Covid-19: Científico principal de Pfizer analiza eficacia de vacuna y variantes

Pfizer announced it will supply 200 million doses of its COVID-19 vaccine for the U.S. by the end of May and is aiming to ship 2 billion doses globally this year. The vaccine is over 90% effective according to clinical trials conducted in 2020, but more testing needs to be done to see how well it protects against the new variants.

Fuente: Youtube