Does the Indian variant of Sars-CoV-2, B1.617.2, have the capacity to escape vaccines? Is it really more transmissible than the Kent variant, and by how much? Those are the urgent questions which government scientific advisers are going to have to try to answer over the next week or two – and the answers will have profound consequences for life in Britain over the next few months. If the reopening of society and the economy is to be stalled, or even reversed – as some doctors, including the BMA seem to want – it will suppress an economic recovery, and depress an extremely large number of people who had been led to believe that the reopening was ‘irreversible’, to use the Prime Minister’s word.
We don’t have much data to answer the above questions at present, but one piece of evidence which will be taken into account is an observational study of 3,235 healthcare workers based at the Indraprastha Apollo Hospital in Delhi. The group, all of whom had been vaccinated with the Covishield vaccine – as the AstraZeneca vaccine is branded in India – were subsequently tested for Covid 19. Of the 3,235, 85 were found to have the infection, 65 of whom had been fully-vaccinated and 20 of whom had had one jab. The study, reported in the Hindustan Times, observed that the hospitalisation rate was just 0.06 per cent – which means that just two of the workers can have suffered a serious enough illness as to require hospital treatment. There were no ICU admissions or deaths in the group.
The study is of limited value in calculating the efficacy of the AstraZeneca vaccine against the B1.617.2 strain. It is an observational study, with no control group of unvaccinated people to compare against the vaccinated group.