New Delhi: In a new study published in the Lancet journal, it has been suggested that the Pfizer vaccine for COVID is considerably less effective against the Delta variant of COVID, which is prevalent in India, than the original Coronavirus strain.
The study further states that antibody response to variations is even lower in persons who have only received one dosage, and the data suggest that a longer gap between treatments could dramatically reduce antibodies against the Delta variation.
After a single dose of Pfizer, 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 or Alpha variant, 32 per cent for Delta and 25 per cent for the B.1.351 or Beta variant first discovered in South Africa. The researchers note it is most important to ensure that vaccine protection remains high enough to keep as many people out of hospital as possible, a news report published by NDTV said.
UCLH Infectious Diseases consultant and Senior Clinical Research Fellow for the Legacy Study, Emma Wall as per the news item said, “Our results suggest that the best way to do this is to quickly deliver second doses and provide boosters to those whose immunity may not be high enough against these new variants.”
The recommendation contradicts India’s recent decision to prolong the duration between two Covidshield doses from six to eight weeks to 12 to 16 weeks, citing studies that showed the vaccine’s effectiveness improved with time.
Quoting critics, the report said that GoI is expanding the gap to relieve pressure on its immunization campaign, which has been hampered by a lack of doses and a restricted supply of vaccinations.
Explaining the position of GoI, the report quoting sources in the GoI said: “Available real-life evidence particularly from the UK that effectiveness was significantly higher at 81.3 per cent (60.3-91.2) after two doses given at an interval of 12 weeks or longer, compared to 55.1 per cent (33-69.9) when given less than six weeks apart. That study was, however, not based on the Delta variant.
The latest Lancet study, on the other hand, backs up the current UK plans to close the vaccine dose gap, finding that after just one dose of the Pfizer-BioNTech vaccine, people were less likely to develop antibody levels against the Delta variant than the previously dominant Alpha variant, which was first discovered in UK’s Kent.
Furthermore, while emphasizing the excess risk created by the Delta variant the item stated, “UK’s Public Health England (PHE) says experts believe the Delta variant has overtaken the Alpha strain in the country and early evidence suggests there may be an “increased risk of hospitalisation” with the Delta strain compared to the Alpha.”
According to the Lancet, Pfizer-vaccination BioNTech’s generates five times fewer antibodies against the Delta variation than the original Covid strain.