In the light of new evidence from Public Health England (PHE) that a single dose of AstraZeneca vaccine offers notably lower protection against the virus variant B.1.617.2, Kerala should think about vaccinating its vulnerable population above 60 years with two doses of the vaccine as soon as possible to bring down mortality due to COVID-19, some public health experts feel.
This is especially important as B.1.617.2 variant has emerged as the dominant virus strain in Kerala and has been responsible for the huge increase in cases and mortality during the second wave of COVID-19.
Last Thursday, PHE announced its data on vaccine efficacy to the U.K. government. As per it, one dose of AstraZeneca vaccine provided only 31% protection and two doses raised this to 81% protection against symptomatic disease caused by B.1.617.2.
In the context of the increasing circulation of the variant, it recommended the uptake of two doses amongst the vulnerable population. Concerned that B.1.617.2 is 50% more transmissible than B.1.1.7, the U.K. government has now accelerated the vaccination of those above 50 years by shortening the dosage interval of AstraZeneca vaccine from 12 weeks to eight weeks.
Ironically, U.K.’s decision to shorten the dosage interval has come at a time when the Indian government has decided to extend the interval between first and second doses of Covishield from 12 to 16 weeks, citing evidence from the U.K.
The expert committee on COVID-19 in the State had last week recommended to the government to cover as many people as possible with at least one dose of vaccine. This was on the basis of evidence that the maximum benefit of vaccination is derived from the first dose and that with adequate coverage, it can bring down disease transmission and serious disease.
“This recommendation would have been ideal if we were dealing with the original strain of SARS-CoV-2 or the B.1.1.7 variant. In Kerala, the B.1.617.2 is emerging as the dominant strain. New evidence suggests that two doses of Covishield are necessary to give protection against symptomatic COVID-19 caused by B.1.617.2. The government should administer the second dose of vaccine to all senior citizens so that mortality can be reduced,” points out Arun N.M., an Internal Medicine consultant, Palakkad.
A significant proportion of the 60-plus group in Kerala has not even taken the first dose because they are confused or hesitant. Dr. Arun feels that the frenzy over more younger people dying of COVID-19 should be taken with a pinch of salt.
“The majority of the deaths are still in the older group, though the proportion of deaths in the younger age group has also risen, in proportion to the rise in cases. Just like the U.K., we should also adapt our guidelines in tune with emerging evidence,” he says.
