News highlight:
Bharat Biotech’s intranasal Covid vaccine has been approved by the Union Health Ministry as a booster dose for those above 18 years of age.
Key takeaway:
- The needle-free vaccine will be available at private centres. It will be introduced on the Co-WIN platform soon
- It is likely to be rolled out in the national Covid vaccination programme soon.
iNCOVACC (BBV154):
- About:
- It is a first covide vaccine which will be delivered through the nasal route.
- Developed by: Bharat Biotech International Limited
- It can be administered only to the unimmunised.
- The vaccine uses a modified chimpanzee adenovirus, which cannot replicate in the body, to carry the Covid spike protein to induce immunity.
- Currently, Covishield, Covaxin and Corbevax are part of the Government’s Covid immunisation drive while vaccines like Covovax and Sputnik are available at private centres.
- Features:
- It protects against infection and reduce transmission of the virus.
- No need for needles and syringes.
- Reduce dependence on trained personnel to administer the shots.
- Stable at 2-8°C makes it easy to store and distribute.
- Developed Under:
- This vaccine was developed under the mission COVID Suraksha, which was launched to reinforce and accelerate COVID-19 vaccine development efforts as part of the third stimulus package, Atmanirbhar 3.0.
- The focus of this mission is to consolidate and streamline available resources toward a warpath for accelerated vaccine development in order to bring a safe, efficacious, affordable, and accessible COVID-19 Vaccine to the citizens at the earliest with a focus on Atmanirbhar Bharat.
Nasal vaccine:
- Administration methods:
- Vaccines are generally administered in a variety of ways, with the most popular being intramuscular injections into the muscles or the tissue immediately next to the muscles (subcutaneous).
- There are alternative administration methods as well, like for infants, giving the liquid solution orally rather than intravenously for some vaccines.
- For intranasal administration, the vaccine is sprayed into the nostrils and inhaled nasally.
- An intranasal vaccine stimulates a broad immune response thus, neutralizing IgG, mucosal IgA, and T-cell responses.
- Immune responses at the site of infection (in the nasal mucosa) are essential for blocking both infection and transmission of COVID-19.
- Immune response:
- Numerous viruses, including the coronavirus, enter the body through the mucosa, the moist, spongy tissues that border the nose, mouth, lungs, and digestive system. This causes these cells and molecules to mount a special immune response.
- According to experts, an intranasal vaccine can fight against the virus even before it tries to cross the body’s protective barrier.
- Since intramuscular vaccinations rely on immune cells that have been mobilized from elsewhere in the body to swarm to the site of infection, they typically fail to trigger this mucosal response.
- Working:
- Vaccines generally invoke an immune response in the body through the B cells and T cells which produce immunoglobulins or antibodies like IgG to fight the disease-causing foreign bodies.
- The T cells help the B cells by memorizing the foreign bodies for future response.
- Nasal vaccines will activate the B cells residing near the mucosal lining tissues.
- These B cells will produce IgA antibodies which specialize in destroying airway pathogens.
- The T cells in the area will memorize the pathogens for future response.
- Types of mucosal vaccines:
- Unit dose liquid: Single dose nasal spray system
- Bidose liquid: Bidose nasal spray system
- The multi-dose liquid device system
- Unit dose powder: Active, single dose nasal powder delivery system
- Bidose powder: Passive, Bidose nasal powder delivery system
Concerns:
- There is very little evidence to back the effectiveness of this route of delivery so far and, except for some flu vaccines, attempts to deliver vaccines like this have not been successful.
- Though they are primarily safe, their efficacy is tough to achieve as it depends on multiple bioengineering approaches.
- It still lacks sufficient data on human trials hence mass administration may provide false outcomes.
- Single dose devices will give the best protection for the vaccine, but require highly sophisticated filling technology.
Pic Courtesy: The Hindu
Content Source: The Hindu