Indian nasal Covid vaccine can be potential gamechanger: Experts

Several studies have proved that the clinical efficacy of intranasal vaccine is superior to that of injectable vaccine. In India, Hyderabad-based Bharat Biotech has sought Drugs Controller General of India's (DCGI) approval to conduct clinical trials of its nasal vaccine for coronavirus.

Last month, Pune-based Serum Insititute of India and Codagenix Inc had announced that they have received regulatory approval in the United Kingdom to begin an early-stage trial of their single-dose, intranasal coronavirus vaccine.

"At the moment, four vaccines are undergoing phase 1 and 2 of nasal vaccine trials in the world. It can be a gamechanger but it all depends on whether it is safe and effective," said Lalit Kant, former head of epidemiology and infectious diseases at the Indian Council of Medical Research (ICMR).

Alluding to the advantages of the nasal vaccine, he said its administration does not require syringes, and it is easy to administer, transport and store. "You can immunise a larger number of people in a small amount of time. There would be no need for people to come back for a second dosage," the noted epidemiologist said.

"It is a live attenuated vaccine. When you give it through the nose, there is the mucous membrane in the upper throat, where it gets absorbed and is able to develop the antibodies. Since it enters the mucous member directly, the absorption is faster," Kant said.

According to Bharat Biotech, an intranasal vaccine stimulates a broad immune response at the site of infection, in the nasal mucosa, which is essential for blocking both infection and transmission of Covid-19.

"Intranasal immunisation of can create an immune response in the nose, which is the point of entry for the virus-thereby protecting against disease, infection, and transmission," the firm said in a statement.

Anish Sinha, Associate Professor at the Indian Institute of Public Health, said that intranasal vaccine can be a gamechanger, particularly in countries which have logistical issues. "The ease of administration will be the biggest advantage. It can be utilised in larger numbers with lesser operational challenges," he added.

Meanwhile, On January 3, two intramuscular vaccines - Bharat Biotech's 'Covaxin' and Oxford-AstraZeneca's 'Covishield' manufactured by Serum Institute of India - were approved for restricted emergency use. These are two-dose vaccines.