Center for Disease Control and Prevention (USCDC) — the top American public health agency has reversed its guidelines for indoor mask usage by persons who are vaccinated against COVID19.

“To maximize protection from the Delta variant and prevent possibly spreading it to others, wear a mask indoors in public if you are in an area of substantial or high transmission,” states CDC in its guideline for people who have received both the doses of COVID19 vaccines.

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The latest guidelines, that were issued yesterday, on July 27, also state that people might choose to wear a mask regardless of the level of transmission if they have a weakened immune system or if, because of age or an underlying medical condition, or are at increased risk for severe disease, or if a member of household has a weakened immune system, is at increased risk for severe disease, or is unvaccinated.

“If you’ve been around someone who has COVID-19, you should get tested 3-5 days after your exposure, even if you don’t have symptoms. You should also wear a mask indoors in public for 14 days following exposure or until your test result is negative. You should isolate for 10 days if your test result is positive,” the CDC added in its advice for those who are fully vaccinated.

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Delta variant a major worry

While informing the press about the measured needed to contain the COVID19 outbreak by the Delta variant, CDC chief Rochelle Walensky cited new data that reflects that even though vaccines remain highly effective, rare breakthrough cases with the Delta variant have a greater risk of transmission.

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Walensky was quoted as saying that new studies show that fully vaccinated people, who do become infected, carry as much virus as unvaccinated people which suggests that they may be able to transmit the infection to others.

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Two months back, in May, the CDC had relaxed the requirement of indoor masks by those who had received both the doses of COVID19 vaccine.

CDC’s u-turn is in accordance with the World Health Organization (WHO) that has repeatedly emphasised on the need to wear masks, even by those who are vaccinated, in order to impede the spread of the Delta variant.