Federal health officials in the United States greenlighted Johnson & Johnson’s single-dose, COVID-19 vaccine this past weekend. Around the world, large trials have shown how effective the vaccines are but these studies don’t tell you everything. The World’s Elana Gordon reports on why understanding the virus’s transmissibility even postvaccine is so tricky and how scientists are taking that on.
We want to hear your feedback so we can keep improving our website, theworld.org. Please fill out this quick survey and let us know your thoughts (your answers will be anonymous). Thanks for your time!