Nasal vaccines a gamechanger, can block virus at entry site: Expert

By Express News Service
Nasal vaccine will be a gamechanger, best suited for vaccinating children against Covid-19. A single dose will suffice to stimulate the immune response, and there will be no hassle of taking an injection, Dr Rajinder Kumar Singal, senior director and HOD-internal medicine, BLK Max Hospital, Delhi, said during a panel discussion on ‘Covid-19: Lessons Learnt and Planning Forward’.

“In six to eight weeks, we expect nasal vaccines to be available. They will be cheaper and will block the entrance site of the virus,” said Dr Singal.Agreeing with him, Professor and Padma Shri awardee Dr Mohan Kameswaran, Otorhinolaryngologist, founder, Madras ENT Research Foundation, Chennai, said nasal vaccines are ideal for India, where vaccine hesitancy is largely connected to getting an injection.

Doctors on the panel agreed that a booster dose will be needed against the coronavirus. This was confirmed through the results of a study done by Neuberg Diagnostics. Sharing details, Dr Bhavini Shah, director, Neuberg Centre of Genomic Medicine, Ahmedabad, said they tested antibody levels in people who did not get Covid before taking the vaccine, one month after taking the first dose, one month after the second dose, and three months after the second dose.

“In 40 % of the people who had never been infected by Covid, IgG antibody titres increased to 75-95 AU/ml range one month after taking the vaccine, after taking the second dose, the titres ranged between 175 and 200 AU/ml. However, after three months, it dropped from 200/190 AU/ml to 120. In those who had Covid-19, the antibodies were above 400 AU/ml. This indicates the need for a booster dose,” Dr Shah said.

Both Dr Kameswaran and Dr Hemalata Arora, general physician and infectious disease specialist, Nanavati Max Super Speciality Hospital, Mumbai, said the chances of people developing mucormycosis (black fungus) post taking the vaccine, are lower.“60 per cent to 70 per cent of the patients who came to me with black fungus had not taken the vaccine, 25-30 per cent had taken one dose and less than 5 per cent had taken both doses. Thus, people who have taken both doses have a good chance against Covid-19 infection, and are much less prone to black fungus,” Dr Kameswaran said.

Dr Arora said the antibodies produced by the vaccine protect against Covid, complications, side-effects, blood clotting, secondary infections and mucormycosis too. “There are studies being done on using mRNA vaccines for booster doses rather than taking the same DNA vaccines we took the first and second time. Mixing might be more appropriate, though there may be some side-effects,” Dr Arora added.