The vaccines are working
In the United States, their field efficacy is better than in clinical studies and trials
Covid-19 vaccines work magnificently. In the face of a lot of noise about breakthrough infections, and against the backdrop of an irrational fear of so-called variants of concern (we should fear them, but rationally), this merits repetition — vaccines are working better than they were expected to. According to a July 30 Kaiser Family Foundation analysis of breakthrough infections in 24 states in the United States (US), only between 0.01% and 0.90% of those fully vaccinated were infected by the SARS-COV-2 virus. Data on hospitalisations and deaths, from 19 of 24 states, gets even better. Among the vaccinated, a range of 0.00% (eight of the states) to 0.06% were hospitalised; and a range of 0.00% (in 17 of the states) to 0.01% died. The tabulation of deaths includes those from all causes. These numbers are far better than the efficacy of the vaccines used in the US. They are also better than what the study of the efficacy of one of the vaccines in preventing serious infections and hospitalisations in the case of the Delta variant suggested. In sum, the field efficacy of the vaccines has actually turned out to be better than that measured in clinical studies and trials — even against the variants.
There is no comparable information available for the United Kingdom (UK) — almost all data on breakthrough infections is anecdotal or based on clinical studies — just as there is none available for India. Among the four vaccines approved for use in the UK is Astrazeneca/oxford. Most Indians, so far, have received its locally-made version, Covishield. According to the latest clinical studies, two doses of this vaccine are 67% effective against the Delta variant and 74.5% effective against the Alpha strain of the virus. It is likely that the field data ends up showing a better efficacy, just as it does in the case of the MRNA vaccines that account for much of the vaccinations in the US.
The catch is that all this data, both on efficacy and breakthrough infections, are for fully vaccinated people. One dose of Covishield, for instance, is only 30% effective in preventing serious infections. Till Saturday night, India had fully vaccinated only 10.8% of its adult population. But August is expected to see a sharp increase in this number as many in the 18-45 years age group — this cohort started receiving vaccines on May 1 — become eligible for their second shots. The sooner India improves that proportion, the better its chances of mitigating or avoiding a third wave.