Pfizer Covid-19 jab produces less antibodies against Delta variant: Lancet

People fully vaccinated with the Pfizer-BioNTech vaccine are likely to have more than five times lower levels of neutralising antibodies against the Delta variant first identified in India compared to the original strain, according to research published in The Lancet journal.
 
The study also shows that levels of these antibodies that are able to recognise and fight the virus are lower with increasing age, and that levels decline over time, providing additional evidence in support of plans to deliver a booster dose to vulnerable people.
 
It supports current plans in the UK to reduce the dose gap between vaccines since they found that after just one dose of the Pfizer-BioNTech vaccine, people are less likely to develop antibody levels agai­nst the B.1.617.2 variant as high as those seen against the previously dominant B.1.1.7 (Alp­ha) variant, first found in Kent.

 

The team, led by researchers from the Francis Crick Institute in the UK, noted that levels of antibodies alone do not predict vaccine effectiveness and prospective population studies are also needed. Lower neutralising antibody levels may still be associated with protection against Covid-19, they said. The study analysed antibodies in the blood of 250 healthy people who received either one or two doses of the Pfizer-BioNTech Covid-19 vaccine, up to three months after their first dose.
 
The researchers tested the ability of antibodies to block entry of the virus into cells, so called 'neutralising antibodies', against five different variants of SARS-CoV-2.

 
They then compared concentrations of these neutralising antibodies between all variants.
 
Data from previous clinical studies suggests that higher antibody titres or concentration is a good predictor of vaccine efficacy and greater protection against Covid-19.
 
UK authorises Pfizer vaccine for use in adolescents
 
The UK drugs regulator authorised the vaccine from Pfizer and BioNTech SE for use in 12- to 15-year-olds as a num­ber of countries move to inocul­ate children. Britain’s Medicines and Healthcare products Regu­­­latory Agency said it extended the approval of the vaccine down to adole­scents after conclu­ding the shot had a posi­tive safety profile in this age group.