Pfizer and Moderna are asking the US government for permission to give fourth doses of their vaccine.
Pfizer announced last Tuesday that it had submitted an application to the US Food and Drug Administration for an additional booster dose for adults 65 years of age and older.
Albert Bourla, the CEO of Pfizer, told CBS over the weekend that Americans should prepare to get COVID-19 boosters every year, like when people line up for flu shots.
Bourla said that the protection we are getting from a third is good enough, but that the duration of the protection doesn't last very long.
Moderna said it had submitted an EUA to the FDA for the fourth dose of the vaccine. Moderna's request is larger than Pfizer's. According to the company, the EUA would allow healthcare providers to determine the appropriate use of boost among their patients, by weighing factors including a person's age and comorbidities.
Independent infectious disease experts, including some who advise the FDA on vaccines, told Insider that the move to give people in the US fourth shots might not be the most prudent idea.
Here is a quick look at the latest research and expert opinions on whether fourth doses are right for you.
Moderna and Pfizer are the only companies that still make the original vaccines, meaning they are not tailored to the fast-spreading Omicron variant or the COVID-19 variant.
The vaccines we have are based on the same virus that was discovered in January of 2020. The vaccine has not worked since the two-plus years since then.
Dr. James Hildreth, a leading infectious disease expert who advises the FDA on vaccines, told Insider that he doesn't think pharmaceutical companies should be talking about boost with the same vaccines that we have.
Hildreth is worried that by using shots that are tailored to a 2-year-old virus, we might create new problems. If you boost with an out-of-date shot, you could be producing less value against circulating viral strains. There is a chance that the virus could learn to develop better resistance to the vaccines. The older version of the virus could benefit from more frequent boosts.
Hildreth said that there was evidence from studies in mice that repeated immunizations, with the intervals too short, could induce tolerance.
One big problem with modifying the existing vaccines is that it is not clear what kind of FDA review would be required before it could be given out. Several independent research groups and pharmaceutical companies are working on pan-coronaviruses vaccines that would target different coronaviruses at once, hoping to achieve broad immune protection against future coronaviruses that aren't even in circulation yet. The pan-coronaviruses vaccines are at least a few years away.
The data we have so far suggests that older people and those with underlying medical conditions will derive good benefits from fourth doses. There isn't a lot of data that shows booster shots benefit younger immune systems.
According to a recent CDC study, vaccine effectiveness against severe outcomes, such as mechanical ventilation and death during the peak of the Omicron wave in early January, was 81% with two shots and 94% with three, suggesting a booster shot provides only marginal improvement in vaccine effectiveness for most people. A CDC study shows that more than 98% of people who were hospitalized with COVID had preconditions, and the same was true for 9 out of 10 people who were boosted.
Moderna executives agree that the most vulnerable patients should be the focus of additional booster programs.
For those who have cancer, Caval can be a life-threatening disease, even post-vaccine, but he said additional boosts aren't necessarily needed for members of the general public under 65.
Israel has already tried out the fourth dose of Pfizer and Moderna's vaccines on young, healthy populations and only got mediocre results. A study of more than 1,000 Israeli healthcare workers who were given fourth shots four months after their initial boost suggested there was no additional boost to the immune system. There was only a marginal benefit to giving young, healthy populations another jab, as a fourth dose temporarily increased antibody levels to where they were after a third shot.
Dr. Barney Graham, one of the co-inventors of Moderna's COVID-19 vaccine, told Insider that the vaccines provide protection from severe disease.
He said that part of how the vaccines work is to protect the lower airway and upper airway from disease.
A recent study of more than 422,000 people across the US who took Johnson and Johnson's single-shot vaccine suggested that it has been working well at preventing hospitalizations and deaths, though that finding was slightly less true among the most vulnerable patients.
Hildreth said to identify those who are most vulnerable and make sure they are protected.
Graham says more shots should be sent to the bottom half of the globe, rather than considering fourth doses for large swaths of those who are already inoculated in the US this summer. He's worried that COVID-19 could spread fast there, as temperatures tumble, and that may give rise to a concerning new variant that could escape all of our current vaccines.
He asked if we could just get the Southern Hemisphere vaccine before June.
The reason we have had to deal with variant is that we didn't get the world immunized fast enough.
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