New Delhi, Dec 15 (PTI) Administration of COVID-19 vaccine directly into the respiratory tract, the main gateway for SARS-CoV-2 infection, could lead to greater coverage against the disease, according to a study conducted in monkeys.
The global COVID-19 vaccination campaign saved an estimated 20 million lives, researchers said.
However, while existing COVID-19 vaccines offer coverage against the onset of severe illness, they do little to prevent infection and transmission, they said.
“The failure of the existing generation of intramuscular (IM) SARS-CoV-2 vaccines to block infection is most likely similar to their inability to induce physically powerful mucosal immune responses at the gateway,” said corresponding researcher Dan H. Barouch, Beth Israel. Deaconess Medical Center (BIDMC), United States.
“In this study, we demonstrate that new vaccination methods can particularly develop mucosal immunity in non-human primates and protective efficacy against mucosal viral challenge,” Barouch said.
The study, published in the journal Nature, suggests that it would be possible to improve COVID-19 coverage by administering the vaccine directly into the respiratory tract.
Barouch and colleagues started adult rhesus macaques with the Ad26 COVID-19 vaccine (Janssen/Johnson
A year later, the animals gained a booster. Of the total, 3 teams won a dose of the Ad26 vaccine in the IM, intranasal (IN) (administered by nasal spray) and intratracheal (IT) (nebulizer) directions. or inhaler).
The fourth won one dose of the bivalent mRNA vaccine (Pfizer-BioNTech) IN. A fictitious one didn’t earn callbacks.
When the macaques were faced with a maximum dose of the virus, the researchers took samples of the animals’ blood, nasal fluids and lungs to monitor their immune responses.
They found that the computer-administered Ad26 booster provided near-complete coverage against high-dose SARS-CoV-2 challenge and induced greater mucosal immunity than the IN or MI route.
Conversely, strengthening mRNA IN was found to be ineffective, suggesting that improved formulations are most likely needed for effective mucosal delivery of mRNA vaccines, the researchers said.
“Taken together, these insights demonstrate that new vaccination methods can particularly develop mucosal immunity in non-human primates and protective efficacy against mucosal viral challenge,” Barouch said.
“This knowledge demonstrates the feasibility of developing vaccines that block respiratory viral infections,” he added. PTI SAR KRS SAR
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