India’s first intranasal vaccine, iNCOVACC (BBV154) has been approved for primary inoculation by Central Drugs Standard Control Organisation (CDSCO). The vaccine was manufactured by Bharat Biotech and was developed by scientists at the Washington University. iNCOVACC becomes the first intranasal COVID-19 vaccine for emergency use in India and would be used for primary immunisation against COVID-19 among the 18+ age group. It could be an option for children as two vaccines were authorised for use in the 5–12 and 6–12 age groups in April, and there is no sign of a rollout for these candidates. The intranasal vaccine was supported by the Department of Biotechnology (DBT) and Biotechnology Industry Research Assistance Council (BIARC) under the aegis of ‘Mission COVID Suraksha’, launched by the DBT. Thus, it is the fourth success story for the COVID-19 vaccine.
Now, the government would have to formally decide to include it in the national COVID-19 immunisation programme. Early publication of the trial data and a speedy rollout of the nasal vaccine would be ideal as it might be more appealing to people who have not yet been vaccinated.
Significance of the Vaccine
iNCOVACC intranasal vaccine has paved the way for access to a new method of inoculation. According to scientists, the vaccine could significantly boost protection from COVID-19 for the population, helping stop not just the disease but also new infections to a great extent.
The vaccine uses a harmless version of the Chimpanzee Adenovirus Vectored (ChAd36-SARS-CoV-S COVID-19) to deliver the spike protein to the lining of the nose.
Unlike conventional vaccines, shot in the muscles, nasal vaccines are a crucial breakthrough to end the pandemic. Conventional vaccines trigger antibodies that circulate in the bloodstream and are best suited for preventing the disease from taking hold, but they are usually unable to avert an infection of transmission. On the contrary, intranasal vaccines target the mucous membrane in the nasal pathway, the site where the SARS-CoV-2 first infects the human body. Intranasal vaccines bring about a protective coat of IgA antibodies over the mucous membrane, and help prevent the infection from taking hold in the first place. This coating of IgA is called sterilising immunity, which prevents the virus from causing infection effectively. [Immoglobulin A (IgA) is an antibody which immunises mucous membrane.]
iNCOVACC would have the double benefit of enabling faster development of variant-specific vaccines and easy nasal delivery that enables mass immunisation to protect from emerging variants of concern. This vaccine would prove to be an important tool in mass vaccination during pandemics and endemics.
According to Bharat Biotech, iNCOVACC would remain stable at 2 °C–8 °C for easy storage and distribution.
Evaluation and Trials
Immunogenicity was evaluated through serum neutralising antibodies by plaque reduction neutralisation test (PRNT) assays and serum IgG’s through enzyme-linked immunoassays (ELISAs). IgA’s were evaluated by ELISA in serum and saliva. Evaluation was also carried out to test out the ability of iNCOVACC to elicit long-term memory T and B cell responses against the ancestral and omicron variants.
According to the University of Washington article, the two clinical trials of iNCOVACC were conducted in India. A phase 3 trial, involving about 31,000 previously unvaccinated people, were given two doses of the nasal vaccine. Also, a booster trial dose was given to about 875 people who had received a single dose of the nasal vaccine after two doses of another COVID-19 vaccine. These trials were concluded in August 2022—the vaccine was found to be safe and effective at eliciting a strong immune response in people when used either as a primary vaccine or a booster.
According to Bharat Biotech, the reactogenic events and adverse events that were documented during the trial were highly comparable to the published data from other COVID-19 vaccines. Product development data would be submitted to peer reviewed journals and would be made available in the public domain.
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