Vaccine response may be weaker in elderly; Merck drug shows promise in reducing virus level
New data provide a clue as to why some COVID-19 survivors may need only one dose of the two-dose Pfizer/BioNTech and Moderna Inc vaccines
New data provide a clue as to why some COVID-19 survivors may need only one dose of the two-dose Pfizer/BioNTech and Moderna Inc vaccines