Should I Be Immunized, and When? A COVID-19 Booster Update

This transcript has been edited for clarity.

Hello. I’m Paul Auwaerter with Medscape Infectious Diseases. I thought an update about COVID-19 boosters would be useful, especially since the Food and Drug Administration has now given emergency use authorization to newly formulated bivalent vaccines for SARS-CoV-2, incorporating BA.4 and BA.5 components along with the initial strain of SARS-CoV-2. This is the first reformulation since the advent of the vaccines in December 2020.

First, I have to say that it’s really remarkable that manufacturers and regulatory agencies have given a nod and produced a vaccine that’s ready for distribution, with these subvariants only really emerging this spring; so in the space of 4 or so months, they have been able to produce a new vaccine. This is about as fast as influenza, in this case. It just shows how this mRNA technology can be changed rather quickly.

Now, there’s been considerable debate about whether a revamped vaccine is necessary. BA.5 is still circulating and providing most of the sequenced infections that have been analyzed, and seems to have plateaued, but we’ve been surprised before. Novel variants or subvariants have emerged that have some increasing immune invasiveness. There’s certainly a strain of thought that updating the vaccine would be useful.

On the other hand, some proponents of sticking with the original set of vaccines point out that people who are boosted, especially if they’re in higher-risk groups and are fully up-to-date with two boosters, are very well protected against landing in the hospital and experiencing severe COVID-19 or death. What we’re seeing, of course, is still people in the hospital and people dying of COVID-19, but they often have significant health problems, comorbidities, are elderly, or are not immunized.

Certainly, when patients ask me, “Should I get immunized, and when?” I’ll first ask if they’ve ever had a booster, and if not, that’s probably the first priority. Of course, many people have been holding out for this updated vaccine and will probably be getting it in conjunction with influenza immunization.

I’d still say it’s important, as we don’t know what this respiratory season will hold. Some modelers suggest that it could be another bad season, just like Omicron was last winter. If you’ve only had a primary series, or only one booster and you’re in the higher-risk groups whose time has passed, it’s important to go ahead and get that first or second booster.

For these new boosters, the one from Pfizer is approved for ages 12 and higher, and the one from Moderna is for ages 18 and older. You can get them 2 months from your primary series or your last booster. People would qualify in these age groups.

We do know from a number of studies that boosting does give some short-term advantages. We know that, especially against the BA.4 and BA.5 strains, immunization does help protect against infection with improved efficacy. A number of studies have shown this. How long this lasts is not as clear, and of course, those data will be forthcoming over time.

The other news is that there is a new vaccine, the Novavax vaccine, which is a protein subunit booster that has emergency use approval. There is not yet a Novavax booster available, although that application is in front of the FDA.

Patients have heard and asked about a bivalent SARS-CoV-2 and influenza vaccine. Indeed, Novavax has completed a phase 1 trial. They are in the phase 2 portion of this and that is well tolerated and immunogenic, but I don’t believe that it will be ready for this respiratory season.

The focus will clearly be on the vaccines from Pfizer and Moderna for boosters. How this will be distributed and how fast it will be in pharmacies is likely soon.

I fear that there is certainly some vaccine and pandemic fatigue, but I think it’s important to motivate our patients, even if they’ve been immunized or have experienced COVID-19 illness itself.

For those at highest risk — that is, people who are over 65 years old and certainly over 75 years old or have significant health problems — I feel that the insurance of an extra booster is probably worthwhile, especially if some considerable time has passed since their last vaccine, which could be last year or last winter.

Thanks so much for listening.

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