Covishield does significantly better as a booster or third injection after primary vaccination with Covishield or Covaxin, according to a study from Christian Medical College, Vellore on boosting heterologous vaccines.
In an interview with Karan Thapar, microbiologist and professor at CMC, Vellore, Gagandeep Kang said that heterologous boosting with Covishield as the third injection after two doses of Covishield boosted antibody boosted the immune response 58-fold.
In an interview with The Wire, Kang said the study’s findings on mixing Covishield and Covaxin as a booster injection after being primed with either two doses of Covishield or Covaxin would be published this week. The findings of this investigation have already been submitted to the government.
They show that Covishield is a much more effective booster after two Covaxin shots than the other way around. So far, India has not allowed the heterologous boosting of vaccines. At this point, those who have taken two doses of Covishield should take that as the third injection and the same for those who have taken Covaxin.
Kang said, “If you’ve had two doses of Covaxin, you’d have a better immune response with a third dose of Covishield, and also, if you’ve had two doses of Covishield, you’d have a better response with Covishield. †
Kang, a member of the British Royal Society, confirmed that the CMC, Vellore study found that one third of Covaxin after two Covaxin antibodies increases the amount of antibodies six times, but from a very low base; a third Covishield after two Covishield raised antibodies 6.8 fold but from a much higher base; while a third Covaxin after two Covishield increases antibodies only 2.5 times. A third of Covishield after two Covaxin increases the antibodies 58 times, the study shows.
However, the expert also pointed out that although the Covaxin-primed and Covishield-boosted regimen starts to amplify the antibody response from a lower bar, people who received Covaxin as the primary dose and Covishield as the booster have been found to have better immunity. than those who received Covishield priming and Covaxin boosting.
Kang added that the CMC, Vellore study only tested antibody responses and not T cell responses. She also pointed out that no tests have been done with protein-based vaccines as boosters. The tests were limited to the two most commonly used vaccines in India, Covishield and Covaxin.
In fact, she said, “We can boost Covishield’s immune response with heterologous protein vaccine vaccination.” She also added that these data are comparable to data from elsewhere in the world showing that if someone received an inactivated vaccine as the primary two doses, a vector vaccine or an mRNA vaccine would give the immune response a better boost.
Nor did the expert sound concerned about people under the age of 60 and without any co-morbidities who did not immediately receive a third booster dose injection.
“We know that a booster dose gives an ascending level of immunity. Do most people under the age of 60 and without comorbidities really need a booster? Nowhere in the world is there evidence that a public health program will boost people under the age of 60 within the time frame that we have done, or perhaps others in the world have done. I think we have rushed to protect against a pandemic and in some cases we may have given too many doses too quickly,” she said in the interview.
She felt the time had come to redefine what we mean by wave, by focusing not on tests and test results, but on how many serious illnesses and deaths occur.