As governments around the world grapple with the spread of a more virulent variant of the coronavirus — first identified in South Africa — top health officials in the United States said Friday the new coronavirus variants present a “wake-up call” to move faster on vaccinating the population.

A highly transmissible variant, known as B.1351, has been identified in more than two dozen countries and has played a role in prompting Canada, Britain and Germany to introduce new travel bans.

Limited vaccine supplies in the European Union undergird much of the region’s restrictions on travel. The E.U.’s regulator on Friday recommended authorization of the Oxford-AstraZeneca coronavirus vaccine as E.U leaders planned to announce details of a new mechanism designed to restrict vaccine exports outside the bloc.

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Canada announced extensive border restrictions that include mandatory testing and quarantine at designated hotels for all returning travelers.

Maryland biotech company Novavax announced that its coronavirus vaccine was highly effective in preventing illness — except against the B.1351 variant.

E.U. regulators have authorized the AstraZeneca vaccine for adults despite a lack of data on its efficacy in older adults.

The European Commission has published its contract with drugmaker AstraZeneca after a heated dispute over production delays.

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Coronavirus: What you need to know

Where do things stand? See the latest covid numbers in the U.S. and across the world. In the U.S., pandemic trends have shifted and now White people are more likely to die from covid than Black people.

The state of public health: Conservative and libertarian forces have defanged much of the nation’s public health system through legislation and litigation as the world staggers into the fourth year of covid.

Grief and the pandemic: A Washington Post reporter covered the coronavirus — and then endured the death of her mother from covid-19. She offers a window into grief and resilience.

Would we shut down again? What will the United States do the next time a deadly virus comes knocking on the door?

Vaccines: The CDC recommends that everyone age 5 and older get an updated covid booster shot. New federal data shows adults who received the updated shots cut their risk of being hospitalized with covid-19 by 50 percent. Here’s guidance on when you should get the omicron booster and how vaccine efficacy could be affected by your prior infections.

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