The booster dose is being given six months after the trial participant received the second dose of the vaccine. The efficacy of the two doses of the vaccine is likely to last at least nine months, and the booster dose is expected to increase the immune response further.
The volunteers part of the phase two trial had received both the doses of Covaxin in March, and are being given the third dose after the passage of six months. said Dr Sathyajit Mohapatra, lead researcher of Covaxin trials in SRM Medical College and Research Centre.
“The analytics are yet to be done but booster doses are expected to improve the immune response in these volunteers,” Dr Mohapatra said.
Research suggest that while antibodies sustain in many individuals who have received the vaccine doses, it might not be the same in some people as the efficacy of the vaccine might reduce and the antibodies would not sustain beyond 6-9 months. Thus, the trial is being conducted to establish the effect of third dose of Covaxin on individuals who have received both the doses of the vaccine.
“The trial is being done on a small scale to understand if the booster doses are efficient and help in improving the immune response. Another trial with a large sample size will be helpful in getting better results. The participants are being followed up, and there are no adverse effects in any of the volunteers so far,” added Dr Mohapatra.
