What is the WHO’s mask guidance towards the Covid-19 Delta variant?

In late May, the CDC released guidance that masks do not need to be worn outdoors so long as physical distancing is possible. More recently, as the World Health Organization (WHO) releases new information on the delta variant, the CDC may have to rethink its decision, especially as it relates to areas where vaccination rates are low.

 Delta variant and new mask mandates

On 25 June, WHO Director-General Dr. Tedros Adhanom assured the international community that his organization is closely following and researching the delta variant. In his comments,  he stated that “Delta is the most transmissible of the variants identified so far,” has been found in at least 85 countries, and “spreading rapidly among unvaccinated populations.”

To slow the spread of the delta variant and to make it harder for new strains of the virus to emerge, Dr. Tedros stated that it is now “more urgent that we use all the tools at our disposal to prevent transmission.”

During the same media press conference, the WHO Assistant Director-General, Dr. Mariangela Simao, warned even those who have received a covid-19 vaccine could still be susceptible to infection by the delta variant. For individuals to help slow the spread, even those who are a part of the two percent globally that have received their shots “need to continue to use masks consistently, be in ventilated spaces, hand hygiene, respiratory etiquette, the physical distance, avoid crowding.”

What have scientists confirmed about the delta variant?

New science on covid-19 and the variants are coming out every day. The WHO reviews these reports and studies carefully and provides guidance once the information has been vetted.

The organization has stated that the delta variant is more transmissible than the alpha variant, which emerged in the United Kingdom. However, there is no evidence that those infected with delta are contagious for a longer period of time. This variable, the time a person would transmit the virus, poses a serious threat to our understanding of the virus as quarantine and social isolation timelines would need to be adjusted to stop the spread. At this point, with the delta variant, it does not look like that guidance will need to be modified.

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The CDC has stated that they assume that the delta variant is more contagious but has not identified a figure to associate with the hypothesis. The organization has also reviewed the evidence indicating that delta may be more resistant to some therapeutics, including monoclonal antibody treatments. As far as vaccines are concerned, the CDC has stated that the vaccines available may be slightly less effective in preventing infection.

What states are susceptible to the growing spread of the delta variant?


Both the CDC and the WHO have warned that areas with unvaccinated people face a greater risk to the delta variant. In the US, around 53% of the population is at least partially vaccinated. The rate is higher for adults, where the average stands at around 66%. Only children between the ages of twelve and seventeen can receive a vaccine, leaving a sizable amount of the population ineligible.


More concerning is that when looking at the entire population, twenty-four states have vaccinated less than half of their population, meaning that the delta variant could begin to increase community transmission in these areas at an alarming rate.

However, fifteen states have already met the President’s goal of having at least seventy percent of adults partially vaccinated by the Fourth of July. Although, in four states -- Mississippi, Louisiana, Wyoming, and Alabama -- this number is less than half.