COVID-19 vaccination tied to reduced household transmissionCOVID-19 transmission among household members may be reduced 40% to 50% when a person has been vaccinated 21 days or more, according to a New England Journal of Medicine letter to the editor yesterday.The researchers looked at more than 1 million household contacts in England from Jan 4 to Feb 28 and found that both percentages and absolute numbers showed fewer secondary cases when the index patient had received at least one dose of the AstraZeneca/Oxford or the Pfizer/BioNTech COVID-19 vaccine 21 or more days prior.
Of the index patients that were vaccinated, the researchers add that 93% hadn't received their second vaccine dose yet.By cross-referencing all lab-confirmed COVID-19