New Delhi: A nasal vaccine adjuvant, or a substance added to nasal vaccines to trigger a stronger immune response, was found to stop COVID-19 infection in both young and old mice. Several current vaccines contain adjuvants, which boost the effectiveness of a vaccine. While vaccines are known to offer protection against serious illness and death, vaccines can be improved in their ability to stop the spread of SARS-CoV-2 at the point of entry in the upper respiratory tract, the research led by the University of Michigan (U-M) and the Icahn School of Medicine at Mount Sinai, US, said.
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Their vaccine protocol combines a nanoemulsion, similar to a tiny droplet of oil and water, and an RNA-based molecule, which is the adjuvant, recognised by the immune system.
The RNA adjuvant triggers antiviral pathways inside the cell while the nanoemulsion carries it into the cell, the study published in the journal NPJ Vaccines said.
This helps prevent the adjuvant from being cleared too quickly from inside the nasal passages, along with activating immune pathways complementary to the one triggered by the RNA adjuvant, it said.
Testing the combined vaccine, including the adjuvant, the researchers detected an enhanced antibody and memory T cell response in both young and old mice, including in the mucus-secreting membrane lining of the upper airway where the virus starts to proliferate. Michael Schotsaert, co-corresponding author of the study and an assistant professor of microbiology at Icahn Mount Sinai, said,
It’s very hard to induce a strong immune response with intranasal vaccines containing just the protein or inactivated virus alone because your mucosal sites will see many things during the day or over a lifetime and are to some extent ‘trained’ not to overreact. So, you want to overcome that barrier through the use of adjuvants while balancing safety.
Further, the nanoemulsion can inactivate viruses on its own, the researchers said. Pamela Wong, a research assistant professor in the U-M Medical School, said,
This means you could mix live virus with the nanoemulsion and it would inactivate it without having to use harsher chemical methods, better preserving the conformation of the viral proteins that the immune system sees, potentially leading to better quality immune responses.
The team plans to pursue further studies for bringing the adjuvant to Phase 1 safety trials, along with exploring its applications for a universal flu vaccine.
There is considerable interest in intranasal vaccines for respiratory viruses because inducing mucosal immunity can help prevent viral transmission, whereas injectable vaccines don’t effectively elicit mucosal immune responses, said Ms Wong.
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(This story has not been edited by NDTV staff and is published from a syndicated feed.)
NDTV – Dettol have been working towards a clean and healthy India since 2014 via the Banega Swachh India initiative, which is helmed by Campaign Ambassador Amitabh Bachchan. The campaign aims to highlight the inter-dependency of humans and the environment, and of humans on one another with the focus on One Health, One Planet, One Future – Leaving No One Behind. It stresses on the need to take care of, and consider, everyone’s health in India – especially vulnerable communities – theLGBTQ population,indigenous people, India’s different tribes, ethnic and linguistic minorities, people with disabilities, migrants, geographically remote populations, gender and sexual minorities. In wake of the currentCOVID-19 pandemic, the need for WASH (Water,SanitationandHygiene) is reaffirmed as handwashing is one of the ways to prevent Coronavirus infection and other diseases. The campaign will continue to raise awareness on the same along with focussing on the importance of nutrition and healthcare for women and children, fightmalnutrition, mental wellbeing, self care, science and health,adolescent health & gender awareness. Along with the health of people, the campaign has realised the need to also take care of the health of the eco-system. Our environment is fragile due to human activity, which is not only over-exploiting available resources, but also generating immense pollution as a result of using and extracting those resources. The imbalance has also led to immense biodiversity loss that has caused one of the biggest threats to human survival – climate change. It has now been described as a “code red for humanity.” The campaign will continue to cover issues likeair pollution,waste management,plastic ban,manual scavengingand sanitation workers andmenstrual hygiene. Banega Swasth India will also be taking forward the dream of Swasth Bharat, the campaign feels that only a Swachh or clean India wheretoiletsare used andopen defecation free (ODF)status achieved as part of the Swachh Bharat Abhiyan launched byPrime Minister Narendra Modiin 2014, can eradicate diseases like diahorrea and the country can become a Swasth or healthy India.
