Covid19 : Eight – week gap between doses of the Pfizer vaccine seem to produce more antibodies
An interval of eight to ten weeks between doses of the Covid-19 vaccine developed by Pfizer Inc. and BioNTech SE boosts the effectiveness of the two-shot regimen compared with a shorter interval, a U.K. study found.
“Eight weeks is probably the sweet spot,” in terms of the trade-off between getting as many people fully vaccinated as quickly as possible and allowing the population to produce higher antibody levels, professor Susanna Dunachie, the study lead from the University of Oxford, said at a briefing Thursday.
The UK initially extended the dosing gap to 12 weeks at the end of 2020. But as the vaccination programme has been rolled out through the age groups – everyone over 18 has now been offered at least their first jab – people have been encouraged to bring their second jab forward and get it after eight weeks.
The scientists found that after the second dose, a wider gap also resulted in higher neutralising antibody levels against the Delta variant and all other variants of concern.
But in this instance, antibody levels dropped off between first and second dose – leaving the recipients vulnerable against the Delta variant after one jab.
The study looked at the immune response in 503 U.K. healthcare workers, about three-quarters of whom were women. It was funded by the U.K.’s Department of Health and Social Care and conducted by scientists from the universities of Oxford, Newcastle, Liverpool, Sheffield and Birmingham, with support from the U.K. Coronavirus Immunology Consortium.