The fourth dose of Pfizer’s or Moderna’s COVID-19 booster vaccine is safe and raises antibody levels more than the third shot, according to the latest results from a nationwide study in the UK.
A fourth dose of coronavirus jabs have been introduced in Britain as a spring booster for the most vulnerable, researchers said. He added that it is a precautionary strategy to maintain a high level of immunity before the study data becomes available.
The study, published in The Lancet Infectious Disease journal, shows that a fourth-dose mRNA booster vaccine for the virus is well tolerated in people who received Pfizer as a third shot.
They are also effective in increasing both antibody and cellular immunity to baseline and above, and the peak levels seen after the third dose booster, the researchers said.
Professor Saul Faust, trial lead and director of the NIHR Southampton Clinical Research Facility, said: “These results underscore the benefits of the most vulnerable people receiving current spring boosters and give confidence to any potential autumn booster program in the UK, If the Joint Committee on Vaccination and Immunization considers that it is needed at that time.”.
In the findings, nearly 166 people who received a third dose of Pfizer after an initial dose of Pfizer or AstraZeneca in June last year were randomized to receive either Pfizer or a half-dose Moderna as a fourth shot.
The fourth jab was administered approximately seven months after the third shot.
Researchers said pain and fatigue were the most common side effects at the COVID-19 vaccination site, but there were no serious vaccine-related adverse events and the fourth dose was safe and well tolerated.
“We knew it was important to give a fourth dose of the year to the most vulnerable,” said Professor Andrew Ustianovsky, the NIHR clinical lead for the COVID-19 vaccination program.
“These new study findings support that decision and provide the public with confidence that the fourth dose is safer and more effective in boosting immunity against COVID-19 than the third dose,” Ustianovsky said.