What’s Going on with Booster Shots?

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 efficacyOn 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.   

When Are Kids Going to Get Vaccinated?

Parents are mad.  While grown-ups have been eligible for COVID-19 vaccines for almost a year, there currently aren’t any options for children under 12.  This is especially concerning for many parents as the kids return to school amid a nationwide surge in cases.

A Different Process

On September 20, Pfizer/BioNTech released data showing its mRNA vaccine is safe and effective in children aged 5-11.  As the Food and Drug Administration (FDA) has fully approved the vaccine for individuals aged 16 and older and Pfizer/BioNTech vaccine is still available to individuals aged 12 to 15 through emergency authorization, why is the approval process taking so long for children?   

  • More data.  Earlier this year, FDA asked Pfizer/BioNTech and the other vaccine developers to provide six months of follow-up data for all clinical trial participants.  In comparison, the approval process for adults only required two months of follow-up data. 
  • More scrutiny.  Unlike the emergency use authorization (EUA) for adults, FDA doesn’t just rely on a company’s summary of the clinical trial data for children’s vaccines.  The agency looks at individual reports from every child, including data on side effects and blood tests. 
  • Biological differences.  Kids aren’t simply smaller adults.  Children have more active immune systems than grown-ups, which means scientists need to ensure they’re providing the right dosage.  Pfizer/BioNTech has specifically been testing children aged 5-11 with a two-dose regimen administered three weeks apart.  Each dose contains 10 micrograms, which is about a third of the dosage used for individuals aged 12 and up.

Pressure Grows for FDA to Speed Up Timeline

Earlier this year, it appeared that FDA would be able to approve vaccines for children aged 5-11 by early fall, just in time for the start of school.  However, signs that the approval timeline would extend first appeared in July when FDA asked Pfizer and Moderna to expand the size of their clinical trials for children to make sure they could detect potentially rare side effects, namely myocarditis, or heart inflammation.  These changes caused many health experts to revise their predictions on a timeline for approval for EUA, with some saying that the FDA would not make a decision until winter 2021 or early 2022.

The prospects of a longer timeline combined with a nationwide surge in cases sparked panic among many parents of younger children.  While COVID-19 poses a low risk for healthy kids, there is a justifiable concern about immunocompromised children as well as the ability for kids to pass the virus onto vulnerable adults.  As a result, some parents are even looking for doctors to skirt the rules and vaccinate their children, while others are signing their kids up for clinical trials, even though it’s unknown whether their child will be receiving the vaccine or a placebo.

Pressure from Pediatricians: The American Academy of Pediatrics (AAP) urged the FDA in an August 5  letter to “continue working aggressively towards authorizing safe and effective COVID-19 vaccines for children under age 12 as soon as possible” due to the threat posed by the Delta variant.  Specifically, AAP indicated that a two-month follow-up period to collect safety data is sufficient, as opposed to the six-month period FDA initially requested.  AAP also noted that reported cases of myocarditis in children who are receive mRNA vaccines like Pfizer/BioNtech’s are “extremely rare.”

The FDA is listening and took the rare step of publicly responding to the concerns around approving a COVID-19 vaccine for children on September 10. .  In addition to vowing to adhere to strict safety standards, FDA stated clinical trials are required to have a “follow-up period for safety data of at least about two months,” indicating a change from the previously requested six-month follow-up period.

The Timeline, Revised

With the FDA apparently open to a shorter follow-up period for safety data, what does the approval timeline look like now?  At the the Morgan Stanley Global Healthcare Conference 2021 on September 14, Pfizer CEO Albert Bourla laid out a new estimated approval timeline for children aged 5-11. 

  • Pfizer to have all safety and immunogenicity date in late September (topline results were released on September 20).
  • Pfizer to file for EUA in early October.
  • FDA to approve EUA within 3-6 weeks, meaning children aged 5-11 could get their shots as soon as late October or early November. 

Bourla also said Pfizer will likely have enough data on how well its vaccine works on children under 5 years of age as early as the end of October, putting that vaccine on the path for EUA by the FDA by the end of the year. 

This is reassuring news for parents of kids aged 5-11, to potentially have a vaccine available by Halloween than, say, early 2022.  But let’s not get our hopes up as COVID-19 has proven itself to be an incredibly unpredictable virus, and changing conditions could cause scientists and regulators to shift their approval considerations once again.

What’s Taking FDA So Long to Fully Approve Pfizer’s COVID-19 Vaccine?

It took the Food and Drug Administration (FDA) just three weeks to issue an emergency use authorization (EUA) for Pfizer’s COVID-19 vaccine in December 2020 when Pfizer submitted the request.  In contrast, it’s been over two months since Pfizer initiated a “rolling submission” of its biologics license application (BLA) for its vaccine on May 7, and FDA has yet to comment on its timeline for approval.  Amid growing calls for FDA to fully approve Pfizer’s vaccine, what’s making the review process take so long?

Why the Push for Full Approval?

Many people believe full approval of Pfizer’s COVID-19 vaccine will help get more shots into arms, which is seen as vital to protecting Americans from the rapidly spreading Delta variant.  According to data from the Centers for Disease Control and Prevention posted on July 6, the Delta variant makes up 51% of new COVID-19 cases in the US.  Additionally, studies show the Delta variant is at least 40% more transmissible than the Alpha variant, which was previously the country’s dominant variant.  The surge in the Delta strain comes as many Americans remain vulnerable to COVID-19, as only 67% of Americans have received at least one COVID-19 shot, and the pace of vaccinations has dropped off considerably in recent weeks. 

Full approval of the COVID-19 vaccine is one way public health experts believe could convince more Americans to roll up their sleeves, which addresses vaccine hesitancy, a sentiment echoed by several major elected officials.   In June, President Joe Biden said going from “temporary approval to full approval” would “increase the number of people” willing to get vaccinated.  Similarly, Arkansas Governor Asa Hutchinson, whose state has some of the nation’s lowest vaccination rates, remarked in June that full approval is needed to combat vaccine hesitancy.  According to a Kaiser Family Foundation poll from May 2021, 32% of unvaccinated adults said full approval of one of the currently authorized vaccines would make them more likely to get vaccinated.

Furthermore, fully approving the vaccine will allow for more businesses and organizations to mandate the COVID-19 vaccine, which could help increase vaccination rates.  While several hospitals and health systems such as Houston Methodist and Trinity Health have mandated the vaccine for their employees, some health systems like Beth Israel Leahy Health in Boston are holding off until a vaccine is fully FDA-approved.  Even though lawsuits against vaccine mandates have so far held up in court, many employers and organizations seem to be holding off on mandating  employees to get the vaccine out of fear of litigation.   Even the US Army has communicated to servicemembers that vaccination won’t be mandated until “full FDA licensure.”

What’s the Hold Up?

The reason for FDA’s longer process for fully-approving Pfizer’s COVID-19 vaccine is due to the fact that the business of issuing a BLA is more intensive than an EUA.   For an EUA to be issued, companies need to provide the FDA data that demonstrates efficacy and safety from a Phase 3 trial with a median follow-up period of at least two months.  In contrast, a BLA requires FDA to look through at least six months of clinical trial data as well as a close examination of the company’s manufacturing process, both of which take additional time.  Dr. Paul Offitt, a member of FDA’s Vaccines and Related Biological Products Advisory Committee,  commented in December 2020 that Merck’s BLA submission for its 70,000-person rotavirus vaccine trial contained enough pages to exceed the height of the Sears Tower, a 1,450-foot skyscraper in Chicago currently known as the Willis Tower.

There are benefits for drug manufacturers in getting their products fully approved.  According to former FDA Commissioner Dr. Robert Califf, a BLA would allow Pfizer to being marketing its vaccine directly to consumers.  Additionally, full approval would open the door to Pfizer increasing the price of its vaccine post-pandemic, potentially generally billions of dollars for the company.

When Will the Vaccine Be Fully Approved?

Unfortunately, FDA has yet to shed any light on its timeline for fully approving the Pfizer vaccine.  In late June, an FDA spokesperson  told The Hill that the agency “cannot comment on individual applications before it.”  More recently, the FDA told Army Times on July 2 that timelines for approval “may vary depending on a number of factors.” 

While fully approving a vaccine normally takes between 8-12 months, there is reason to believe Pfizer will receive a decision from the FDA soon. Former FDA scientist Jesse Goodman said in June that the FDA might not complete its review process for another 3-4 months, meaning a BLA might not come until  September or October.  Notably, Goodman cautions against fully approving the vaccine too quickly, as it could “undermine confidence” in the vaccine. 

Ultimately, FDA is in a tough position.  As a full review of the Pfizer vaccine continues, the agency must strike a balance between ensuring the American people can benefit from a fully approved vaccine in a timely manner without giving off the sense that the BLA was issued too quickly.  Absent any communication from FDA, however, vaccine observers have no choice but to sit and wait.

Everything You Need to Know about COVID-19 Booster Shots

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.