As Delta strain soars, some eye masking as a way to stop it

Unvaccinated most at risk for serious disease from contagious variant

WALPOLE, Mass. — At the Harney Academy of Irish Dance, they’re getting ready for a big national competition in Phoenix. Owner Liam Harney says the organizers of that event just eased up on one Covid restriction by allowing each dancer to bring two guests instead of one. But there’s another restriction that’s likely not going to change.

“Masks will be worn by absolutely every single person there,” Harney said. “Vaccinated or unvaccinated.”

That will be a change for some of Harney’s dancers who, in recent months, have been able to unmask if fully vaccinated, per CDC guidelines. Those under 12, not eligible for vaccination, haven’t enjoyed that privilege.

“The young kids, especially in the heat that’s happening right now, that’s extra tough with the masks trying to get through our full routines which are pretty tough, too,” said Colleen McCarthy, an Irish Dance student for 18 years.

The ‘all mask’ rule in Phoenix is likely rooted in the fact the event will combine cohorts that can’t, by law, get vaccinated with those who can -- at a time when the U.S. is seeing a rapid rise in Covid cases caused by the more contagious Delta variant.

“It is definitely creeping up in terms of the prevalence in the circulation. And that’s very alarming,” said Dr. Pei Yong Shi, PhD, who is studying vaccine effectiveness against the Delta variants at the University of Texas Medical Branch in Galveston. “This is not prediction. This is real. This is happening in front of us now.”

And it’s happening fast.

The CDC shows the incidence of Delta-caused Covid infections rising nine-fold since mid-May -- from about three percent to 26 percent.

In the West, Delta is already the dominant strain. That led Los Angeles County health officials this week to urge even vaccinated residents to begin wearing masks again when in indoor public spaces, including retail stores, workplaces and theaters.

Dr. Shi said the main problem with the Delta variant is its high transmissibility.

Given that, in Illinois, health officials are looking into whether Delta or other variants were responsible for an outbreak at a summer camp in mid-June that sickened 85, most unvaccinated. That camp did not have a policy requiring mask-use when indoors.

One fortunate stroke for the world, Shi said, is that the Delta strain dominating right now is 617.2, which is more sensitive to vaccines currently available than the other circulating Delta strain, 617.1.

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