Is the new Covid-19 booster for you? Our medical analyst explains

(CNN) Is it time for another Covid-19 vaccine booster? That’s the question many are asking their doctors, given what happened last week – the US Food and Drug Administration changed its authorization to allow a second bivalent booster for certain individuals most vulnerable to severe outcomes from Covid-19. The US Centers for Disease Control and Prevention subsequently signed off on the FDA’s update and added additional clinical considerations to guide healthcare providers and patients.

I have many questions. Who is eligible for the second bivalent booster? Is the composition of the booster the same as before? If someone receives the booster now, can they get another booster in the fall? What if someone is not in one of these high-risk groups, but lives with a high-risk family member? And how has the guidance changed for people who haven’t had their first booster yet and those who are still unvaccinated?

To track down some answers, I reached out to CNN medical analyst Dr. Leana Wen. Wen is an emergency physician and professor of health policy and management at the George Washington University Milken Institute School of Public Health. She previously served as Baltimore’s health commissioner.

CNN: Can you bring us up to date with the big updates — who is now eligible to receive the other bivalent booster?

Dr AS Leana Wen: There are two groups that can now receive a second bivalent booster.

Firstly, there are people aged 65 and over. Since very early in the pandemic, we have known that older individuals are among those most exposed to serious outcomes from Covid-19. These people are newly eligible to receive their second bivalent booster if at least 4 months have passed since their first bivalent shot.

Second, there are immunocompromised people. The new guidance from the CDC is that anyone age 6 and older with moderate or severe immunocompromise can get another bivalent booster if at least two months have passed since the first. They should also consult with their doctors; depending on their specific medical circumstances, they may be able to receive the bivalent booster as often as every two months.

CNN: Is the composition of the booster the same as before?

Wen: The bivalent booster I’m referring to is the updated booster that first became available in fall 2022, which targets both the original strain of the coronavirus and the BA.4/BA.5 omicron subvariants. Studies have shown that this booster continues to be effective against common circulating strains when it comes to important metrics for reducing serious illness. Those who were recently eligible for their second shot would receive this bivalent booster again. There is no option to select the original monovalent image and no other type of booster is available.

CNN: If someone receives the booster now, can they get another booster in the fall?

Wen: It is possible that there will be an updated version of the booster available during the autumn that more specifically targets dominant variants in circulation. The people newly eligible to receive the second bivalent booster are vulnerable people who will almost certainly be the same first groups eligible to receive a new Covid-19 vaccine in the fall. All of this is to say that people should not be dissuaded from getting a booster now thinking it will rule them out of another vaccine later.

CNN: What if someone is not in one of these high-risk groups, but lives with a high-risk family member?

Wen: That person would not be eligible himself. The Covid-19 vaccines are very good at reducing the risk of hospitalization and death for the person being vaccinated. For a short time, it reduces the risk of infection, but that effect is muted and transient. Federal health officials have not authorized family members or caregivers of high-risk individuals to receive the second bivalent booster, and I believe this is the right decision based on scientific evidence.

There are other ways to reduce the risk of getting Covid-19 and spreading it to someone close to you. These methods include regular testing, especially when symptomatic or after exposure to an infected person, and wearing a high-quality mask in crowded indoor spaces.

CNN: How has guidance changed for people who haven’t had their first booster yet and those who are still unvaccinated?

Wen: It has actually changed quite a bit. The CDC aims to simplify vaccine recommendations and made several important changes.

Initially, the bivalent vaccine will be the only vaccine made available. The original monovalent vaccine will no longer be used, even in people who have not yet been vaccinated. This will help to simplify vaccine administration, as pharmacies no longer need to have both types of vaccine in stock.

In addition, unvaccinated persons 6 years and older will be considered up-to-date on vaccines if they received only one dose of either Pfizer-BioNTech or Moderna bivalent booster. The idea here is that most unvaccinated people in this age group have already had Covid-19, and one dose of the updated booster is sufficient to provide extra protection.

People who have received previous vaccines against coronavirus will still need at least one dose of the bivalent booster to be considered up-to-date. That is, even if an individual received three or more doses of the original monovalent vaccines, they are still not considered up-to-date unless they received at least one bivalent dose. This is an important point, as CDC data show that fewer than one in five people eligible to receive the first bivalent dose have received it; that means, according to their new definition, less than one in five Americans previously considered fully vaccinated are actually up to date on their Covid-19 vaccines.

CNN: What’s the bottom line — should people who are newly eligible for boosters do it right away?

Wen: I think newly qualified people should talk to their doctors about what is right for them. The CDC issued what’s called a permissive recommendation, meaning people can choose to get the extra booster if they want. A generally healthy 65-year-old who recently had Covid-19 could choose to wait until the autumn to get a new booster. But an 89-year-old with kidney disease and a history of strokes and heart attacks, and who is not eligible to take the antiviral treatment Paxlovid, may want every possible level of protection, including with the extra booster.

In my view, this permissive approach to additional boosters is in line with where we are at this point in the Covid-19 pandemic: people should choose the level of protection that is most appropriate for them, based on their individual medical circumstances.