© Imperial College London/KJN
The press release led with the claim that "double vaccinated people were three times less likely than unvaccinated people to test positive for the coronavirus" (0.4% vs 1.2%). This is clearly misleading as an indication of vaccine effectiveness, however, as younger people were both less likely to be vaccinated and more likely to test positive. As the report itself admits:
"These estimates conflate the effect of vaccination with other correlated variables such as age, which is strongly associated with the likelihood of having been vaccinated and also acts as a proxy for differences in behaviour across the age groups."Presumably, the headline was chosen by a politically savvy communications officer who did not want to draw attention to the fact that the study found a lower vaccine effectiveness than other studies such as those of Public Health England.
Comment: If vaccines were effective and the 'answer' to Covid, they would not need marketing schemes to manipulate public perceptions to increase acceptance.