COVID-19 variant behind India's second wave doubles the risk of hospitalisation, says study

A new study, conducted on 377 cases of hospitalisation and 19,543 community cases from 54 lakh people in Scotland, has found that the Delta variant doubles a patient’s chances of hospitalisation. 

The variant, first identified in India amid the country’s brutal second wave, also decreases the efficacy of currently approved COVID-19 vaccines like Oxford-AstraZeneca and Pfizer-BioNTech. It is also more infectious than earlier identified COVID-19 variants.

Nevertheless, the study, published in a research letter in The Lancet, also notes that two vaccine doses still offer “strong protection” against the new, more dangerous variant.

A threat to global health infrastructure

Rising caseload of the Delta variant in the UK has forced Prime Minister Boris Johnson to rethink the UK’s much publicised reopening on June 21. Reports suggest PM Johnson is set to delay the unlock process to ensure that the Delta variant doesn’t replay the havoc it caused in India.

The protection that the Oxford-AstraZeneca vaccine offers reduces from 73 percent against the Alpha variant to 60 percent against the Delta variant. The Oxford-AstraZeneca vaccine is being administered in India under the brand name Covishield, which is manufactured by the Serum Institute of India (SII).

Similarly, the protection from the Pfizer-BioNTech vaccine, widely administered in the US, reduces from 92 percent for the Alpha variant to 79 percent for the Delta variant.

However, vaccination is still the best weapon against COVID-19 infection and two doses still offer strong protection. As per Chris Robertson, professor of public health epidemiology at the University of Strathclyde, “If you test positive, then two doses of the vaccine or one dose for 28 days roughly reduces your risk of being admitted to hospital by 70 percent.”

The authors of the article noted that while the Oxford–AstraZeneca vaccine “appeared less effective” compared to the Pfizer–BioNTech vaccine against the Delta variant, the observational nature of the study’s data makes caution necessary when interpreting vaccine protection estimates.