The oral COVID-19 vaccine not only protects against the disease, but also reduces the airborne spread of the SARS-CoV-2 virus in other close contacts, according to an animal study.
The study, published in the journal Science Translational Medicine, demonstrated the potential of the vaccine to act through mucosal tissue to neutralize SARS-CoV-2, limiting infections and the spread of active viruses in airborne particles.
“Given that most of the world is under-immunized – and this is especially true for children – the possibility of a vaccinated person with a breakthrough infection can spread COVID to non-immunized family or community members poses a risk to public health.” said Stephanie N. Langel of Duke University Medical Center in the United States.
“There will be significant benefits in developing vaccines that not only protect against disease but also reduce the transmission of unvaccinated people,” Langel said in a statement.
Researchers – including teams from the American vaccine developer, Vaxart, and the nonprofit clinical research organization, the Lovelace Biomedical Research Institute – tested a vaccine that uses adenovirus as a vector to express the virus’s thorny protein.
Thorn protein is used by SARS-CoV-2 to enter and infect human cells.
The human vaccine is intended to be taken as a pill, they said.
In studies using hamsters, the vaccine caused a strong response to antibodies in the blood and lungs.
When the animals were exposed to high levels of the SARS-CoV-2 virus, which caused breakthrough infections, they were less symptomatic than unvaccinated hamsters and had lower levels of infectious virus in the nose and lungs.
That’s why they don’t shed as much virus through normal air exposures, the researchers said.
Unlike vaccines that are injected into a muscle, they said, mucosal immunizations increase the production of immunoglobulin A (IgA) – the first line of defense of the immune system against pathogens – in the nose and lungs.
These mucosal entry ports are then protected, making vaccinated less likely to transmit the infectious virus during sneezing or coughing, the researchers said.
“Our data show that mucosal immunization is a viable strategy to reduce the spread of COVID by airborne transmission,” Langel said.
The researchers noted that the study focused on the original SARS-CoV-2 virus and that new studies would be created to test the vaccine against Omicron variants.
(This story was not edited by Devdiscourse staff and is automatically generated by a syndicated channel.)
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