Mutant’s spread raises global fears
Experts warn against dropping safeguards amid delta variant
The latest alarming coronavirus variant is exploiting low global vaccination rates and a rush to ease pandemic restrictions, adding new urgency to the drive to get more shots in arms and slow its supercharged spread.
The vaccines most used in Western countries still appear to offer strong protection against the contagious delta variant, first identified in India and now spreading in more than 90 other countries.
But the World Health Organization warned this week that easier-to-spread strains, insufficiently immunized populations and a drop in mask use and other public health measures before the virus is better contained will “delay the end of the pandemic.”
The delta variant is positioned to take full advantage of those weaknesses.
“Any suffering or death from COVID-19 is tragic. With vaccines available across the country, the suffering and loss we are now seeing is nearly entirely avoidable,” Dr. Rochelle Walensky, director of the Centers for Disease Control and Prevention, said this week in urging more Americans to roll up their sleeves ahead of the mutant’s spread.
Amid concerns about the variant, parts of Europe have reinstated travel quarantines, several Australian cities are in outbreak-sparked lockdowns — and just as Japan readies for the Olympics, some visiting athletes are infected.
The mutation is causing worry even in countries with relatively successful immunization campaigns.
In the U.S., “we’re still vulnerable for these flareups and rebounds,” said Dr. Hilary Babcock of Washington University at St. Louis.
The variants “are able to find any gaps in our protection,” she said, pointing to how hospital beds and intensive care units in Missouri’s least-vaccinated southwestern counties are filling — mostly with adults under 40 who never got the shots.
With nearly half the U.S. population immunized, Walensky said about 1,000 counties, mostly in the Midwest and Southeast, with vaccination rates below 30% “are our most vulnerable.”
But the variant poses the most danger in countries where vaccinations are sparse.
Africa is seeing cases rise faster than ever before, partially driven by the mutation, the WHO said, while areas in Bangladesh that border India are also seeing a variant-fueled surge.
The delta variant remains far from the only version of the coronavirus that’s spreading.
Scientists believe the delta variant is about 50% more transmissible than other types. Researchers are just beginning to find out why.
There are early clues that some mutations may ease a key step in how the virus slips inside human cells, said Priyamvada Acharya, a structural biologist at the Duke Human Vaccine Institute.
Still, it’s not clear if higher contagion is the reason the variant is spreading so quickly.
In Britain, its rise followed a loosening of restrictions in May, when restaurants, gyms and other businesses reopened, and thousands of fans have attended sports events.
It’s harder to tell if the delta variant makes people sicker. British experts have said there are some preliminary signs it may increase hospitalization, but there’s no evidence it is more lethal.
It fueled a devastating COVID-19 surge in India in February, and “this time around we had a lot more people who were very sick compared to before,” said Dr. Jacob John of Christian Medical College at Vellore. But he cautioned that the “explosion” of cases didn’t necessarily mean this version was more dangerous.
British researchers found two doses of either the Pfizer-BioNTech vaccine or the AstraZeneca one were only slightly less effective at blocking symptomatic illness from the delta variant than from earlier mutations — and importantly, remain hugely protective at preventing hospitalization.
But there’s a catch: Just one dose proved far less effective against the delta variant than against earlier versions of the virus. That has prompted Britain, which originally extended the gap between doses, to speed up second shots.
Experts say the Moderna vaccine, the same type as Pfizer’s, should be similarly protective. Johnson & Johnson still is studying how its one-dose vaccine fares against the variant. The company notes its shot does protect against a different mutant — the beta variant that emerged in South Africa and is considered the biggest challenge for today’s COVID-19 vaccines.
The WHO has urged governments not to lift pandemic restrictions too quickly — including saying everyone, even the vaccinated, should continue to wear masks given that the delta variant spreads more easily and no vaccine is 100% effective.
The CDC maintains it still is safe for the fully vaccinated to go mask-free. But there’s no way to know if maskless people are vaccinated and local governments can set tighter guidelines.
In Missouri, fully vaccinated Babcock makes sure she has a mask to pop on quickly if she runs into a crowd: “I feel like my new normal is holding a mask in my hand, ready to put it on if I need it.”