Delta variant of coronavirus as contagious as chickenpox, says CDC

The US Centers for Disease Control and Prevention (CDC) has described the Delta variant of the coronavirus as being as transmissible as chickenpox and cautioned it could cause severe disease, the Washington Post said, citing an internal CDC document.
 
The variant was also more likely to break through protections afforded by the vaccines, but the health authority said such incidents were very rare, the CDC report posted on the Washington Post website showed. In its summary, the CDC report said Delta is highly contagious, likely more severe than other variants and breakthrough infections may be as transmissible as unvaccinated cases.

 
Still, the CDC’s figures show that the vaccines are highly effective in preventing serious illness, hospitalisation and death.
 

The findings add to evidence of how the Delta variant, the fastest and most formidable version of the coronavirus that causes Covid-19, has upended assumptions among virologists and epidemiologists about the disease. Delta has become the dominant variant globally, documented in 132 countries to date, according to the World Health Organization.
 
On Tuesday, the CDC reversed course on guidance for mask wearing, reinstituting them as a precaution against the possible transmission of the virus by fully vaccinated people.
 

The agency said it had seen evidence suggestive of this in outbreak investigations in the United States and overseas. The agency also cited high viral loads as a reason for changing guidance. On Thursday, US President Joe Biden urged local governments to pay people to get vaccinated and set new rules requiring federal workers to provide proof of vaccination or face regular testing, mask mandates and travel restrictions. The findings may stir debate about whether masks, social distancing and other measures may again be needed even in countries with broad vaccination campaigns and where lockdown restrictions have eased.
 
The CDC report said that universal mask wearing is still needed to reduce transmission in addition to vaccines.

 
“The main thing that does change is that masks will still be used and that in countries where this requirement has been lifted, it will have to be re-introduced," said Carlo Federico Perno, Head of Microbiology and Immunology Diagnostics at Rome’s Bambino Ges Hospital.