A NEW study has revealed that 96.42 per cent of people who received of dose of Covid-19 vaccine had developed antibodies after 28 to 34 days. That rose to 99.08 per cent within seven to 14 days of the second jab.
The findings are based on a study of 8,517 people in England and Wales who had one dose of the AstraZeneca or Pfizer vaccines. It also proves the efficiency of Britain’s vaccine drive, reported The Guardian.
Both vaccines were equally good at triggering the antibodies needed to fight off Covid-19, the researchers from University College London (UCL) found.
“This is one of the earliest real-world vaccine studies in the UK and it is fantastic news”, Dr Maddie Shrotri, the lead author of the paper containing the findings, told The Guardian.
“Over nine out of 10 adults in the UK who had either the Pfizer or AstraZeneca vaccine produced antibodies against the virus within a month of their first shot. How well these vaccines work is remarkable, especially given the speed at which they’ve been developed. It’s a real feat of science in the face of the most devastating pandemic in a century.”
According to the report, these conclusions are based on analysis of 13,232 antibody samples given by the participants in the trial, none of whom had antibodies before they had their first dose of vaccine.
The average age of the participants was 65, reflecting the older age groups who were the first in the UK to receive Covid vaccines under the NHS’s widely-praised programme that began on 8 December.
Antibody rates initially rise more quickly among those who have had the Pfizer/BioNTech vaccine than those with the Oxford/AstraZeneca one. However, after four weeks the recipients of either demonstrate almost identical antibody positivity rates, the newspaper report added.
The research found out that the vaccines stimulated the production of fewer antibodies in older people after one dose, than younger ones. But once everyone had had their second dose people of all ages enjoyed uniformly very high antibody levels.
"Antibody levels after one jab are also lower in people with some underlying health conditions, including cancer, diabetes and heart disease, and also those taking immune system suppressing medication, usually for cancer. However, again that difference disappeared once all participants had their second vaccine," researchers said.
Prof Rob Aldridge, the chief investigator of the UCL Virus Watch study, said: “The UCL Virus Watch data shows that for older adults and for people with underlying health conditions, the antibody response is a bit weaker after the first dose of the vaccine, but strong after the second dose.
“It is a timely reminder about the importance of getting the second dose of the vaccine. But it is also reassuring – vaccines are our way out of the pandemic.”
According to the authors of the report, everyone should have both doses of their vaccine so they can be considered 'safe', especially older adults and people with existing ailments.
More than 20 million Britons have now had two doses of either one of those vaccines, or the Moderna vaccine, which started being used in early April.
Anti-Racism protesters come out in support of refugees outside the Cladhan Hotel on September 13, 2025 in Falkirk, Scotland. (Photo by Jeff J Mitchell/Getty Images)
