At a press briefing in Geneva on Friday, WHO officials said masks should stay on, even for those who have received both doses of a vaccine series.
“Vaccine alone won’t stop community transmission,” said Mariangela Simao, the WHO’s assistant director-general for access to medicines and health products. “People need to continue to use masks consistently, be in ventilated spaces, hygiene, physical distance, avoid crowding.”
Simao said public health measures continue to be “extremely important” as countries cope with outbreaks of the COVID-19 Delta variant, despite high vaccination rates.
“People cannot feel safe just because they’ve had the two doses. They still need to protect themselves,” Simao said.
While COVID-19 vaccines have shown to be effective in preventing severe disease and death, including against the Delta variant, WHO officials say it is a “dangerous variant” and fully vaccinated people can be part of its transmission chain if measures aren’t maintained.
The news comes as countries continue to ease public health measures and offer new guidelines for those who are fully vaccinated.
The U.S. Centers for Disease Control and Prevention announced on May 13 that fully vaccinated Americans do not need to wear masks outdoors and can avoid wearing them indoors in most places.
Canadian guidance, released on Thursday, suggests that those who are fully vaccinated against COVID-19 can hug each other, attend barbecues and have a small group of friends over for dinner without wearing a mask or staying apart.
However, the Public Health Agency of Canada says Canadians might still want to protect themselves in certain situations such as at crowded concerts, sports events or house parties.
The Delta variant, first identified in India, has now become the dominant strain in the U.K. and accounts for about one in every five new coronavirus infections in the U.S.
Canada’s chief public health officer Dr. Theresa Tam warned on Friday that the Delta variant continues to pose a real risk in Canada based on international experience.
Between April 25 and May 23, Canada saw a four-fold increase in the proportion of Delta cases, with the majority of them being found in unvaccinated or partially-vaccinated people, according to the latest modelling data.
The modelling shows that if the Delta variant becomes the predominant strain, Canada could once again risk exceeding hospitalization capacity as the variant is 50 per cent more transmissible than the original strain of COVID-19, and results in more severe infections.
However, if Canada hits around 80 per cent of the population fully vaccinated, the modelling suggests that a fourth wave could be avoided.
Until that mass vaccination level is reached, Tam suggested that personal protective measures like mask-wearing will remain important.