Covishield only 33-60% effective against Delta variant of SARS-CoV-2, warns top US health expert

American epidemiologist Eric Feigl-Ding, who is a senior fellow at the Federation of American Scientists, has warned that the Oxford-AstraZeneca COVID-19 vaccine is only 60 percent effective against the Delta variant.

The Delta variant, which has been dubbed a variant of concern by the World Health Organization (WHO), was first detected in India and is believed to have catalysed the explosive second wave of the pandemic in the country.

The triple mutant variant referred to as the B.1.617.2 strain by scientists and doctors has the potential to elude the AstraZeneca vaccine (Covishield). Eric Feigl-Ding has warned that one shot of the Oxford jab has limited effectiveness (at around 30 percent) against the Delta strain of SARS-CoV-2. This news is of particular concern to India as Covishield is the most extensively administered vaccine in the country.

Citing a study, Eric Feigl-Ding tweeted: “The efficacy of AZ [AstraZeneca vaccine] against Delta variant is not 90 percent (it is 60 percent), Pfizer is 88 percent in one non-trial study. However, one dose of the vaccine (both types averaged) is just 33 percent. And many countries are just one dose vaccinated.”
Notably, in several countries, the Oxford-AstraZeneca shot and the Pfizer COVID-19 vaccine candidate are the backbone of their inoculation programme. This, according to Feigl-Ding, explains why despite high vaccination coverage in the United Kingdom, the United States, and many European countries, the Delta variant of the novel coronavirus is spreading at an alarming rate.

The noted American health expert cautioned: “Please take Delta variant seriously — it’s the fastest transmission variant known to date. Much, much faster. And it has somewhat vaccine evasion, especially 1 dose, and it is much more severe (higher risk of hospitalisation).”