Why are nasal COVID-19 vaccines so talked about right now?
The availability of coronavirus vaccines has offered promising reassurances and safety against the SARS-COV-2 virus. As effective as they are, with newer, deadlier variants of the virus, the focus has now shifted to having more effective vaccines in place. Nasal vaccines, for one, are now strongly considered to be the newest shot of hope in our fight against coronavirus, with several vaccine developers working on the same. Hyderabad-based Bharat Biotech, the makers behind Covaxin are currently working on bringing out one such nasal vaccine shot, which could further strengthen the body's immune response against the virus.
(Image taken from AFP)
Nasal vaccines vs. Intramuscular vaccines: What we know
Even though the vaccines we do have right now have gone through a lot of clinical evaluations and have promising efficacy rates, several experts do believe that nasal vaccines- shots which are administered through the nose instead of the muscular route are far more effective in doling up an immune response against the infectious pathogen, or right now, add to the immune response generated via the vaccines in use right now. While they have been in development mode since last year, they are being promisingly looked on to as booster shots. We explain what makes them so special:
Could they be used as booster shots right now?
As per Dr Krishna Ella, Chairman and MD, Bharat Biotech, one of the reasons the company has greenlighted speedier trials and clinical study of its experimental nasal vaccine is for possible use as a booster shot. As per developers, the use and effectiveness of nasal vaccines, right now, when we have other vaccines in use is being studied as a standalone vaccine, but also as a booster shot. For example, Bharat Biotech is currently leading with trials of using its nasal vaccine dose as a follow-up to its two-dose intramuscular vaccine, Covaxin. Doing so, according to experts would prime the innate immunity in the body (via administration of two doses of Covaxin) and consequently, boost the mucosal immunity (present in the nose) as well as strengthen the iGG and IgA antibody immunity, which would protect against infection and cut chances of contracting the viral bug.
Similar approaches are also being tried out by other companies with their nasal vaccines. Certain studies done in Britain, for example, have also highlighted that nasal vaccine doses could effectively dole out a stronger and manyfold effective antibody response against the virus.
Now, while booster and additional shots of the COVID-19 vaccine are currently under review, and strongly advised for those who may be immunocompromised are a long shot, having nasal vaccine doses could cover up the issues, and make other intramuscular vaccines available for those who may need it more since a lot of countries are still in short supply. While more research is needed to back preliminary findings, nasal vaccines may also provide strengthened immune and antibody response, which may wane after vaccination.
Are there other benefits in place?
Apart from the clinically-backed and effective immune response, the usage of nasal vaccines is also something that has been advocated for a while. While nasal vaccines are easier to use and administer than routine vaccines, they may offer the advantage of easier facilitation, save up on resources, vaccine deliverables and with a little training, equip people to self-administer the vaccine shots as welll. This would considerably save up some of the costs and deliverables added to the cost of vaccination right now, and additionally, scale up the pace of vaccination as well.
Intranasal vaccines could also cover up some of the hurdles and problems being faced currently with some vaccines. Nasal vaccines are easier to store, transport and overall, an effective medium of vaccine delivery, which will help more people get a preventive shield against the deadly virus and its mutations.
Shortcomings to be aware of
While, on one hand, experts have suggested that intranasal vaccines are the closest to what natural immunity could feel like, and additionally, save up costs related to vaccine deliverables, there is a possible catch which does exist with the use of nasal vaccines, which is faster waning immunity, in comparison to other intramuscular vaccines, since they haven't been seen to be capable of mounting longer-lasting antibody response. Again, with all the promising positive signs, it should be remembered that while as experimentative as other COVID-19 vaccines, there's only some research on the matter- and fewer companies working on its development, which could be a possible concern.