Nasal Vaccines for Covid-19: A ‘needle-less’ method of immunisation

As the world moves closer to recovery after recurrent waves of the Covid-19 pandemic, protection from the infection has become increasingly important in order to avoid any further spread in the community. While for many, vaccines are the first line of defence against infection, nasal vaccines have recently attracted a lot of interest for their incredible utility. 

What are Nasal vaccines?

Nasal vaccines are a breakthrough type of immunisation that may be given directly through the nose in the form of a liquid. These liquids can be administered via a syringe, dropper, or spray.

In a discussion with Amanda Starrantino from CBS News, Infectious Disease Specialist from Stanford Healthcare, Dr Abrar Carran said that these vaccines might be inhaled through the intranasal route and trigger an immune response in the mucosa of the nose instead of needing to be injected through an external muscular route, proving to be a much more convenient option for immunization against Covid-19. 

How are Nasal vaccines different?

While intramuscular vaccines are designed to support the immune system to produce some antibodies and other immune cells that are specific to the coronavirus in various locations throughout the body to fight the infection, they primarily aid in preventing serious illness, hospitalisation, or in the worst cases, death. Furthermore, it has also often been observed that sufficient immune cells aren't always produced in time, making it difficult for the immune system to keep up with the virus's quick multiplication within the body.

Nasal vaccines, on the contrary, are designed to prevent the infection from happening altogether, by essentially blocking the entry points of the virus in the nose itself, making them much more effective at stopping the disease from spreading.

In describing the utility of a nasal vaccine, Dr. Abrar Carran said, “The key point here is they may be better at preventing infection altogether. When you're walking around in the environment, you're exposed to pathogens in the air and you need to get enough for it to overcome your immune responses and cause clinical infection. The covid virus enters through your nose, through your mouth into your lungs and essentially if you can block that and get good immunity at the entry points, we hope that can prevent infection and we won't see the huge surges.”

How exactly do Nasal vaccines work?

By being administered directly in one’s nasal passage, nasal vaccines prevent the virus from spreading to the nasal mucosa, hence ‘hitting SARS-CoV-2 participles at the entry points’ as Dr Carran describes it. 

Similar to other vaccinations, nasal vaccines work to boost the immune system's capacity to fend off infection at the first sign of it. More crucially, however, they are known to make the mucosal immune systems in the throat and nose much more resistant to such threats, hence helping prevent infections from ever occurring in the first place. 

“We want people to have the immune responses start at the entry point so they don't get infected and spread it to other people. That's the key point. We don't want this to keep spreading,” Dr Carran remarked about the vaccines. 

How long until Nasal vaccines are available?

It should be noted that as of now there are no nasal vaccines available on the market.

However, in response to a question on the preparation of nasal vaccines, Dr Carran stated that clinical research to ascertain the usage and efficacy of nasal vaccines was still ongoing and that they could only be released into the market after they were declared safe for use. 

“We need to look at how people do in clinical trials, and what kind of immune responses people have. With any kind of vaccine, there's going to be an inflammatory response that some people have and need to monitor that just like we do for all vaccines and the comparison point is what happens if you don't get vaccinated and you instead get covid which induces an intense immune response and can cause worse effects and so with the intranasal vaccines we're going through clinical trials so we don't have an update in terms of big signals but once we do, it will be made available to the public,” Dr Carran said.

Dr Carran acknowledged, however, that the nasal vaccines may be made available to the general public by the end of this year or the beginning of the next one if the ongoing clinical trials provide promising results in terms of preventing infections and other serious ailments.