U.S. regulators have authorized a fourth dose of Pfizer-BioNTech's COVID-19 vaccine for Americans 50 and older. During the recent Omicron surge, those who were boosted were 21 times less likely to die from COVID-19 compared to those who were unvaccinated, and seven times less likely to be hospitalized, CDC data shows. Separately and in addition, based on newly published data, adults who received a primary vaccine and booster dose of Johnson & Johnson's Janssen COVID-19 vaccine at least four months ago may now receive a second booster dose using an mRNA COVID-19 vaccine. COVID-19 cases in the United States have dropped sharply since a record surge in January, but have seen a small uptick over the past week, according to CDC data. A study of Israeli health-care workers suggested that the fourth dose added little additional protection in the age group.

Source: CBC News March 30, 2022 06:15 UTC