2ND JAB KEY
not the strongest known. Even the MRNA vaccines struggle against the resistant variants when given only once,” said John P Moore, virologist and professor at Cornell University’s Weill Cornell Medicine.
On May 13, India announced that people on Covishield (the India-made version of the Oxford-astrazeneca vaccine) need to wait 12-16 weeks for their second doses, citing real world data from UK that showed improved efficacy when the gap between shots was expanded.
But on May 15, the UK itself reduced the gap from 12 weeks to 8 weeks and accelerated rollout to more groups, citing the B.1.617 variant. Jameel added that it might be too soon to determine if the extended dosing schedules pose a risk.
The B.1.617 is a variant with three sub-lineages – B.1.617.1, B.1.617.2 and B.1.617.3. Among these, whole genomic sequencing has shown that B.1.617.2 has grown rapidly in several parts of the world, including India, UK and US.
According to an updated analysis by outbreak.info of data on the global repository GISAID, 58% of the samples sequenced in India over the last 45 days are of this variant, which now appears to have become dominant after rising from relative obscurity in midmarch. Along with B.1.617.1, the B.1.617 lineage now accounts for 70% of the samples analysed in the last 45 days.
Moore added that the data from UK reinforce what has been observed in lab analysis. “I am not surprised by the reports from the UK.
The B.1.617 variant is known to have a set of mutations associated with antibody resistance, and assays in a UK lab (Gupta in Cambridge) confirm that. It’s a set of mutations not any individual one that’s responsible,” he said.
In an interview to Global News, the CEO of Biontech, Ugur Sahin said on May 20 that he expects the Pfizer-biontech
MRNA vaccine have around 70-75% efficacy in preventing infection of the B.1.617 variants. While this is lower than the 95% protection from the variant that was first seen in Wuhan, experts said vaccines are likely to still offer significant protection from severe illness.