Outside the Beltway

New and Improved COVID Vaccines

Pfizer and Moderna will soon roll out protection against newer strains.

James Joyner · Sunday, August 28, 2022 · 5 comments

The Atlantic‘s Rachel Gutman-Wei offers “A Simple Rule for Planning Your Fall Booster Shot.”

In less than two weeks, you could walk out of a pharmacy with a next-generation COVID booster in your arm. Just a few days ago, the Biden administration indicated that the first updated COVID-19 vaccines would be available shortly after Labor Day to Americans 12 and older who have already had their primary series. Unlike the shots the U.S. has now, the new doses from Pfizer and Moderna will be bivalent, which means they’ll contain genetic material based both on the ancestral strain of the coronavirus and on two newer Omicron subvariants that are circulating in the U.S.

These shots’ new formulation promises some level of protection that simply hasn’t been possible with the original vaccines. “A bivalent vaccine will have some benefit for almost everybody who gets it,” Rishi Goel, an immunologist at the University of Pennsylvania, told me. “How much benefit that is, we’re still not exactly sure.” People who aren’t at high risk could end up only marginally more protected against severe outcomes, and no one thinks the shots will banish COVID infections for good. There is, however, a simple rule of thumb that nearly everyone can follow to maximize the uncertain gains from a shot: Wait three to six months from your last COVID infection or vaccination.

Everyone in my household save for my youngest daughter, who just turned 11, is both eligible and in this window. My oldest stepdaughter, who’s been on her own for about a year, is the only one (at least that we know of) who has had COVID—just last month, so not yet ready.

Put that rule into action, and it plays out a little differently, depending on your circumstances.

If you haven’t had COVID since about November 2021, the advantage of a bivalent booster over the original formula is obvious, and as long as you haven’t gotten boosted recently, there’s every reason to get the new one right away. (If you have been boosted in the past few months, your antibody levels are probably still too high for a new shot to do much for you.) Marion Pepper, an immunologist at the University of Washington, told me that Americans who have already gotten three or more doses “have probably maxed out the protective capacity” of the original shots. By contrast, the bivalent vaccines offer something new to those who have so far escaped Omicron: a lesson on the spike proteins of the BA.4 and BA.5 subvariants, which will help the immune system fight the real thing should it get into your body. “I’m just super excited to get the bivalent vaccine,” says Jenna Guthmiller, an immunologist at the University of Colorado who has not yet had COVID. “I think it’ll be really nice and ease my mind a little bit.”

Because I’m not in a high-risk category and because I experience a fairly significant adverse reaction to the shots, I opted not to get the second booster shot even though, as an over-50, I was eligible. And, indeed, if Pepper is right, it wouldn’t have done me much good, anyway. I’ll almost certainly get this shot, though, as soon as it’s convenient to get an appointment. (I imagine it’ll be relatively hard in September.)

It’s not a slam dunk, though:

Veterans of Omicron infections might still have something to gain from seeing the BA.4 and BA.5 spike proteins—especially if your goal is to avoid getting sick with COVID at all. Past a certain number of shots, boosters’ impact on your long-term protection against severe disease is unclear, Goel told me. Paul Offit, the director of the Vaccine Education Center at Children’s Hospital of Philadelphia, told me he doesn’t plan on getting a booster at all this fall because, after three vaccine doses and an infection, “I think I’m protected against serious illness.” But if you want to stave off infection, Goel said, “the bivalent vaccines, or really any variant-containing vaccines, have real value.” That’s because formulas based on a given variant have been shown to temporarily increase your stock of antibodies that target that variant.

How long that extra-protective state lasts, or whether it’s sufficient to prevent any infection whatsoever, is still a scientific puzzle. The original boosters were shown to increase antibody levels to a peak about two weeks after the shot, then decay steadily over the following three months. We don’t know yet whether a bivalent formula will change that timeline, Goel said.

But you can still use it to estimate approximately when your protection will be at its highest. You might, for example, choose to err on the early side of that three-to-six-month timeline if you have a particularly high-risk event coming up in the next few weeks. “If all we had was the original booster and I was going to an indoor wedding or something, I think it would be reasonable to get that booster,” Pepper said.

Again, so far as I know, I haven’t had any of the COVID variants. But an updated vaccine seems more worth the likelihood of being sick for a day or two than another jab of the original.