(Reuters)

The United States Centers for Disease Control and Prevention has not revised its masking guidance, even as the infectious Delta variant of COVID-19 continues to sweep the United States, driving up case counts, CDC director Rochelle Walensky said during a Thursday (July 22) press call.

Walensky declined to say if the CDC is considering changing the guidance.

The CDC in May relaxed its guidance so that fully vaccinated people did not need to wear masks in most public spaces.

Her comments come a day after U.S President Joe Biden said that the CDC is likely to advise unvaccinated children to wear masks in school as districts around the country prepare to reopen for the coming school year.

The seven-day average of new cases in the United States is up 53 per cent over the previous week, Walensky said.

The Delta variant, which was first found in India, now comprises more than 80 per cent of new cases nationwide and has been detected in more than 90 countries.

Some hospitals around the United States are reaching their capacity limits as cases of COVID-19 continue to surge, Walensky said on the call.

The uptick in cases is concentrated in regions of the United States with lower vaccination rates. Florida, Texas and Missouri account for 40 per cent of all new cases nationwide, with around 1 in 5 of all new U.S. cases occurring in Florida, White House COVID-19 task for director Jeffrey Zients said.

Zients said that the United States will continue to distribute tens of millions of COVID-19 vaccines around the world.

The White House in June announced plans to distribute around 80 million COVID-19 vaccines globally.

Top U.S. infectious disease expert Anthony Fauci said there is no reason for people who received Johnson & Johnson’s COVID-19 vaccine to assume that they need to get an additional shot of Pfizer Inc’s or Moderna Inc’s vaccines to protect themselves against new variants.

The CDC and U.S. Food and Drug Administration are reviewing data to see if there is waning immunity in vaccinated people to determine if additional booster shots are needed.