Jahnavi Sarma
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Written By: Jahnavi Sarma | Updated : July 9, 2021 11:28 AM IST
This vaccine targets the mucosal cells, the main entry point and site for early virus replication for most coronaviruses, that line the nasal passages and airways.
Since the beginning of the COVID-19 pandemic, scientists have been working overtime to develop an effective vaccine to protect people against the virus. Major players of the pharmaceutical industry have put their efforts at bringing these shots to the market at the shortest possible time. The result is that, today, we have many vaccines with different levels of efficacy. Countries across the world are using these shots to inoculate their citizens. But one drawback of these vaccines is that it comes with side-effects, both minor as well as major. Recipients complain of aches and pains, fever, fatigue and some have also complained of severe, potentially fatal, allergic reactions. Hence, scientists have continued looking for a safe and effective vaccine. Towards this end, researchers from the University of Iowa and the University of Georgia have assessed the potential of a single-dose, intranasal COVID-19 vaccine. In their studies, they found that this vaccine fully protects mice against lethal COVID-19 infection and also blocks animal-to-animal transmission of the virus. The journal Science Advances published this study.
The experimental vaccine uses a harmless parainfluenza virus 5 (PIV5) to deliver the SARS-CoV-2 spike protein into cells. There it induces an immune response that protects against COVID-19 infection. PIV5 is related to common cold viruses and easily infects different mammals, including humans, without causing significant disease.
It targets the mucosal cells, the main entry point and site for early virus replication for most coronaviruses, that line the nasal passages and airways. This is significant because the virus produced in these cells can penetrate deeper into the lungs and other organs in the body, causing severe disease. Moreover, the virus made in these cells can also be easily exhaled, facilitating faster transmission from one infected person to another.
According to researchers of this study, though the available vaccines against COVID-19 are very successful, the majority of the world's population is still unvaccinated. They also stressed on the fact that there is an urgent need for additional vaccines that are easy to use and effective at stopping disease and transmission. They are hopeful that if this new COVID-19 vaccine proves effective in people, it may help block transmission totally. This will stop the pandemic at its track.
Traditional vaccines are injected into the body. But this vaccine is administered through a nasal spray. The vaccine used in this study only requires a single dose. According to researchers, it can be stored at normal refrigerator temperatures for up to at least three months. It is easier to administer and very good for people who have a fear of needles.
Researchers say that the preclinical data show that this vaccine not only protects against infection, but also significantly reduces the chances of transmission. It produced a localized immune response, involving antibodies and cellular immunity. This provided total protection to mice used in the study from fatal doses of SARS-CoV-2. The vaccine also prevented infection and disease in ferrets and blocked transmission of COVID-19 from infected ferrets to their unprotected and uninfected cage-mates.
(With inputs from Agencies)
