verOver a year after the US authorized its first vaccines, COVID cases continue to pile up, leaving many vaccinated people wondering: “Do I need a vaccine upgrade?” People who are fully vaccinated and boosted have been testing positive in huge numbers, particularly since the omicron-triggered wave started its relentless burn across the United States in December. Vaccines that once caused experts to declare COVID-19 a “pandemic of the unvaccinated” don’t protect as well against illness, even as they continued to protect against the most severe disease. Breakthrough infections are so common that the near-miraculous protection the vaccine promised a year ago feels very far away.
Part of the problem is that the virus that the vaccines target — the first version of the coronavirus that started spreading in early 2020 — doesn’t exist anymore. Now, regulators, researchers, and vaccine companies are turning to the next phase of the vaccine development process: finding a way to protect against the virus that’s spreading now and finding a way to protect people against future variations of the virus.
THE VIRUS THAT THE VACCINES TARGET — THE FIRST VERSION OF THE CORONAVIRUS THAT STARTED SPREADING IN EARLY 2020 — DOESN’T EXIST ANYMORE
On June 28th, an FDA committee will meet to discuss whether and how future booster doses of vaccines might specifically target emerging variants of the virus. Like the seasonal flu shot, the next vaccines may at some point protect against whatever version of the virus is going to be circulating in a particular year. At the same time, other scientists are looking into ways of making the protection from any booster shot last longer. Longer-term, COVID-19 vaccines might be very different from current shots, using different technology and protecting against viruses that don’t even exist yet. Some might not be shots but nasal sprays, which might be able to prevent even mild infections.
“Preventing severe disease was the original goal, and I understand that. At the beginning of the pandemic, that made sense,” said Akiko Iwasaki, a professor of immunobiology at Yale University School of Medicine. “But now we understand the virus better and the fact that the variants are here — I think we need to shift our thinking.”
THE NEXT VIRUS
The first step for the future of COVID-19 vaccines is to play catch-up with the recent past. After over two years, the version of the virus that was first detected in Wuhan, China, has been replaced by its more contagious and immune-evading variants. Several vaccine manufacturers have already started testing vaccines tailored to the omicron variant. An early analysis of Moderna’s omicron-specific shot showed that it generated more antibodies against the omicron virus than the original vaccine, the company announced earlier this month. The vaccine is bivalent — it’s made to protect against both the “original flavor” coronavirus and omicron.
Moderna says its booster may be “available by late summer in some markets,” wrote Elise Meyer, senior director of communications at Moderna, in an email to The Verge.
Pfizer and BioNTech are also running a clinical trial to update their shots against omicron, examining standard booster shots of the original vaccine, a version targeting only omicron, and a bivalent shot like Moderna’s. At a press briefing in April, Pfizer CEO Albert Bourla said an omicron shot might be available in the fall.
Novavax, whose vaccine might be approved soon in the US, is working on its own omicron booster. Its clinical trial testing both omicron-targeted shot and a bivalent vaccine started on May 31st. The vaccine, which has been under review by the FDA since January, seems to have less severe side effects than the other vaccines, making it potentially ideal to use as a non-disruptive booster.
But it’s still unclear if the omicron shots will work much better than the original vaccine against omicron and other variants. In one study on mice, the original vaccine “actually worked quite well, at least in the short-term,” said Larissa Thackray, an associate professor of infectious disease at the Washington University School of Medicine in St. Louis.
A VACCINE TARGETING A CURRENT OR AT LEAST RECENT VARIANT MAKES MORE SENSE THAN ONE TARGETING A MUCH DIFFERENT VIRUS
If omicron-specific vaccines don’t have a major benefit over the existing vaccines, they could be a hard sell to be authorized by the FDA. Yet despite the uncertainty, Thackray said she thinks an omicron booster is overdue. A vaccine targeting a current or at least recent variant makes more sense than one targeting a much different virus — the original strain of SARS-CoV-2, which doesn’t exist anymore.
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