There is a much higher risk of brain blood clots from Covid-19 infection than there is from vaccines against the disease, British researchers said on April 15, after the rollout of inoculations was disrupted by reports of rare clots.

Europe’s medicines regulator said on March 31 the EMA had not identified any risk factors such as age, sex or a previous history of blood clotting disorders, for clotting cases reported after inoculation with AstraZeneca’s Covid-19 vaccine.

EU leaders voiced frustration on March 25 over a massive shortfall in contracted deliveries of AstraZeneca Covid-19 vaccines, as a third wave of infections surged across Europe.

The U.S. Centers for Disease Control and Prevention (CDC) said on March 8 that individuals inoculated against Covid-19 can meet in small groups with other vaccinated people without masks, but that they should keep wearing them outside the home.

Covid-19 vaccine makers told Congress on Feb. 23 that U.S. supplies should surge in the coming weeks due to manufacturing expansions and new vaccine authorizations.

The head of the U.S. Centers for Disease Control and Prevention said on Feb. 14 it is “absolutely” too soon to lift mask mandates, citing daily Covid-19 case numbers that despite recent declines remain more than double the levels seen the summer of 2020.

President Joe Biden said it will be difficult for the United States to reach herd immunity, at least 75% of the population inoculated against the coronavirus, by the end of the 2021 summer.

President-elect Joe Biden’s plan to boost the Covid-19 vaccine rollout – including by spending $20 billion to create mass vaccination centers – should help speed up putting shots into the arms of millions of Americans, experts and officials told Reuters.

Nearly 9 million Americans had been given their first Covid-19 vaccination dose as of Jan. 11, the U.S. Centers for Disease Control and Prevention said, as states scrambled to step up inoculations that have yet to slow the roaring pandemic.

China approved a Covid-19 vaccine developed by an affiliate of state-backed pharmaceutical giant Sinopharm on Dec. 31, the country’s first approved shot for general public use as it braces for increased transmission risks over winter.