Mask-wearing is the single most effective public health measure at tackling Covid, reducing incidence by 53%, the first global study of its kind shows.
Vaccines are safe and effective and saving lives around the world. But most do not confer 100% protection, most countries have not vaccinated everyone, and it is not yet known if jabs will prevent future transmission of emerging coronavirus variants.
Globally, Covid cases exceeded 250 million this month. The virus is still infecting 50 million people worldwide every 90 days due to the highly transmissible Delta variant, with thousands dying each day.
