Johnson & Johnson's also-ran COVID-19 vaccine has been cleared in the EU as a booster shot, although its role in the US could be impacted by new data on rare blood clots.
Three hurdles to allowing booster COVID-19 vaccinations for all adults in the US fell in swift succession on Friday, clearing the way for wider use of the Pfizer/BioNTech and Moderna shots.
The US is now pressing ahead with plans to extend its COVID-19 vaccination campaign to younger children aged five and over, prompting a debate about the policy in other countries.<
A US study has found that the immunity afforded by COVID-19 vaccines is much stronger than that stimulated by infection with SARS-CoV-2 in unvaccinated individuals.
The US looks set to see a big expansion of the country's COVID-19 vaccination drive, with shots looking likely for children aged five to 11 as well as a fourth dose for adults who are immun