When the mRNA vaccines rolled out at the end of 2020, we were told it would be quick and simple to tweak the shots should new variants of concern appear. But when variants did appear, we stuck with the original vaccines.
Scientists developed and tested variant-specific shots, but soon learned that an updated shot tailored to these variants wouldn’t be necessary — at least, not yet. It would take a significant number of mutations for a variant to totally evade the current vaccines. Rather than creating, testing, manufacturing and distributing tweaked shots, vaccine scientists will likely work on improving the very powerful ones we already have.
Even with omicron — a variant that may potentially chip away at the effectiveness of our shots to a degree — the original vaccines’ effectiveness won’t drop to zero. Some vaccine manufacturer executives say there will be a marked difference with omicron, but epidemiologists predict protection against severe disease and death will likely stay strong.
And although protection against symptomatic infection wanes over time and may even diminish with variants, evidence shows that a booster shot quickly restores the very high level of protection people had after their original doses.
“People should just feel really confident that we have really great vaccines,” said Catherine Blish, a professor of medicine in infectious diseases at Stanford University School of Medicine.
Why don’t we have variant-specific boosters?
The main reason we don’t have variant-specific shots is that we just haven’t needed them yet, according to Blish. The original vaccines still work great against the variants that have been circulating.
“It’s a misconception that the vaccines we have don’t target delta — in fact, they’re perfectly good at targeting delta,” Blish said. Delta spreads extremely easily, but it’s not an escape variant. It’s essentially the original virus with a few mutations.
Our vaccines saw a four-fold reduction in antibodies against delta and a 10-fold reduction in antibodies against beta, according to Blish. Scientists actually had developed and tested a delta-specific vaccine but realized it wouldn’t be necessary due to the power of the original shots.
They also looked into a beta-specific shot. And although they found that that shot was indeed better at neutralizing the beta variant, beta never took off in a meaningful way. Ultimately, it didn’t make sense to invest a ton of resources in creating and distributing a new vaccine when the ones we have already work so well.
“The reality is that our vaccines are much, much better than we need them to be — so even that 10-fold reduction is OK,” Blish said.
Even if the shots take a hit against a mutation-heavy variant like omicron, that doesn’t mean their effectiveness will shatter entirely. When scientists say the shots may “take a hit” against a variant, they’re mostly talking about infections — not severe illness and death (which is the main point of the vaccines).
After vaccination, our immune system has the ability to remember the SARS-CoV-2 virus, mutations and all. This can help us produce new antibodies that target new variants and assist in keeping us out of the hospital, Chise ― a senior scientist in vaccine research and development who worked on the Moderna COVID vaccine ― told HuffPost. (Chise asked to keep her name private because of her job.)
The vaccines are polyclonal, which means they’re able to attack the virus from multiple angles and are well-equipped to handle mutations. And although protection from the vaccines against symptomatic infection wanes over time, a third dose of the original shot quickly boosts neutralizing antibody levels and greatly strengthening protection against symptomatic infection, even from variants like delta.
Chise, who has gained popularity on Twitter by sharing vaccine research and insights, said a booster dose of the original vaccine has been shown to be beneficial, just as any variant-specific shot might have been. Furthermore, two doses continue to provide great protection against severe disease.
“People should just feel really confident that we have really great vaccines.”
Will we need new COVID vaccines?
The good news is that it’s easy to quickly create a new mRNA vaccine — but you still have to conduct the safety and efficacy testing, which would take a few months at a minimum.
“We’re in a good position to respond and really, the question is: Is a new variant going to arise that has that capacity to really escape from our vaccine-mediated immunity?” Blish said.
Both Pfizer and Moderna are already researching whether a new version of their shots is needed in light of omicron, and both companies have said one could be available next year if scientists determine it’s necessary.
Overall, it’s too soon to tell what’s going to happen. Omicron has several mutations, but that doesn’t necessarily mean we’ll need tailored vaccines. Existing vaccines should still help — especially with a booster, and especially when it comes to preventing severe outcomes — but we should have concrete data on that in a month or two.
Furthermore, scientists may decide that a vaccine specifically targeting a new variant might not make sense. All of the variants out there right now evolved from the original strain — which matters when it comes to the type of shot we’re using. If, for example, we had started using a beta-specific vaccine when delta took over earlier this year, we may have ended up in an even messier spot. The original vaccine, being polyclonal, has broader coverage than a variant-specific shot would, and has likely saved a lot of people.
“I think you could potentially run into an issue if you got a little bit too specific,” Chise said.
The reality is that we’ll be living with COVID for a long time. Some experts believe we’ll move from a pandemic to an endemic, meaning we may have to get a COVID vaccine every year or so. What that specific shot may look like two, five or 10 years down the line is unknown right now.
Chise guesses that scientists probably won’t be releasing tweaked shots targeting new variants anytime soon, but will most likely focus on improving the vaccines we already have (think: adjusting the dosage, lowering the number of doses needed, or exploring different delivery methods like the nose).
“The original vaccines are so broad that you would be better off improving those than trying to do something of the like because you don’t really know what variants are going to be circulating,” Chise said.
Experts are still learning about COVID-19. The information in this story is what was known or available as of publication, but guidance can change as scientists discover more about the virus. Please check the Centers for Disease Control and Prevention for the most updated recommendations.