New Delhi: A study in the Lancet journal said that two doses of Pfizer-BioNTech provide five times fewer antibodies against the ‘Delta’ variant of COVID-19 than against the original variant. The research added that the levels of these antibodies decreased in elderly subjects.
Researchers also said that the antibodies decreased over a period of time.
This provides additional evidence in support of plans to inoculate the vulnerable sections of the population with a third booster dose.
The research team led by experts from the Francis Crick Institute also supported the United Kingdom’s government to reduce the gap between the two doses of the vaccine.
They stated that after the first dose people were less likely to develop antibody levels against the Delta variant as compared to the Alpha variant.
250 healthy people were analysed for the presence of antibodies for up to three months after their first dose of vaccine.
The researchers then tested the capability of antibodies to block the entry of all COVID 19 variants into the cells.
Data which was incurred from these tests showed that people developed five times lower antibodies against the Delta variant as compared to the original variant.
In the case of people who had received only one dose the level of antibodies was even lower.
After a single dose of Pfizer-BioNTech, 79 per cent of people had a quantifiable neutralising antibody response against the original strain, but this fell to 50 per cent for B.1.1.7, 32 per cent for B.1.617.2 and 25 per cent for B.1.351 or Beta variant first discovered in South Africa.
“This virus will likely be around for some time to come, so we need to remain agile and vigilant,” said Emma Wall, an Infectious Diseases consultant at University College London Hospitals NHS Foundation Trust (UCLH). “Our study is designed to be responsive to shifts in the pandemic so that we can quickly provide evidence on changing risk and protection,” Wall said.
The researchers added that the government should inoculate people with the second dose as soon as possible and should also provide a booster dose to the vulnerable sections to keep the spread of the pandemic in check.