All about iNcovacc, the intranasal Covid-19 vaccine of Bharat Biotech
The world’s first intranasal vaccine, christened as iNcovacc, is based on a delivery vehicle, a virus, that causes the common cold (adenovirus vector). The spike protein on the virus is the one that attaches to human cells to infect them. The spike protein on the vector is stabilised with appropriate changes, for a stable form at delivery, which is more effective in producing immunity or resistance to a virus.
It is different from Covaxin as the latter is an inactivated (killed) vaccine administered through intramuscular injections. It will be delivered as nasal drops, not as a spray, and to be given as four drops/each nostril, a total of 8 drops in a slow drip process of delivery, rather than a single shot/spray.
Who is its target user group?
iNcovacc is indicated for primary two-dose schedules, as heterologous and homologous booster doses and has been approved by the Government. In homologous boosting, a person is injected with the same vaccine that was used for the two previous doses. In heterologous boosting, a person is injected with a different vaccine from that which was used for the primary dose. While the primary dose is for first-timers, the booster dose is a precautionary or third dose. However, as of now, CoWin lists it only as a booster dose. So, all those who had been vaccinated with two doses already can use this as a booster dose.
How does the pricing of iNcovacc compare with other Covid vaccines available in India? Will it be provided free of cost at government healthcare facilities?
The vaccine has been priced at ₹800 per dose for private healthcare providers and ₹325 per dose for governments, excluding 5 per cent GST. Comparatively, Corbevax of Biological E costs ₹250 per dose at private vaccination centres while Covishield of Serum Institute and Covaxin of Bharat Biotech are priced at ₹225 per dose at private health facilities. In the public immunisation programme so far, vaccination is provided free of cost at Government hospitals.
What is the efficacy of the nasal vaccine? Is it as potent as the vaccines administered through injection?
In terms of efficacy, intranasal vaccines are more efficacious than intramuscular ones, according to experts. This vaccine candidate was evaluated in phases I, II and III clinical trials with successful results. iNcovacc recipients demonstrated significant levels of Mucosal IgA antibody levels (measured in the saliva). Mucosal IgA antibodies in the upper respiratory tract may provide benefits in reducing infections and transmission.
How have nasal vaccines been received in countries where they have already been introduced?
Two needle-free Covid vaccines that are delivered through the nose or mouth have been approved for use in China and India so far. The data pertaining to China is not available while in India their use is yet to begin.
Are there any other modes of administering covid vaccines besides these two?
Apart from nasal and intramuscular injections, Covid vaccines are also administered into the dermis (inner layer of the skin) – located between the epidermis and the hypodermis – using a needle-free applicator.