New data shows that the Covid-19 vaccines currently on the market may not be as effective at protecting against new, more contagious strains of the coronavirus, said White House Health Advisor Dr. Anthony Fauci, on Thursday.
A handful of new strains of the coronavirus have emerged overseas, giving scientists cause for concern. Some variants identified in the UK, South Africa, and Brazil appear to be more transmissible than previous strains, but not necessarily more deadly.
While it’s no surprise that the virus is mutating, researchers are quick to figure out what the changes could mean for recently developed life-saving vaccines and therapeutics for the disease.
Some early results, published on the bioRxiv preprint server and not yet peer-reviewed, indicate that variant 501Y.V2 identified in South Africa may evade the antibodies of some coronavirus treatments and reduce the effectiveness of the current line of vaccines available.
“In addition, 501Y.V2 shows significant or complete leakage of neutralizing antibodies in COVID-19 convalescent plasma,” wrote researchers at the South African National Institute for Communicable Diseases. Their conclusions, they said, “highlight the prospect of re-infection … and may anticipate decreased effectiveness of current spike-based vaccines.”
Even if the drugs are less effective, they will likely still offer enough protection to make the vaccines worthwhile, Fauci said during a White House press conference.
Both Pfizer and Moderna vaccines have been shown to be highly effective, creating a “cushioning effect” that would allow some decrease in their effectiveness.
“We’re following the one in South Africa very closely, which is a bit more worrying, but nothing we don’t think we can handle,” said Fauci.
A decline in the effectiveness of vaccines would be “all the more a reason why we should vaccinate as many people as possible”. Mutations occur when the virus spreads and replicates, which can be suppressed if enough people are vaccinated against the disease to build what is known as herd immunity, he explained.
“Bottom line: We’re very careful. There are alternative plans if we ever need to modify the vaccine. It’s not a very burdensome thing, we can do it given the platforms we have,” said Fauci.
Dr. Rochelle Walensky, the new director of the Centers for Disease Control and Prevention, said Tuesday that while the vaccines will work against the mutated variants, they may not be as effective as clinical trials.
“I’m very optimistic about what these variants will look like,” Walensky said in an interview with the JAMA Network. “I could be wrong. We might find variants and variants pop up … where the vaccine is less effective, but I’m still optimistic right now.”
To date, the United States has not detected any cases of Covid-19 with the strain identified in South Africa, Fauci said, although he added that the level of surveillance for the strains is “not what we would have liked”.
Another study, printed in bioRxiv by Pfizer and the scientists at BioNTech, found that their Covid-19 vaccine is likely to be just as effective against the mutant, infectious strain discovered in the UK. The US has so far identified at least 144 cases with this variant. according to current data from the CDC.
The study’s authors warned that the rapid spread of Covid variants around the world required “continuous monitoring of the importance of changes to sustained protection from currently approved vaccines”.
– CNBC’s Reuters and Sam Meredith contributed to this report.