A side-by-side comparison of the Pfizer/BioNTech and Moderna vaccines A look at how the two authorized vaccines stack up against one another on a host of factors, including efficacy and safety. Helen Branswell STAT

In an ideal world, a pandemic vaccine could be delivered in a single shot, so supplies could be stretched to cover a lot of people. It would trigger no side effect more significant than a sore arm. And it would be easy to ship and store.

Why you still need to wear a mask after getting COVID-19 vaccine Getting the vaccine does not mean you can ignore precautions. ABC News ABC News

As the promise of a COVID-19 vaccine is fulfilled amid the rollout of the Pfizer/BioNTech and Moderna vaccines, the need to continue wearing masks, washing your hands and maintaining social distancing remains mission critical to protecting lives.

Coronavirus Is Surging: How Severe Is Your State's Outbreak? View NPR's maps and graphics to see where COVID-19 is hitting hardest in the U.S., which state outbreaks are growing and which are leveling off. NPR.org

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What the data say about border closures and COVID spread Models estimate that travel restrictions worked early in the pandemic, but became less effective throughout the year. Smriti Mallapaty nature

As countries in Europe rush to close their borders to the United Kingdom to prevent transmission of a new — and potentially more transmissible — variant of SARS-CoV-2, research has estimated the effect of international travel restrictions on COVID-19 spread earlier in the pandemic.