Covid Booster Shots Can Significantly Increase Immunity, According To A Trial

According to a study, Covid booster shots can significantly improve the body's immunological defenses, raising hopes of preventing another wave of severe sickness caused by the Omicron strain.

Researchers from the UK-based Covid-Boost trial examined immune responses in over 3,000 participants who got one of seven Covid-19 boosts or a placebo two to three months after their second dose of either AstraZeneca or Pfizer vaccination, according to a report published in the Lancet.

After two doses of AstraZeneca, those given Pfizer had antibody levels roughly 25 times greater than controls a month later. Antibody levels increased by more than eightfold when the Pfizer booster was administered after two Pfizer doses.

A complete dosage of the Moderna vaccination was the most effective booster in the study, raising antibody levels 32-fold in the AstraZeneca group and 11-fold in the Pfizer group. Moderna is given in half-doses in the United Kingdom's booster program.

While the results suggest that both the Pfizer and Moderna mRNA vaccines are highly effective boosters, doctors cautioned against comparing their results because participants began with differing antibody levels. Antibody levels, for example, tend to stay high for several months after a Pfizer immunization, so a booster wouldn't be able to push them much higher.

Prof Saul Faust, the trial's lead and director, said, "These are very effective immune boosters, much beyond what is needed to prevent hospitalization and death."

Prof Saul Faust, trial head and director of the NIHR clinical research centre at University Hospital Southampton NHS Foundation Trust, said, "These are very effective immune boosters, much above what is needed to prevent hospitalisation and death." The majority of people who reported side effects had fatigue, headaches, or arm pain, and the study found no safety concerns.