Factbox: Latest on the worldwide spread of the coronavirus European Union leaders will meet on Thursday to try to speed up the production and rollout of vaccines in a race against the emergence of new variants that some fear could bring a third wave of the pandemic across the continent. Reuters Staff U.S.

* The World Health Organization is working with the European Commission to coordinate vaccine donations for other countries on the continent, the head of its European office said.

Shorter, more frequent lockdowns could lead to fewer COVID-19 cases, study finds A new study out of Toronto suggests that shorter, but more frequent lockdowns could lead to fewer cases of COVID-19. Coronavirus

TORONTO -- A new study out of Toronto suggests that shorter, but more frequent lockdowns, could lead to fewer cases of COVID-19.

Pfizer to study booster shot aimed at virus variant Pfizer and its partner BioNTech said Thursday they are beginning a stu Peter Sullivan TheHill

Pfizer and its partner BioNTech said Thursday they are beginning a study to test whether a third shot of their COVID-19 vaccine will help protect against variants of the virus.

The virus can sicken children in very different ways, a new study finds.

A large nationwide study has found important differences between the two major ways children have become seriously ill from the coronavirus. The findings may help doctors and parents better recognize the disease and understand more about the children who are at risk for either condition.

Why COVID vaccines are so difficult to compare Despite the widespread roll-out of several vaccines, it could be months before they can be ranked. Heidi Ledford nature

Yusuff Adebayo Adebisi knows that a vaccine that offers 70% protection against COVID-19 could be a valuable tool against the coronavirus pandemic in Nigeria — especially if that vaccine is cheap and doesn’t have to be stored at extremely cold temperatures. But what if another vaccine — one that is more expensive to buy and to store — was 95% effective?