The World Health Organization on Thursday acknowledged that coronavirus may linger in the air in crowded indoor spaces, spreading from person to person, reported AP. This came days after more than 200 scientists had urged the agency to revisit the research and revise its position.

WHO has long dismissed the possibility that the coronavirus spreads through the air except for certain risky medical procedures. However, on Tuesday, the WHO acknowledged for the first time that there was “evidence emerging” that the transmission of the coronavirus is airborne. Benedetta Allegranzi, WHO’s technical lead for infection prevention and control, had said at a media briefing in Geneva that such evidence was emerging, but it was not definitive. “The possibility of airborne transmission in public settings – especially in very specific conditions, crowded, closed, poorly ventilated settings that have been described, cannot be ruled out,” she had said. “However, the evidence needs to be gathered and interpreted, and we continue to support this.”

On Thursday, the WHO noted that studies evaluating Covid-19 outbreaks in restaurants, choir practices and fitness classes suggested the virus might have been spread in the air. It said that airborne spread “particularly in specific indoor locations, such as crowded and inadequately ventilated spaces over a prolonged period of time with infected persons cannot be ruled out”.

The WHO also recognised the importance of asymptomatic people spreading Covid-19. The UN health body has long downplayed this phenomenon. The WHO has repeatedly said such transmission was rare. “Infected people can transmit the virus both when they have symptoms and when they don’t have symptoms,” the agency said on Thursday. However, the extent of truly asymptomatic infection still remains unknown, it added.

Most countries went into a complete or partial lockdown when the coronavirus, which originated in China, began to spread earlier this year. If the WHO concretely confirms that the virus can also spread through the air, countries may have to change the public health measures they have adopted to curb the pandemic.

The global coronavirus count is now over 1.22 crore, while the toll has crossed 5.54 lakh, according to the Johns Hopkins University. More than 67 lakh people have recovered so far.

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