Here are five updates on the COVID-19 vaccine over the past week:
1. Most Americans won't be vaccinated until May or June because the U.S. is getting fewer doses than expected from Johnson & Johnson, Anthony Fauci, MD, said Feb. 16.
2. Pfizer and BioNTech started a large-scale clinical trial to test the COVID-19 vaccine in pregnant women, according to a Feb. 18 announcement.
3. Pfizer's vaccine was found to be 85 percent effective after a single dose and doesn't need to be stored at ultralow temperatures, according to a Feb. 19 report.
4. Sanofi and GlaxoSmithKline began a new clinical trial for their protein-based COVID-19 vaccine candidate, according to a Feb. 22 announcement.
5. The FDA said vaccine makers won't have to conduct monthslong trials to gain authorization for COVID-19 vaccines made to combat variants of the virus, according to a Feb. 22 report.