People 50 and older can now get a 2nd COVID booster — here’s what you need to know

On Tuesday, the Food and Drug Administration (FDA) authorized a second booster of either Pfizer-BioNTech or Moderna’s COVID-19 vaccines for people 50 and older. The fourth shot can be administered starting at least four months after receiving the first booster with any authorized COVID vaccine.

The FDA also expanded emergency use authorization to include a second booster dose of Pfizer’s COVID vaccine for those ages 12 and older who have a compromised immune system, including individuals who have “undergone solid organ transplantation, or who are living with conditions that are considered to have an equivalent level of immunocompromise,” according to the FDA.

In addition, the FDA approved a second booster dose of Moderna’s COVID vaccine for people ages 18 and older who have a weakened immune system.

The Centers for Disease Control and Prevention (CDC) had already recommended in October 2021 that people who are immunocompromised receive a total of four doses of an authorized COVID vaccine “to stay up to date,” since they are more at risk for severe COVID and death. And just two weeks ago, Pfizer asked the FDA to approve a second booster for people 65 and older, in light of research from Israel that found people 60 and older benefited from an additional booster, which lowered rates of confirmed infections and severe illness.

This latest approval “will now make a second booster dose of these vaccines available to other populations at higher risk for severe disease, hospitalization and death,” the FDA said in a statement.

However, Dr. Kimberly Giuliano, chair of primary care pediatrics at Cleveland Clinic, who leads the clinic's vaccine distribution team, tells Yahoo Life that “the second booster still must be authorized by the CDC as well, before it will be available for the public.”

'It's important to protect these groups now'

There’s a reason why approvals for boosters — and COVID vaccines in general — have rolled out the way they have: It comes down to vulnerability. “?The additional booster is first being authorized for older adults and those who are immunocompromised, because we know that these populations are the most vulnerable to severe illness, hospitalization and death from COVID-19,” says Giuliano. “Older adults and those with compromised immune systems may not mount as high of an immune response to each injection, so their immune response can wane faster. For both of these reasons, it's important to protect these groups now.???”

However, some experts say that we don’t yet know how beneficial a second booster will be. Dr. Mahdee Sobhanie, an infectious diseases physician at the Ohio State University Wexner Medical Center, tells Yahoo Life: “Several countries have offered a fourth dose of the COVID-19 vaccine to high-risk groups, one of which are adults over the age of 50. The data which we have right now does suggest that getting a second booster is safe, but how much of an impact a second booster can have on the prevention of overall infection still remains to be seen.”

That said, Sobhanie notes people who are older or are immunocompromised are “less likely to produce a robust immune response from the two- to three-dose series,” adding: “Right now, there is data emerging that those who have risk factors to develop severe disease may benefit from a fourth shot — and a majority of these patients fall in the age category of 50 and up.”

So why do some people need an additional booster?

Namandjé N. Bumpus, director of the department of pharmacology and molecular sciences at Johns Hopkins University School of Medicine, tells Yahoo Life that both people over age 65 and those 50 and older with certain underlying medical conditions are “at increased risk for severe outcomes of COVID-19” and that “an additional booster could be beneficial, as it may provide increased protection against severe COVID-19.”

Bumpus adds: “As data emerge about the need for boosters, there is consideration of who is likely to benefit most and who could get additional protection from a dose. People most vulnerable to severe COVID-19 outcomes are most likely to benefit from an additional booster.”

That can include people who are “not immunocompromised but are at high risk for developing severe complications from COVID, such as obesity, heart disease and diabetes,” says Sobhanie, who notes that they could “potentially benefit from a fourth vaccine.”

Another factor: As with many vaccines and boosters in general, protection can eventually wane. “Data has shown that there is some reduction in protection over time with the vaccines,” says Giuliano. “A second booster dose could help increase protection, particularly against severe illness, hospitalization and death from COVID-19.”

How long does a single booster dose protect you?

Giuliano says it’s “unclear exactly” how long a single booster is protective, but says, “Current evidence suggests some protection begins to wane after approximately four months.”

However, she adds that “data show the initial booster provides much more protection against critical illness and death than just two doses alone, especially for vulnerable groups.”

Once you receive a booster, “your body does a great job producing antibodies, which can peak within a couple of months and slowly wane,” explains Sobhanie. “However, the immune system is a bit more complicated than an antibody response. It also has memory cells working in the background, [so] if you were to get COVID, your body can make antibodies to fight off infection.”

Sobhanie adds: “The thought is if you are young and healthy, and are up-to-date on your vaccine series, your body can make more of a robust antibody response than if you are older and have underlying medical conditions. This is where having a primary care provider or physician can help guide you the most on whether you should get a fourth shot or not.”

Will boosters eventually be offered to healthy people under 50?

Some experts say they will. “I think that a second booster will become available to more people at some point,” says Bumpus. However, she adds: “There is a lot more to learn about protection and who would benefit from an additional dose, as well as when they would most benefit.”

Sobhanie says there isn’t “overwhelming evidence” at this point that a second booster is necessary in individuals under the age of 50 who are up to date on their vaccine series. However, he adds, “it is possible that, with an emergence of a new variant, and based on how quickly there is spread of COVID, a booster will be necessary. But right now, it is hard to tell. I would encourage everyone who hasn’t gotten their first booster to get boosted.”

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