One year into the Covid-19 pandemic, a new variant seemingly mutates itself into existence every day. And the attention given to the worrying potential of the variants has grown in lockstep.
“Bay Area has its own scary new virus variant: Why experts are so concerned,” the San Francisco Chronicle wrote on Jan. 18. “Variant virus vs. vaccine: Why the scary new strain means we must move faster,” The Mercury News urged on the same day.
“I call them ‘scariants,’” said Dr. Paul Offit, a professor at the University of Pennsylvania and a member of the FDA’s vaccine advisory panel. “I think we scare the hell out of ourselves when we watch national television.”
Added UCSF’s Dr. Monica Gandhi, “It’s an overblown concern that the virus has somehow mutated to a variant that is so transmissible that it is overtaking the population. That is simply not occurring.”
In fact, experts say mounting evidence indicates that the threat posed by variants has been overhyped. While the current slate of variants includes some that are more transmissible or agile in evading the body’s immune response, vaccines are still able to beat them back or prevent hospitalization.
The biggest danger with a variant is that it achieves “immune escape,” a term for when an infectious agent evades the body’s immune defenses. The variants originating in South Africa and Brazil have shown the potential to reinfect those with immunity, but the defense mounted by vaccines appears to prevent severe disease and hospitalization in these cases.
“There is no ‘great escape,’ said Dr. Eric Topol, a clinical trial expert at Scripps Research in San Diego, at a Thursday talk on Covid, referring to the immune escape phenomenon. “And hopefully, we won’t see any great escape.”
The Johnson & Johnson clinical trials showed that the vaccine has an efficacy rate of 85% against severe covid, across all variants. Less data is available on the Moderna and Pfizer vaccines, which went through clinical trials before the variants started to circulate. But, anecdotally, vaccinated people aren’t ending up in the hospital with a variant.
A recent paper from the University of California, San Diego, also finds that vaccines protect against infection from variants by generating strong T-cell immunity in addition to the antibodies produced by B cells. The latter offer short-term protection against infection as the body builds up T cells, which are the long-term virus fighters.
“You’ll know a line has been crossed when people who have either been naturally infected or immunized are hospitalized when exposed to these variants,” said Offit. “That hasn’t really happened.”
Some of the variants also show potential for increased transmissibility, though those traits have not been enough to cause another surge in cases.
One of these variants, which originated in California, has grown more prevalent in samples collected at the 24th Street Bart Plaza testing site. Data from the testing site also shows that the variant was slightly more transmissible than other strains, according to Dr. Diane Havlir, co-founder of the Unidos en Salud initiative and infectious disease expert at UCSF.
But transmission across the board is at a rate much lower than at the peak of the last surge, which is good news: “We have an opportunity with three vaccines and continued diligence to public health measures to get and stay ahead of the virus locally,” she wrote.
Offit added that the variants do “create some sense of a rush” to get more people fully vaccinated. The more people who are vaccinated, the less room there is for the virus to spread and further mutate.
“It makes it all the more important to get the vaccine out there quickly to stop the spread of these viruses, and the sooner we can do that, the better off we are,” he said.
It is also reassuring that cases have continued to drop despite the variants, and the variants are so far not dramatically changing the trajectory of the pandemic, Gandhi said. For example, in Florida, where the more-contagious B.1.1.7 variant has the highest share of cases among the states, cases are falling.
Perhaps the greatest threat is the chance that a more dangerous variant could emerge in the future, though as the vaccine rollout accelerates, the virus has fewer chances to mutate.
Moreover, Gandhi said, the virus might be running out of ways to mutate. For instance, mutations that help the virus evade antibodies could also make it harder for the virus to bind to receptors that allow it to enter the body’s cells.
“Viruses cannot mutate indefinitely without mutating themselves out of existence,” she said.
And in the meantime, the experts said the same set of precautions still apply: wear a mask, maintain social distance and get vaccinated when it is your turn.