Vaccine for covid-19: India’s first nasal vaccine against COVID-19: How do nasal-spray vaccines work?

                           
The nasal vaccine from Bharat Biotech has been licenced by the Central Drugs Standard Control Organization for primary immunisation against COVID-19 in the 18+ age group for restricted use in an emergency, according to a tweet from Union Health Ministry on September 6.

 
The vaccine for covid 19from Bharat Biotech, which will be nasally administered and was created in collaboration with the University of Washington, is expected to prove an effective weapon in the fight against the virus by preventing infections, something the other vaccines have not been able to do.

What is a nasal vaccine?

Vaccination can be administered via a variety of techniques. The most popular vaccine is the intramuscular shot, which is administered directly into the muscle. Vaccines administered subcutaneously transmit the dose between the skin and the muscles.

In the case of polio drops, vaccines can also be given orally. In contrast, the shot in a nasal vaccine is sprayed into the nostrils and inhaled.

A nasal vaccine is one that is given to a person through the nose without the use of a needle. By targeting the virus at its point of entrance, the infection may be prevented from entering the host.

How do nasal vaccines work?

The B cells in the blood begin producing antibodies when a vaccination is given to the human body. IgG antibodies are the most significant of them. They look for the virus within the body and use T cells to kill the infected cells.

But B cells are also seen near the mucosal tissues. They produce IgA antibodies when a nasal vaccination is delivered. Only the pathogens in the airway are destroyed by IgA and T lymphocytes. Additionally, they memorise the pathogen to keep it from ever reentering the body.

Why nasal vaccines might be more effective?

They are injected into the muscle, which is one reason. Intramuscular injections trigger an immune response that comprises B cells, which make antibodies that 'neutralise' pathogens by attaching to them and preventing them from accessing healthy cells, and T cells, which kill infected cells.

The bloodstream carries these cells and antibodies. However, the nose and lungs do not have them in sufficient quantities to quickly offer protection. 

The virus spreads and the infected person becomes ill during the time it takes for the particles to travel there from the bloodstream.

The effectiveness of mucosal vaccinations as initial doses for the unvaccinated and as boosters for those who have already received COVID-19 shots is being studied by researchers. 

Some mucosal vaccines are administered up the nose as liquid or droplets and are the same as vaccines that are injected. Others are cooked differently or have a different composition. 

For instance, the CanSino mucosal vaccine is identical to its injectable counterpart, but it is packaged as aerosols and administered orally using a nebulizer at a dose that is one-fifth that of the injected vaccine. Several in-development mucosal vaccinations are taken orally as pills.

                             Source: Indian Express

Side effects of Nasal Vaccine

The effectiveness of mucosal vaccinations against other illnesses has not been great. It frequently fails to elicit a strong enough immunological response. It might also result in negative effects.

However, it also noted that research had indicated that mucosal vaccinations could stop infection and transmission in some animals.

Nasal Vaccine in India

The two-dose main inoculation, rather than a booster dosage, of India's vaccine, which was created by Bharat Biotech in Hyderabad, is accepted.

The business has created "viral vector" vaccinations that introduce SARS-CoV-2 genetic material into host cells using a non-lethal adenovirus. 

Although both companies assert they have finished these investigations, neither has released phase III clinical trial data.

There are mucosal vaccinations available for cholera, influenza, and other infections as well. All but one of these vaccine for covid 19immunizations are administered orally, including the flu vaccine.


Written By: Manisha Nair