Moderna and Pfizer-BioNTech shots could be given to the youngest kids as early as June 21.

US adults are now only eligible for the vaccine under certain circumstances.

Health Canada has given the single COVID-19 shot the official greenlight for use in people 18 and older.

Health authorities in both countries announced that people under certain age cutoffs are now ineligible for the Spikevax COVID-19 shot due to its association with heart inflammation.

Both of the mRNA vaccines available in the US are highly effective against severe COVID-19, but recent studies suggest that Moderna’s elicits a stronger immune response and might be better at preventing breakthrough infections.  

The organization implored nations to wait on booster shots until the global vaccination rate increases, but several of the world’s more well-off countries have expressed their intentions to offer them regardless.

Scientists at the US CDC report no red flags in a preliminary analysis of the safety of Pfizer/BioNTech’s and Moderna’s mRNA-based immunizations among expectant mothers.

The chance of developing cerebral venous sinus thrombosis was nearly 10 times higher in the two weeks following a diagnosis of SARS-CoV-2 infection than after receiving an mRNA vaccine, a data analysis finds.

Mix-and-match shots could simplify vaccine rollout and stimulate more-robust immune responses. Ongoing clinical trials will soon give answers.

Johnson & Johnson’s one-shot immunization could reach people’s arms as early as March 2.

Johnson & Johnson’s vaccine is less effective at preventing COVID-19 than other approved vaccines are, but experts say it could still be an important tool in curbing the pandemic.

New data suggest that the company’s approved COVID-19 vaccine protects against different virus variants, but could be less effective against the one that originated in South Africa.

The head of Operation Warp Speed says that by spreading out doses of the Moderna vaccine, more people would be able to get some level of protection sooner, a strategy opposed by other experts.

The results mark the second experimental COVID-19 vaccine to show high efficacy, but the study is not complete and the data have not been peer reviewed.