How long does immunity from the new COVID bivalent boosters last ‘in the real world’? – San Francisco Chronicle

Dear Advice Team: Do medical experts have any idea yet how long immunity from the bivalent COVID booster will last? I know that previous boosters showed waning immunity over time, and Im wondering what this means for vulnerability around the holidays. Also, are there any rumblings about if/when the next round of boosters will be available?

Welcome to Pandemic Problems, an advice column that aims to help Bay Area residents solve their pandemic and post-pandemic conundrums personal, practical or professional. As COVID evolves into an endemic disease, we know readers are trying to navigate the new normal. Send your questions and issues to pandemicproblems@sfchronicle.com.

Todays question is fielded by The Chronicles Anna Buchmann.

Dear Reader: Your questions about the new COVID-19 vaccine boosters are very timely. We are just six weeks into the rollout of the bivalent shots so-called because they target two coronavirus strains, the ancestral version plus the BA.4 and BA.5 omicron subvariants currently circulating and as you note, many of us are making holiday plans that involve travel and gathering with others.

Meanwhile, bivalent booster eligibility has already expanded to include younger children as of Wednesday, everyone ages 5 and up may receive one dose of Pfizers bivalent mRNA booster (for the Moderna version, its 6 and up) at least two months after completing their primary vaccine series or at least two months after their last dose of the original monovalent booster.

Health officials are urging people to get the new boosters to help head off a potential winter COVID-19 surge, with Centers for Disease Control and Prevention data showing less than 6% of eligible people had gotten the bivalent shot as of Monday. The CDC now says you are up to date on COVID vaccination after receiving a primary series and the most recent booster dose recommended.

With that context, your first question was about the immunity we get from the bivalent booster and how long it lasts.

Compared with the original booster, the bivalent boosters nearly double the levels of antibodies that can prevent omicron from infecting cells, according to Dr. Nadia Roan, a UCSF immunologist and investigator at the Gladstone Institutes. But in the real world, its not currently clear how much more protective the bivalent booster is, she said via email.

As for immunity duration, if BA.4 and BA.5 stay dominant, the new booster could give excellent protection against even a mild infection for four to six months, UCSF infectious disease expert Dr. Peter Chin-Hong said in an email. However, if more immune-evasive variants gain a greater foothold, the booster could grant maximum protection for about two to four months, decent protection for about four to six months, and less protection after six months, he said.

Both Roan and Chin-Hong agreed that those up to date on their vaccinations will have long-lived protection against serious disease and death from COVID perhaps more than a year without further boosters, Chin-Hong said.

You asked specifically about the holiday season. By that time, those who received the bivalent booster at the start of the rollout can expect full protection against serious disease and death for sure and likely substantial protection against even a mild infection for that time period provided the variant mix (all flavors of omicron) stays similar, Chin-Hong said.

If you have not had COVID or received one of the original boosters in the past few months, I would suggest getting the bivalent soon, Roan said. Thats because after boosting, antibody levels spike in about a week and stay elevated before declining steadily, she said. Those antibodies decrease your chances of infection.

So if you wanted (to) maximize protection for the holiday season, it could be timed 2-3 weeks before then, she said.

Chin-Hongs advice was to get the bivalent booster by Halloween.

Not only will it make you more confident about trick-or-treating, you will optimize your protection against infection for when we expect cases to increase, he said.

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Full protection will kick in within two weeks, he said. This will increase your chances of not missing Thanksgiving dinner, that family reunion or long-awaited vacation trip.

Your final question was about a possible next round of boosters. Both Roan and Chin-Hong said they had not yet heard any discussion on that front, though Chin-Hong said its possible we may get updated COVID boosters annually, like the flu vaccine.

Any reformulation of the boosters for next winter, possibly by September 2023, would depend on what happens with variants, Chin-Hong said. If omicron continues to dominate, the formula might not change.

But it is very likely that COVID will continue to mutate, he said.

Pandemic Problems is written by Chronicle Advice Team members Annie Vainshtein, Kellie Hwang and Anna Buchmann, combining thorough reporting and guidance from Bay Area experts to help get answers and find a way forward.

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How long does immunity from the new COVID bivalent boosters last 'in the real world'? - San Francisco Chronicle