A large study of people across England found strong antibody protection in people who got both doses of the Pfizer/BioNTech vaccine – but people who had been infected and got just a single dose had even stronger responses.
The REACT-2 study by scientists at Imperial College London found that three weeks after receiving the first dose of the Pfizer/BioNtech vaccine, 84% of people under the age of 60 tested positive for antibodies against SARS-CoV2.
Among those who had received one dose but had suspected or confirmed prior infection with Covid-19, this rose to 90%.
“We have found a really good response, measured by antibody prevalence, in those who have had two dose of the vaccine and those who have had one dose,” Helen Ward, professor of Public Health at Imperial College London, told reporters at a news conference. “I hope this will be used to encourage people get their second dose.”
“There’s clearly value in getting that first dose,” added Graham Cooke, professor of Infectious Diseases at Imperial College London. “We don’t have enough data yet on the long-term protection of one dose.”
The study of 155,000 people tested between Jan. 28 and Feb. 8 covered 18,000 vaccinated people, including 13,000 who got the Pfizer vaccine.
The findings paint a picture of which groups had been most affected by coronavirus during England’s second wave. Infections were highest in people living in London (16.9%). More than 22% of people of Black ethnicity appeared to have been infected and 20% of people of Asian background had. Just 8.5% of Whites had evidence of having been infected.
Concerns around vaccine confidence were also raised, being more common among younger people and Black people. Reasons for low confidence included worries about pregnancy, allergies and fertility, the study found.