Since new variants of coronavirus will keep coming, booster doses will be required to control the pandemic, according to Priya Abraham, Director of the National Institute of Virology (NIV), Pune, under the Indian Council of Medical Research (ICMR). NIV had spearheaded development of India's first indigenously developed vaccine, Covaxin.
Studies on booster dose have been going on overseas and at least seven different vaccines have been tried out for booster dose. Now, the World Health Organization (WHO) has put a stop to it till more countries catch up with vaccination as there is an alarming vaccine gap between high-income and low-income countries. However, in future, recommendations for boosters will definitely come, she said.
Wearing mask properly and actively encouraging everyone to get vaccinated is the solution and even if a new wave comes, it will not be a big one. The Delta-plus variant is less likely to spread than the Delta variant itself. The highly transmissible Delta variant is present in over 130 countries.
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"We have studied the antibodies produced in the bodies of vaccinated people and checked it against this variant. It has been found that efficacy of antibodies against this variant has been reduced two to three folds. Yet, the vaccines are still protective against the variants," she said in an interview with India Science, the OTT channel of the Department of Science & Technology.
She said India is likely to have COVID-19 vaccines for children by September or just after. Presently, Phase II and III trials of Covaxin are going on for children in the age group of 2-18 years. Zydus Cadila’s vaccine trial is also going on for children.
Commenting on mixing of vaccines, she said there was a situation where inadvertently two different vaccines were given in two doses. NIV tested those samples and found that the patients who received different vaccines in two doses were safe. No adverse effect was noted and immunogenicity was a little better. "It is definitely not something which will cause a safety issue. We are studying this phenomenon and will be able to give more details in a few days’ time," she said.
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Priya Abraham and her team were among the first in the world to isolate Covid-19 virus and gave the strain to Bharat Biotech International Limited (BBIL) by the end of April last year. With that BBIL developed a whole virion-inactivated vaccine in a month and gave back to NIV for review.
After ensuring complete inactivation of the virus, studies were done for complete characterisation and pre-clinical trials were started on hamsters and non-human primates (monkeys). All tests were done in NIV's highest Bio-Safety Level-4 level containment facilities and in the next phase, NIV assisted BBIL in the Phase I, II and III clinical trials in areas such as diagnostic aspect and laboratory support, she said.
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