As COVID-19 vaccinations continue to be administered around the world, a coordinated global response to viral variants that may threaten the protection provided by vaccines is critical, writes a group of World Health Organization scientists, whose comments appeared in a special report published in The New England Journal of Medicine, according to a news release from University of Florida Health.
In India, a “double mutant” viral variant appears to have driven a surge of COVID-19 infection this spring with new reported cases numbering more than 300,000 a day in May.
“The variant of concern in India, known as delta, has mutations that make the virus possibly more transmissible, and antibodies due to past infections and current vaccines could be less protective against it. These characteristics, among other factors, may have contributed to the massive epidemic in India,” said Ira Longini, PhD, Professor of Biostatistics in the UF College of Public Health and Health Professions and the University of Florida College of Medicine. “As this virus spreads to other parts of the world, there may be concerns that current vaccines may be less effective, at least against infection.”
A variant overwhelming Brazil and spreading across the Americas called gamma affects immune escape, meaning people who have already had COVID-19 are more susceptible to reinfection. Current vaccines also could be somewhat less effective against gamma, said Longini, a member of UF’s Emerging Pathogens Institute and one of the article’s authors.
The authors, who are members and advisers of the expert group for the WHO Solidarity Trial, an international clinical trial testing COVID-19 treatments and vaccines, outline four priorities for a coordinated response to variants. These include global strategies to determine whether existing vaccines are losing efficacy against variants; decisions on the need for modified or new vaccines to restore efficacy against variants; efforts to reduce the likelihood that viral variants of concern will emerge; and international coordination of research and response to new variants, led by WHO.
“There is quite a bit of variation on the extent of sequencing in the surveillance systems by country,” he said. “For example, there has been extensive sequencing in the U.K., somewhat spotty sequencing in the U.S., and almost no sequencing at all in many countries.”