COVID-19 vaccine makers are studying updated boosters that
might be offered in the fall to better protect people against future
coronavirus surges.
Moderna’s preliminary study results show people given the
combination shot experienced a higher boost in omicron-fighting antibodies than
if they just got a fourth dose of the original vaccine.
“We believe strongly that this data supports an update of
the vaccine,” Dr. Stephen Hoge, Moderna’s president, said Wednesday.
Today’s COVID-19 vaccines all are based on the original
version of the coronavirus. They’re still providing strong protection against
severe disease, hospitalization and death even after the appearance of the
super-contagious omicron variant -- especially if people have had an initial
booster dose.
But the virus continues to mutate rapidly in ways that let
it evade some of the vaccines’ protections and cause milder infections.
So U.S. regulators, and the World Health Organization, are
considering whether to order a change in the vaccine recipe for a new round of
booster shots in the fall -- when cold weather and kids returning to school are
expected to drive yet another surge.
Key questions: How to make that change without losing the
continued strong protection against COVID-19’s worst outcomes? And what’s the
right variant to target? After the huge winter omicron surge, that mutant’s
genetically distinct relatives now are the main threats, including one that’s
fueling the current U.S. wave of infections.
The Food and Drug Administration has set a meeting in late
June for its scientific advisers to debate those questions and evaluate data
from vaccine makers’ tests of potential new formulas. Pfizer also is studying a
combination shot, what scientists call a bivalent vaccine, with some data
expected later this month.
Moderna’s new study tested people who’d had three prior
vaccinations, giving 377 of them a fourth dose of the original vaccine and
another 437 the combo shot.
The study wasn’t designed to track how well the updated
booster prevented COVID-19 cases and it was tested only against omicron, not
the variants dominant now. But the bivalent vaccine sparked a nearly eight-fold
rise in levels of antibodies capable of fighting omicron. Importantly, that was
1.75 times better than the antibody jump from simply giving a fourth dose of
the original vaccine, Moderna said.
The data hasn’t undergone scientific review, and these
initial measurements were taken a month after booster shots. Antibodies
naturally wane so it’s not clear how long that protection could last. Moderna
plans to track the levels at three and six months but already is manufacturing
doses to be ready if regulators in the U.S. or elsewhere order a change for
fall shots.