It’s not clear what that means for long-term immunity, they added. “We demonstrate that both approaches generate high levels of antibody response but peak values are 3.5-fold higher with the extended-interval protocol,” Parry’s team wrote.īut the shorter, three-week interval produced stronger cellular responses, they said. Some researchers have argued that delaying the second dose of vaccine can be expected to produce a stronger immune response than a shorter interval. Britain initiated the delayed vaccine schedule to try to stretch a limited vaccine supply and get more first doses to more people. Helen Parry of the University of Birmingham and colleagues studied 172 volunteers 80 and older who got Pfizer/BioNTech’s coronavirus vaccine either as the company recommends – two doses given three weeks apart – or on a delayed schedule of two doses given 12 weeks apart. The findings are published on a pre-print online server called medRxiv and have not been peer-reviewed.ĭr.
Fallon/AFP/Getty ImagesĪ small study of elderly people finds that delaying a second dose of the Pfizer coronavirus vaccine for three months produces an even stronger antibody response than giving it on the recommended schedule of three weeks after the first dose.īut it’s not clear whether that translates into stronger protection in real life – and the delayed vaccination schedule resulted in lower levels of immune system cells that are involved in long-term protection from disease, the researchers in Britain reported. Vials of the Pfizer Covid-19 vaccine are seen at a mobile vaccination clinic at the Weingart East Los Angeles YMCA on May 14 in Los Angeles.