E-Paper
Delta as infectious as chickenpox: CDC report
The document suggested universal masking, and experts said its content also pointed to the need for a booster third vaccine shot.
The Delta variant of the coronavirus spreads as easily as chickenpox and it can be passed on by vaccinated people as readily as it is spread by unvaccinated people, according to an internal document of America’s top health agency, several US news publications reported on Friday.
The document suggested universal masking, and experts said its content also pointed to the need for a booster third vaccine shot.
The Washington Post, which first reported these findings, said the document by the Centers for Disease Control and Prevention (CDC) makes the case for health officials to “acknowledge the war has changed”, citing unpublished data from outbreak investigations.
The variant was also causing more severe Covid-19 and was more likely to break through protection afforded by vaccines, but the health authority said such incidents were very rare.
“Given higher transmissibility and current vaccine coverage, universal masking is essential to reduce transmission of the Delta variant,” said the purported report, a copy of which was uploaded by the Washington Post on its website.
The variant was first detected in India, where it is implicated in the devastating second wave of infection recorded in April-May. In the months since, it has triggered new waves of infections in several countries, including some with high vaccine coverage such as the UK.
If infected, vaccinated people were found carrying the same amount of measurable viral load as those unvaccinated and it was this finding, the news reports suggested, that was behind the CDC’s course-reversal on masks recently.
The health agency changed its two-month-old guidance allowing vaccinated people to do without masks and issued a new recommendation calling for the use of face coverings in certain high-risk conditions earlier this week.
The United States is witnessing a surge in new infections, with about 70,000 every day (seven-day average) . And the CDC believes vaccinated people are also spreading the virus, although at a far lesser intensity than those unvaccinated.
The data shows there are roughly 35,000 symptomatic infections per week among 162 million vaccinated Americans, the New York Times reported on the basis of the CDC document.
The internal document recommends vaccinated people with weak immune systems must wear masks even in low-risk conditions and so should vaccinated people who come in contact with children or older adults, according to the NYT report.
But the current masking guidance is unlikely to be enough and the CDC report said, “Given higher transmissibility and current vaccine coverage, universal masking is essential.”
Experts also said the new insights about the variant underscore the need for possible change in vaccination policies, including by considering a third dose for those who are typically vulnerable to Covid-19.
“Based on the internal CDC document released (leaked) last night, it’s possible we’ll accelerate towards a third mRNA immunization - certainly for those on immunosuppressive Rx (medicines) and older groups - but also possibly universal for those eligible, that + universal masks,” wrote Peter Hotez, molecular virology specialist at Baylor College of Medicine.
