The Columbus Dispatch

Vaccine makers racing to update shots

Preparatio­ns being made in case omicron variant forces drastic changes

- Lauran Neergaard

Vaccine makers are racing to update their COVID-19 shots against the newest coronaviru­s threat even before it’s clear a change is needed, just in case.

Experts doubt today’s shots will become useless but say it’s critical to see how fast companies could produce a reformulat­ed dose and prove it works – because whatever happens with omicron, this newest mutant won’t be the last.

Omicron “is pulling the fire alarm. Whether it turns out to be a false alarm, it would be really good to know if we can actually do this – get a new vaccine rolled out and be ready,” said immunologi­st E. John Wherry of the University of Pennsylvan­ia.

It’s too soon to know how vaccines will hold up against omicron. The first hints this week were mixed: Preliminar­y lab tests suggest two Pfizer doses may not prevent an omicron infection but they could protect against severe illness. And a booster shot may rev up immunity enough to do both.

Better answers are expected in the coming weeks and regulators in the U.S. and other countries are keeping a close watch. The World Health Organizati­on has appointed an independen­t scientific panel to advise on whether the shots need reformulat­ing because of omicron or any other mutant.

But authoritie­s haven’t laid out what would trigger such a drastic step: If vaccine immunity against serious illness drops, or if a new mutant merely spreads faster?

“This is not trivial,” Biontech CEO Ugur Sahin, Pfizer’s vaccine partner, said shortly before omicron’s discovery. A company could apply to market a new formula “but what happens if another company makes another proposal with another variant? We don’t have an agreed strategy.”

It’s a tough decision – and the virus moves faster than science. Just this fall

the U.S. government’s vaccine advisers wondered why boosters weren’t retooled to target the extra-contagious delta variant – only to have the next scary mutant, omicron, be neither a delta descendant nor a very close cousin.

If vaccines do need tweaking, there’s still another question: Should there be a separate omicron booster or a combinatio­n shot? And if it’s a combo, should it target the original strain along with omicron, or the currently dominant delta variant plus omicron? Here’s what we know.

Companies aren’t starting from scratch

COVID-19 vaccines work by triggering production of antibodies that recognize and attack the spike protein that coats the coronaviru­s, and many are made with new technology flexible enough for easy updating. The Pfizer and Moderna vaccines are fastest to tweak, made with genetic instructio­ns that tell the body to make harmless copies of the spike protein – and that messenger RNA can be swapped to match new mutations.

Pfizer expects to have an omicronspe­cific candidate ready for the Food

and Drug Administra­tion to consider in March, with some initial batches ready to ship around the same time, chief scientific officer Dr. Mikael Dolsten told The Associated Press.

Moderna is predicting 60 to 90 days to have an omicron-specific candidate ready for testing. Other manufactur­ers that make COVID-19 vaccines using different technology, including Johnson & Johnson, also are pursuing possible updates.

Pfizer and Moderna already have successful­ly brewed experiment­al doses to match delta and another variant named beta, shots that haven’t been needed but offered valuable practice.

Not clear if tweaks are needed

So far, the original vaccines have offered at least some cross-protection against prior variants. Even if immunity against omicron isn’t as good, Dr. Anthony Fauci, the top U.S. infectious disease expert, hopes the big antibody jump triggered by booster doses will compensate.

Pfizer’s preliminar­y lab testing, released Wednesday, hint that might be the case but antibodies aren’t the only layer of defense. Vaccines also spur T cells that can prevent serious illness if someone does get infected, and Pfizer’s first tests showed, as expected, those don’t seem to be affected by omicron.

Also, memory cells that can create new and somewhat different antibodies form with each dose.

“You’re really training your immune system not just to deal better with existing variants, but it actually prepares a broader repertoire to deal with new variants,” Dolsten said.

How aggressive a mutant is also plays a role in whether to reformulat­e the vaccine. Omicron appears to spread easily but early reports from South African scientists hint that it might cause milder infections than previous variants.

How to tell if updates work

The FDA has said companies won’t need massive studies of tweaked vaccines but small ones to measure if people given the updated shot have immune responses comparable to the original, highly effective shots.

Wherry doesn’t expect data from volunteers testing experiment­al omicrontar­geted shots until at least February.

What about combinatio­n shots?

Flu vaccines protect against three or four different strains of influenza in one shot. If a vaccine tweak is needed for omicron, authoritie­s will have to decide whether to make a separate omicron booster or add it to the original vaccine – or maybe even follow the flu model and try another combinatio­n.

There’s some evidence that a COVID-19 combo shot could work. In a small Moderna study, a so-called bivalent booster containing the original vaccine and a beta-specific dose caused a bigger antibody jump than either an original Moderna booster or its experiment­al beta-specific shot.

And scientists already are working on next-generation vaccines that target parts of the virus less prone to mutate.

Omicron brings “another important wake-up call,” Wherry said – not just to vaccinate the world but create more versatile options to get that job done.

 ?? MARY ALTAFFER/AP FILE ?? Preliminar­y lab tests suggest two Pfizer doses may not prevent an omicron infection but they could protect against severe illness. And a booster shot may rev up immunity enough to do both.
MARY ALTAFFER/AP FILE Preliminar­y lab tests suggest two Pfizer doses may not prevent an omicron infection but they could protect against severe illness. And a booster shot may rev up immunity enough to do both.

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