dominant virus. Already, a subvariant called KP.2 is on the rise. But the new vaccine formula likely will be effective against both strains — and, because manufacturing takes time, a decision must be made now.
When compared against results from the original shot, the benefit of the new shot may seem modest. That's because the original vaccines were given to a completely unprotected population, with high risk of hospitalization and death, said Lin. Now, with four years of inoculations and infections, the general population has a wide range of vulnerabilities.
While the vaccine is free to both insured and uninsured individuals, this cost is still real. The federal government paid, on average, $20.69 per dose, and the cost of the new vaccine is likely to be higher. But vaccines save money by preventing hospitalization, lost productivity due to illness and potential long COVID.
Powerful combination vaccines are on the horizon, easing the chore of multiple shots. On Monday, Moderna announced that, in a Phase 3 clinical trial, its combination COVID and influenza vaccine generated stronger immune responses in older adults than individual vaccines targeting those viruses individually. A combo shot could be on the market as early as autumn 2025.
The FDA news comes as Americans are vaccine-weary and increasingly indifferent. The Centers for Disease Control and Prevention estimates that, as of March, a mere 28% of American adults have been vaccinated with the latest vaccine. Why bother with another shot? Medical experts say there are still many reasons to get the jab:
• Protection from previous shots, especially the primary series, has waned — so some people are getting very sick. Research shows that a large percentage of those hospitalized for COVID-19 had been vaccinated with the primary series but hadn't gotten an updated shot.
• Each additional shot helps. There is evidence that each vaccine or infection, especially in the first few months after receipt, provides added protection against critical illness and hospitalization. "Through multiple immunizations, your repertoire of immune cells expands," said Jeremy Kamil, a virologist at Louisiana State University Health Sciences Center Shreveport, who studies variant mutations. "Your body learns to make these very potent antibodies that are active against multiple strains of the virus, so it becomes harder for the virus to wiggle away from them. … You're much better defended."
• If you get infected, it will likely be less severe. Think of seatbelts and airbags — they don't prevent car crashes, but they boost your chance of survival. Similarly, COVID vaccines are not 100% protective, but an immune response will be more vigorous, so your illness will likely be briefer. Furthermore, research shows that vaccines help protect against Long COVID.
• Vaccines are easier on your body than infection. A sore arm and perhaps body chills are better than days of illness and perhaps hospitalization. "You're setting yourself up for success the next time you see the virus," said Kamil. "Your immune system will say, oh, I gotcha. I know who you are."
Third COVID-19 Vaccine Dose Boosts Immune Response Among Immunocompromised Patients
Most immunocompromised patients with suboptimal immunity following 2 doses of the COVID-19 vaccine have improved serological and T-cell responses after the third dose, according to study results published in The Lancet Rheumatology.
In the phase 3, open-label, multicenter randomized controlled OCTAVE-DUO trial, researchers in the United Kingdom aimed to assess the efficacy of a third COVID-19 vaccination among patients with primary and secondary immunodeficiencies. Immunocompromised adults who had an inadequate response to 2 doses of the COVID-19 vaccine were recruited from 11 hospitals across the UK.
Participants were randomly assigned in a 1:1 ratio to receive BNT162b2 or mRNA-1273. A subset of participants with lymphoid malignancies were randomly assigned to receive BNT162b2, mRNA-1273, or NVX-CoV2373 in a 1:1:1 ratio. The primary outcome was vaccine-specific immunogenicity, with neutralizing antibody titers measured 21 days after the third dose as a secondary outcome.
From August 4, 2021, to March 31, 2022, 804 participants across 9 disease cohorts were assigned to receive 1 of 3 COVID-19 vaccines: 377 (47%) received BNT162b2, 374 (47%) received mRNA-1273, and 53 (7%) received NVX-CoV2373. Of the 789 participants, 356 (45%) were women and 433 (55%) were men; 659 (85%) of 775 participants were White. During the study, 15 (2%) participants withdrew, primarily due to decisions related to the third vaccine dose.
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The collective evidence supports national and international COVID-19 vaccination strategies for booster vaccines to enhance both serological and humoral immune protection in susceptible populations.
The participants' anti-SARS-CoV-2 spike antibody levels were evaluated before and 21 days after the third vaccine dose. At baseline, 423 participants were identified as low responders, and after the third dose, 380 (90%) of these participants showed an increase in antibody concentrations above 400 arbitrary units (AU)/mL. However, 166 (54%) of 306 baseline nonresponders showed no antibody response after the third dose.
For T-cell responses, 616 (77%) participants had baseline and post-third dose data, with 494 (80%) showing detectable responses after their third vaccination. The third dose appeared to improve cross-reactivity to the omicron variant, though responses to this variant were lower than the wild-type.
The researchers also measured neutralizing antibody titers against various COVID-19 variants. For the wild-type variant, the median antibody concentration after the third dose was 752.5 AU/mL, a significant increase from the baseline median of 95.3 AU/mL. Similar increases were observed against the delta variant. Neutralizing responses to the omicron variant were moderate among most participants after the third dose.
Results of the logistic regression analysis suggested that previous vaccine type, age, and certain therapeutic agents significantly influenced the likelihood of a postvaccine immune response. Notably, those who previously received a 2-dose course of BNT162b2 had higher odds for an antibody response than those who received the ChAdOx1-nCov19 vaccine (odds ratio [OR], 2.0; 95% CI, 1.08-3.64; P=.029). Furthermore, participants aged at least 75 years (OR, 0.20; 95% CI, 0.06-0.58) and between 65 and 74 years (OR, 0.29; 95% CI, 0.11-0.74) had reduced odds for responding, compared with participants aged 15 to 44 years.
There were 24 serious adverse events reported among the participants who received a third vaccine dose, of which 2 were deemed vaccine-related. Overall, 7 deaths were reported during the trial. No mortalities were vaccine-related, though 2 were due to COVID-19 and 3 to underlying diseases.
Study limitations include varying cohort sizes, under-representation of participants from minority groups, and selection bias due to a modified intention-to-treat approach.
The researchers concluded, "The collective evidence supports national and international COVID-19 vaccination strategies for booster vaccines to enhance both serological and humoral immune protection in susceptible populations."
Disclosure: Some study authors reported affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors' disclosures.
This article originally appeared on Rheumatology Advisor
New COVID-19 Vaccine For Fall Should Target JN.1 Lineage, Not Variant, FDA Panel
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