A new study has suggested that a single dose of the Oxford AstraZeneca COVID-19 vaccine could provide a high level of protection, not just against infection but also against transmission of the virus.
University of Oxford researchers swabbed study participants in the U.K. every week and found a 67% reduction in positive swabs among participants who had been vaccinated.
Their analysis, released as a preprint Tuesday, also supports spacing out doses and estimates good efficacy after just one shot of the Oxford-AstraZeneca vaccine.
The two COVID-19 vaccines that are currently authorized in the U.S. are both mRNA vaccines, both of which are administered as two shots given a few weeks apart. The United States invested $1.5 billion to secure more 300 million doses of the AstraZeneca vaccine last spring