The US Centers of Disease Control and Prevention on Tuesday said that vaccinated people need to wear masks as COVID-19 cases are surging in the country due to Delta variant. Explaining the change in CDC’s stance, US chief virologist Anthony Fauci told CNN that “The science didn’t change, the virus did.”

He said the change in CDC guidance is a sign of the change the Delta variant has carved into the pandemic landscape.

Before Tuesday, only unvaccinated people were asked to wear masks indoors. But with the spread of the Delta variant, which was first found in India and battered its healthcare system, the CDC issued revised guidelines. According to the CDC, only 49.2% of the US population is fully vaccinated against COVID-19.

Also read: List of countries safeguarding themselves from COVID’s Delta variant

According to some experts, the rule was changed to make sure that unvaccinated Americans wear masks. But the CDC said the decision was made after new data revealed that Delta variant was infecting vaccinated people, making it more likely they could spread the virus.

With nearly all 50 states reporting a surge of new cases averaging at least 10% more than the week before, US Surgeon General Dr Vivek Murthy said the US is seeing just how dangerous the variant is in real time.

Also read: The difference between the Delta and Delta Plus variants of COVID-19

He added that wearing masks will help reduce the spread, getting jabbed is still important to end the pandemic.

The vaccination programme in the US has slowed down and the White House has roped in celebrities to create awareness among youngsters to get COVID vaccine.

Many cities in the US, including New York, Los Angeles and California, have asked health workers and public workers to get tested every week or show proof of vaccination.

In US, more than 4.13 million kids have been infected with COVID-19 since the outbreak of the pandemic. The US is still the worst-affected country by the deadly virus with more than 34.5 million cases and 611,007 deaths.