Pfizer is testing a third Covid vaccine dose in young kids, delaying trial resultsPfizer and BioNTech are testing a third dose of a Covid vaccine for young children. The third dose is a lower amount than the adult doses.Pfizer is testing a third Covid vaccine dose in young kids, delaying trial results
How does the Delta variant dodge the immune system? Scientists find clues.One dose of vaccine is not enough to protect against the Delta and Beta variants, new research suggests, and even people who have had Covid-19 should be immunized.How does the Delta variant dodge the immune system? Scientists find clues.