Here are four key updates on the COVID-19 vaccine from the last week:
1. The CDC has identified 28 cases of serious blood clots among the more than 8.7 million people in the U.S. who have received a Johnson & Johnson COVID-19 vaccine, a CDC official said May 12.
2. The FDA, on May 10, has authorized Pfizer's COVID-19 vaccine to be used in children as young as 12.
3. States won't receive any doses of Johnson & Johnson's COVID-19 vaccine next week, four sources told Politico May 11.
4. Moderna said May 6 its COVID-19 vaccine is 96 percent effective in adolescents ages 12-17, according to an initial analysis of a phase 2/3 trial.