People infected after having vaccine may also be less likely to transmit virus, initial findings show
www.theguardian.com
Researcher tracked more than 10,400 care home residents in England (with an average age of 86) between December and March, comparing the number of infections occurring in vaccinated and unvaccinated groups – using data retrieved from routine monthly PCR testing.
Both vaccines reduced the risk of infection by about 56% at 28-34 days after the first dose, and 62% at 35-48 days. The effect is maintained for at least seven weeks, the authors concluded in their analysis, which has not yet been peer-reviewed.
This data is notable, given older adults with underlying illnesses have largely been excluded from vaccine trials. It also supports the UK’s decision to extend dose intervals beyond what was studied in clinical trials.
The beneficial impact on transmission was further bolstered by the findings of a lower viral load in positive tests post-vaccination – if there is less viral material detected, that suggests a lower level of infectiousness, which is linked to transmissibility.