Effect of Covid-19 Vaccination on Transmission of Alpha and Delta Variants.
David W EyreDonald TaylorMark PurverDavid ChapmanTom FowlerKoen B PouwelsA Sarah WalkerTim E A PetoPublished in: The New England journal of medicine (2022)
Vaccination was associated with a smaller reduction in transmission of the delta variant than of the alpha variant, and the effects of vaccination decreased over time. PCR Ct values at diagnosis of the index patient only partially explained decreased transmission. (Funded by the U.K. Government Department of Health and Social Care and others.).