BOOSTER SHOTS
We are not talking enough about variants — at least not enough of the right kind of talk. Sure, the government was perturbed enough by repeated references to the B.1.617.1 and .2 mutations of the SARS-COV-2 virus as the Indian variants (everyone, including various government departments had no problems with referring to a prior mutation as the UK variant) to put out a statement that effectively beseeched everyone not to refer to them as such. But no one knows for sure whether these variants are responsible for the surging second wave of the coronavirus disease that India saw through March and April because there hasn’t been adequate sequencing of the viral genome. More aggressive sequencing, especially in hotspots such as Delhi and Bengaluru could have shed light on this, and added to our understanding of the current trajectory of the pandemic in India — vital in managing both the present and the future.
In the absence of this, what we do have are uploads from India to the GISAID database. There’s no way of knowing whether this is a representative sample, but B.1.617.2 accounted for 46% of sequences from India uploaded to the database between March 1 and April 30; and B.1.617.1 another 19%. That means two of three of the genomes uploaded on the database were of the variants. It stands to reason that they have become the dominant strains of the virus in India.
It isn’t clear how this data can be compared with that mentioned by the head of India’s National Centre for Disease Control who said recently that genome sequencing data from INSACOG (the Indian SARS-COV-2 Genomic Consortia; a grouping of 10 laboratories) showed that of the 18,053 samples sequenced since December, 3,532 were so-called variants of concern.
Adding to what we know is yet-to-be-peer-reviewed research by scientists from India and the UK, including those at INSACOG, the COG-UK consortium, NCDC, Cambridge University and the CSIR Institute of Genomics and Integrative Biology. The research notes that of 33 infections of vaccinated healthcare workers in a hospital, the majority were of B.1.617.2, although none of these was a severe infection. Importantly, and this aspect merits repetition and highlighting, the authors argue that the family of B.1.617 variants may have “a modest ability” to be resistant to antibodies caused by infections of the original virus Wuhan-1 D614G. Their hypothesis is that 20-50% of the Indian population (based on various sero- or antibody-surveys) was infected with that original strain and had antibodies, but that because the new variants were resistant to these antibodies, this may have “likely contributed to an epidemic wave” in the country.
That the emergence of these variants coincided with the complete easing of restrictions on movement and activities across India, a collective lowering of the guard, and several super-spreader events did not help. Nor did the country’s slow pace of vaccination. To date, just around 140 million Indians have received at least one dose of the vaccine. That translates into 15% of the eligible population.
The researchers also point out that while the variants were resistant to antibodies (created either naturally or through vaccination) to some extent, the “progression to severe disease and deaths” was low in the case of anyone with any prior protection. They conclude that “extensive vaccination will likely protect against moderate to severe disease and will reduce transmission.”
Interestingly, although there is no data to bear this out, some experts are of the opinion that maintaining the gap between the first shot and the second (or booster) shot of the Astra/zeneca-oxford vaccine (sold as Covishield in India) to eight weeks could help combat the variants. The UK, which initially increased the gap to 12 weeks based on research that showed the vaccine’s efficacy increasing after that period (Spain has extended it to 16 weeks based on the same logic), has now reduced the gap to 8 weeks to manage a mini-surge in infections caused by the variants. Interestingly, the UK decision came around the same time as India’s to increase the gap to between 12 and 16 weeks (from the previous 6-8 weeks). Then, India’s challenge, given the supply-crunch in vaccines is to vaccinate as many people as possible and increasing the gap between doses of the most widely used vaccine in the country is a good way to do that.
In the UK, 69% of those eligible for vaccines have received at least one shot and 38%, both.
In India, 15% have received at least one dose and 4.4%, both.
Some experts are of the opinion that maintaining the gap between the first shot and the second (or booster) shot of the Astra/ Zeneca-oxford vaccine (sold as Covishield in India) to eight weeks could help combat the variants.