1 / 8Those who have taken the booster dose of the COVID-19 vaccine cannot take Bharat Biotech’s nasal coronavirus vaccine– iNCOVAAC, head of India’s coronavirus task force group National Testing Advisory Group (NTAGI), Dr. NK Arora, said.2 / 8He mentioned that the nasal vaccine can be used as a first booster while adding the indigenously developed CoWIN platform will not accept bookings for a fourth dose. 3 / 8But is taking the fourth dose of the COVID-19 vaccine of any help? Dr. Arora says a phenomenon known as antigen sink kicks in when a person is repeatedly vaccinated with a particular type of antigen as the body either stops responding or responds poorly.4 / 8He further tells NDTV that this is exactly why initially mRNA vaccines are given with a gap of six months, which was later reduced to three months.5 / 8When asked whether people have to take a precautionary dose after getting the booster doses of the nasal vaccine, the NTAGI boss said, “The scientific answer is at the moment there is no evidence that further vaccines will be required or not required. Even in countries where people have taken three, four or five doses of vaccine, particularly mRNA vaccines in North America and Europe, but they continue to suffer from the infection.”6 / 8Since the entry point of a nasal vaccine is the nose and mouth, it is not only going to help in tackling COVID-19 but also other respiratory viruses and infections, as per Dr. Arora.7 / 8Anybody aged 18 years and above can get the iNCOVAAC nasal vaccine and four drops have to be administered in each nostril.8 / 8Dr. Arora also claims the nasal vaccine is completely safe and merely causes nasal blockage for a short period of time.Those inoculated will be kept under observation for 15-30 minutes to see if there are any adverse effects just like any other vaccine.