FDA

Will We Need More Booster Shots?

by Matt Gontarchick

People will only need annual COVID-19 booster shots after getting their third vaccine dose, according to a top Food and Drug Administration (FDA) official at the 2022 Innovation in Regulatory Science Summit in January 2022.  Since then, however, mounting evidence over waning immunity plus the potential of a new wave of COVID-19 are feeding calls for people to get their fourth vaccine doses sooner rather than later.  Does that mean Americans can expect to get a second booster shot in the coming months?

First, some Americans are already able to get a second booster shot.  According to guidance from the Centers for Disease Control and Prevention (CDC), people ages 12 years and older who are moderately or severely immunocompromised should receive a total of four mRNA vaccine doses.  This includes transplant patients and those undergoing chemotherapy for cancer.

Drug manufacturers are already asking for approval on second boosters for additional populations.  In mid-March, Pfizer and Moderna submitted applications to the FDA for an emergency use authorization (EUA) for a second booster dose of their respective COVID-19 vaccines.  While Pfizer is specifically seeking an EUA for adults over age 65, Moderna is requesting an EUA for anyone over 18 years of age. 

The submission of both applications came just days after Pfizer CEO Albert Bourla said a fourth vaccine dose will probably be needed for everyone.

  • One reason for this is mounting data that shows protection acquired from a third COVID-19 vaccine dose wanes over time.  According to CDC data, a booster shot’s effectiveness in protecting against hospitalization dropped from 91% to 78% between August 2021 and January 2022 – a timeframe that includes both the Delta and Omicron variants. 
  • Another reason for a fourth shot is a need to protect Americans ahead of a new wave of COVID-19 cases.  In recent weeks, a new Omicron subvariant known as BA.2 has driven an increase in cases across Europe, which many experts say could foreshadow an increase in cases in the US within the coming weeks.  Although BA.2 is roughly 30% more transmissible than the original Omicron strain, it does not appear to be more severe or lead to more hospitalizations.  While overall COVID-19 case numbers are still trending downward in the US, 10 states have reported an increase in case numbers over the last 14 days. 

Due to these concerns over waning immunity and growing case numbers, nearly a dozen countries including Australia, Belgium, Denmark, Israel, Poland, Sweden, and the United Kingdom have already begun offering fourth doses, albeit eligibility is limited to seniors and medically vulnerable people in most cases.  Additionally, reports suggest the FDA could authorize second boosters for all adults over age 50 as soon as March 29.  However, that doesn’t necessarily mean the government will follow suit in recommending a fourth mRNA vaccine dose to every individual age 12 and up who’s already cleared to get a third dose anytime soon, as a couple issues stand in the way.  These include:   

  • Regulatory approval.  The FDA’s vaccine advisory committee will meet on April 6 to discuss the need for additional COVID-19 booster shots.  However, the advisory panel will NOT be reviewing any EUA applications from Pfizer or Moderna or taking a vote on recommendations – instead, the committee will discuss the timing and populations for additional doses in the coming months.  The April 6 agenda is a sign of the federal government’s cautious approach to boosters, which means it might take some time for federal regulators to sign off on additional doses, especially for the broader population.  In September 2021, for instance, a CDC advisory panel declined to recommend third doses for people who work in “high-risk” settings like health care practitioners and teachers – a decision which was ultimately overruled by CDC Director Rochelle Walensky.
  • Data.  Even though a number of countries have already cleared fourth shots for certain populations, the jury’s still out on whether a second booster will make a difference for non-elderly adults who are not considered medically vulnerable.  Preliminary results from a study involving 154 health care workers in Israel found that a fourth mRNA dose is only “partially effective” in protecting against the Omicron variant.  Without any strong evidence of the effectiveness of a fourth shot, US regulators are likely to continue to take a cautious approach on recommending additional boosters for the broader population.
  • Funding.  Lawmakers dropped $15 billion in additional COVID-19 funding from the Fiscal Year (FY) 2022 omnibus appropriations bill, and so far, congressional leaders are locked in a stalemate on passing separate legislation on additional COVID-19 support.  Without additional funding, Biden administration officials have warned that they won’t have enough money to purchase a potential fourth vaccine dose for even 70% of all Americans.  And barring additional funding, the federal government will no longer be able to cover the cost of vaccinations for uninsured people starting on April 5, which means uninsured immunocompromised Americans may not be able to afford a booster if they need one.

Ultimately, the trajectory of the COVID-19 pandemic may ultimately inform whether additional boosters are necessary for Americans, and in turn, whether Congress decides to allocate enough money to pay for additional vaccine doses.  While White House Chief Medical Advisor Anthony Fauci has acknowledged that the BA.2 subvariant is likely to cause cases to rise in the US, he doesn’t anticipate new cases will culminate in a major surge that results in high levels of hospitalizations. 

Indeed, a good portion of the US population has acquired some degree of immunity through infection, vaccination, or both over the last two years of the pandemic, which could protect Americas from the worst consequences if case numbers continue to rise over the next few weeks.  However, if hospitalizations suddenly spike across multiple populations, it may be too late for the federal government to act swiftly on additional boosters.

Administration

What’s Going on with Booster Shots?

by Matt Gontarchick

There’s been a lot of discussion about COVID-19 booster shots lately – so much so, that it’s hard to keep track of who can get booster shots and what kind of booster shots are available.  Here, we provide a lay of the land on booster shots.

Why are booster shots necessary?  Booster shots provide an extra “boost” to immunity through an additional dose that cues the immune system to produce a stronger antibody response.  While all three currently approved vaccines from Pfizer, Moderna, and Johnson & Johnson are highly effective in protecting against hospitalization and death, a growing number of studies show that vaccine efficacy gradually wanes over time. 

Who can get booster shots now?  Pfizer’s COVID-19 vaccine is the only vaccine that is currently authorized by the Food and Drug Administration (FDA) to be used as a booster dose.  The FDA formally amended the emergency authorization use (EUA) for the Pfizer vaccine on September 22.  According to the amended EUA, the following people are eligible for booster shots at least six months after their initial series of shots:

  • People over age 65.
  • People ages 18 to 64 at high risk of severe COVID-19 due to chronic medical conditions or compromised immune systems.
  • People with greater risk of workplace exposure, such as frontline medical workers, teachers, and emergency responders.

More booster shots are on the way.  The FDA Vaccines and Related Biological Products Advisory Committee (VRBPAC) voted during an October 14-15 public meeting to recommend booster doses from Moderna and Johnson & Johnson. The panel recommended the Moderna booster be administered under the same criteria as Pfizer’s – six months after the second dose for people over 65, individuals at risk for serious complication from COVID-19, and essential workers.  However, the panel recommended broader criteria for the Johnson & Johnson booster – it said anyone who received the single dose Johnson & Johnson vaccine should be eligible to receive a second booster dose at least two months later. 

  • Why? Several studies have shown the Johnson & Johnson vaccine is less effective that other currently approved shots, particularly against new variants like Delta.

What happens next: The CDC Advisory Committee on Immunization Practices (ACIP) will meet on October 20-21 to offer its recommendations on who should get the Moderna and Johnson & Johnson booster shots.  Its recommendations are subject to a final decision from the CDC director.  Afterwards, the FDA could officially authorize booster shots from both companies in the following days. 

The conversation on booster shots hasn’t been without controversy.  Over the past few months, scientists, researchers, and public health officials within the federal government haven’t seen eye-to-eye on when booster shots should become available, and who should get them. 

  • For example, CDC Director Rochelle Walensky partially overruled ACIP last month when the panel initially declined to offer booster shots for essential workers under 65 who do not have chronic medical conditions.  Some ACIP members said that without additional data, they weren’t comfortable automatically allowing younger people to get boosters just because of their jobs.  While Walensky acknowledged the panel’s uncertainty, she said in a statement that CDC must use “imperfect data” to “take actions that we anticipate will do the greatest good.”
  • There are also ethical considerations as billions worldwide remain unvaccinated.  While many public health experts believe people with chronic health conditions should get additional shots, they feel extra doses should be allocated to countries with low vaccination rates first in order to prevent more dangerous variants from developing. 

The administration’s internal disputes have been quite apparent to the public.  Back in August, President Biden announced a plan to start distributing booster shots to all eligible Americans as soon as September 20.  However, the health care agencies tasked with rolling out boosters have taken a more conservative approach, and one month later after Biden’s original deadline, only certain segments of the population have access to one vaccine booster.   

With limited information and uncertainty about the future of the virus, administration officials are between a rock and a hard place.  On one hand, federal officials don’t have enough data to make definitive decisions on who needs a booster and how much a booster would improve efficacy.  On the other hand, the administration knows it can’t wait for definitive findings to become available, especially if case number surge once again in the next few months as colder temperatures drive more Americans indoors.

At the end of the day, COVID-19 is still a novel virus, and there are many unanswered questions on how long protection from vaccines last and how much that protection varies between different groups of people.  While new data on vaccines will continue to gradually become available, federal health officials will have to continue discussing and weighing the risks and benefits of authorizing vaccines in the US.   

FDA

Everything You Need to Know about COVID-19 Booster Shots

by Matt Gontarchick

Every year, you get your flu shot.  Will the same be said for COVID-19 shots?  No one knows for sure, but federal officials and public health experts are weighing in on whether certain people might need COVID-19 booster shots as soon as this fall.  With questions about the longevity of vaccine-induced immunity and the potential for vaccine-eluding variants still unanswered, it certainly does not hurt to prepare.

What Is the Administration Planning?

On May 11, David Kessler, MD, Chief Science Officer of the White House COVID-19 Response Team, told a Senate panel that the Biden Administration is preparing for the possibility of booster shots for people who do not have a robust or long-lasting immunity, or if new variants evade protection from previously-administered vaccines.  Kessler said the booster shots would likely be a third shot of Pfizer or Modern’s mRNA vaccine rather than a new shot tailored to emerging variants.  He also confirmed that the booster shots would be free to Americans and funded by congressional appropriations through the end of Fiscal Year (FY) 2021.  Since Kessler’s testimony, the Administration purchased 200 million additional doses of Moderna’s COVID-19 vaccine in June to vaccinate children or to serve as a booster shot for adults.  Any decision to use booster shots would be up to the Food and Drug Administration (FDA) and the Centers for Disease Control and Prevention (CDC).

Kessler’s testimony was not the first time someone raised the possibility that people vaccinated against COVID-19 could need booster shots in the future.  In February, Johnson & Johnson CEO Alex Gorsky said COVID-19 booster shots may be needed annually, like flu shots.  Similarly, Pfizer CEO Albert Bourla said in April that people will likely need a third dose of a COVID-19 vaccine within 12 months of being fully vaccinated. 

How Long Does Immunity from Vaccines Last?

Since the vaccines were just developed in 2020, experts say only time will tell how long protection from the vaccines will last.  Of the few studies conducted so far, research from the New England Journal of Medicine published in April 2021 found Moderna’s COVID-19 vaccine can produce strong antibody protection for at least six months following the second dose.  Pfizer also announced research findings in April confirming its vaccine’s efficacy six months after the second dose.  

However, new research suggests it could be for a year or longer.  A pair of studies published in May 2021 found that the B-cells of people infected with COVID-19 still continued to mature and strengthen one year after infection, suggesting some type of immune response.  More recently, a study published in the journal Nature in June suggested immunity from mRNA vaccines could last for years.

What about the Variants?

However, many of these studies were conducted before the Delta variant became more prevalent.  Public health experts say the Delta variant, which was first discovered in India in October 2020, is 43-90% more transmissible than previous COVID-19 variants, leading some to believe that currently-approved vaccine are less efficacious against the  Delta variant.  A recent study said the Delta variant could become dominant in the US by mid-July.

Fortunately, the vaccines still offer strong protection.  According to a study by Oxford University researchers, two doses of the Pfizer vaccine appears to provide 79% protection against the Delta variant, compared to 92% against the Alpha variant, which is currently the dominant variant in the US, and was first discovered in the United Kingdom in September 2020.  Since the Moderna vaccine uses the same mRNA technology as Pfizer’s, it can be inferred that two Moderna doses offer the same levels of protection as the Pfizer vaccine provides against the Delta variant. 

But what about the Johnson & Johnson vaccine?  Compared to its Moderna and Pfizer counterparts, the single-dose vaccine has been administered far less, meaning public health officials have little data regarding its effectiveness against the Delta variant.  However, experts say a Johnson & Johnson vaccine is better than no vaccine at all, and that one dose is likely effective at protecting a recipient against serious illness or death.  Additionally, former Senior Advisor to the COVID-19 Response Coordinator Andy Slavitt has said that recipients of the Johnson & Johnson could take a single mRNA booster shot now for added protection.

Nonetheless, just because the current vaccines remain effective against the Delta variant does not  mean they are  necessarily guaranteed to be effective against future variants.  As explained by CDC Director Rochelle Walensky on June 22, the Delta variant represents a “set of mutations” of COVID-19, and future mutations could produce a variant that evades protection from vaccines.  However, scientists say it’s unlikely a variant will arise that will make COVID-19 vaccines totally unless.  While vaccines appear to offer diminishing protection from being infected from newer COVID-19 variants, they still appear effective at preventing hospitalization and death.    

The Jury Is Still Out

The point of vaccines is to protect people from serious illness and death, and until fully vaccinated individuals are finding themselves with infections severe enough to require hospitalization, is it difficult to predict when booster shots will be needed and how often.  In an interview on May 21, National Institute of Allergy and Infectious Diseases Director Dr. Anthony Fauci said the need for booster shots is still unclear.  The CDC Advisory Committee on Immunization Practices reached a similar conclusion on June 24, saying there currently is not enough data to determine booster shots are needed, although the panel did not rule out the possibility of requiring booster shots if immunity wanes or new variants render existing vaccines less effective.  Considering this risk, the evolving nature of the virus, and the pain the world has already experienced at the hand of COVID-19, the US government has every reason to prepare for the worst and continue this conversation around COVID-19 booster shots.