Nasal vaccines promise to stop the COVID-19 virus before it gets to the lungs – an immunologist explains how they work
- December 23, 2022
- Posted by: OptimizeIAS Team
- Category: DPN Topics
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Nasal vaccines promise to stop the COVID-19 virus before it gets to the lungs – an immunologist explains how they work
Subject : Science and Technology
Context:
- Researchers are in the process of developing alternative approaches to vaccines to improve their effectiveness, including how they’re administered. Immunologists at the University of Buffalo explain how nasal vaccines work.
How does the immune system fight pathogens?
- The immune system has two distinct components: mucosal and circulatory.
- The mucosal immune system provides protection at the mucosal surfaces of the body. These include the mouth, eyes, middle ear, mammary and other glands, and the gastrointestinal, respiratory and urogenital tracts.
- The circulatory part of the immune system generates antibodies and immune cells that are delivered through the bloodstream to the internal tissues and organs.
- The mucosal and circulatory compartments of the immune system are largely separate and independent.
What are the key players in mucosal immunity?
- The immune system generates antibodies (Immunoglobulins) in response to invading agents that the body identifies as “non-self,” such as viruses and bacteria.
- The mucosal immune system generates a specialized form of antibody called secretory IgA, or SIgA.
- Other key players include: different types of anti-microbial proteins that kill pathogens and immune cells that generate antibody responses.
How does the COVID-19 virus enter the body?
- The virus that causes COVID-19, SARS-CoV-2, enters the body via droplets or aerosols that get into one’s nose, mouth or eyes.
- It can cause severe disease if it descends deep into the lungs and causes an overactive, inflammatory immune response.
How do nasal vaccines work?
- Vaccines can be given through mucosal routes via the mouth or nose.
- This induces an immune response through areas that stimulate the mucosal immune system, leading mucosal secretions to produce SIgA antibodies.
- There are several existing mucosal vaccines, most of them taken by mouth.
- Currently, only one, the flu vaccine, is delivered nasally.
- If the SIgA antibodies in the nose, mouth or throat target SARS-CoV-2, they could neutralize the virus before it can drop down into the lungs and establish an infection.
Advantages:
- It will block the virus at the entry point itself.
- Secretions with a sufficiently high level of SIgA antibodies against the virus could neutralize and thereby diminish its transmissibility.
- Existing vaccines do not induce SIgA antibody responses.
- Nasal vaccines may be a useful supplement to injected vaccines in hot spots of infection.
- Since they don’t require needles, they might also help overcome vaccine hesitancy due to fear of injections.