COVID-19 could be just a few mutations away from evading existing vaccines that protect against the deadly virus, according to the head of the Centers for Disease Control and Prevention (CDC).
“These vaccines operate really well in protecting us from severe disease and death, but the big concern is that the next variant that might emerge - just a few mutations potentially away - could potentially evade our vaccines,” CDC director Rochelle Walensky said in a Tuesday press briefing.
However, she said that grim possibility was not a current threat.
“Right now, fortunately we are not there,” she said as since current COVID-19 vaccines “operate really well in protecting us from severe disease and death.”
COVID-19 cases have been surging and across the globe - largely among those who are unvaccinated – and amid the spread of the Delta variant; the fastest, fittest and most formidable version of the coronavirus the world has encountered.
At present, virologists and epidemiologists say vaccine protection remains very strong against severe infections and hospitalizations caused by any version of the coronavirus, and those most at risk are still the unvaccinated.
But the CDC has warned that evidence that evidence is also mounting that the Delta variant is capable of infecting fully vaccinated people at a greater rate than previous versions, and concerns have been raised that they may even spread the virus.
It means even vaccinated people could pass the virus along to others similarly to how unvaccinated people do.
Viruses constantly evolve through mutation, with new variants arising. Sometimes these are more dangerous than the original.
At present, countless versions of COVID-19 are circulating, each separated by tiny changes in its genetic code.
While virologist say that many of these have no real public-health impact, the more people a virus infects, the more it has to mutate into a new, potentially more dangerous, variant.
“The biggest concern at the moment is just the sheer number of people that have the virus and therefore the sheer number of variants that are being generated,” said Andrew Read, who studies the evolution of infectious diseases at Pennsylvania State University.
“Some of those might be the jackpot which are even fitter than Delta.”
World Health Organization officials has called Delta the “most fittest” variant yet, since it spreads more easily and may lead to more severe cases and an increased risk of hospitalization than other variants like Alpha, the variant discovered in the UK.
New research also indicates that a single vaccine dose doesn’t hold up as well against Delta as it does against other coronavirus strains.
Recent Public Health England studies found that two doses of Pfizer’s vaccine were 88 percent effective at preventing symptomatic COVID-19 from Delta, while a single shot was just 33 percent effective.
That is compared to 95 percent efficacy against the original strain, with 52 percent after one shot.
Until there is more data on Delta variant transmission, disease experts say that masks, social distancing and other measures set aside in countries with broad vaccination campaigns may again be needed.
Even though Delta is already the most transmissible variant, health officials have warned it still acquire combinations of mutations that make it even better at spreading, while it is also possible that two separate variants could combine their mutations to produce an even more infectious strain.