Mucous membranes of the nose and mouth might play a “significant role” in curbing the spread of Covid-19. Scientists have called for more studies to evaluate the role played by this arm of the immune system in asymptomatic and mild states of the coronavirus infection, India Today reported.
The analysis was published in the journal ‘ Frontiers in Immunology’. It noted that the mucosal immune system is the largest component of immunity, but hasn’t been a focus of much of the research on COVID-19 to date.
What are mucous membranes?
Just as skin lines and protects the outside part of the body, mucous membranes line and protect the inside of the body. Mucous membranes can be found inside the nose, mouth, lungs, and many other parts of the body. Mucous membranes make mucus, which keeps them moist
The possible link between mucous membranes and COVID-19?
“We think it is a serious omission to ignore the mucosal immune response to SARS-CoV-2, given its initial sites of infection,” Michael W. Russell, a co-author from the University at Buffalo in the US was quoted as saying.
“Clearly the response of the systemic immunoglobulin G antibody, the most abundant circulating antibody is important, we do not deny that, but on its own it is insufficient,” Russell said further.
He said the initial focus of COVID-19 research was on cases of severe disease when the virus descends into the lower respiratory tract, especially the lungs.
In the lungs, the scientists said the cellular immune responses exacerbate the inflammation rather than fight the infection, the report added.
But since the upper respiratory tract, including the nose, tonsils and adenoids are the initial point of infection for the SARS-CoV-2 virus, they said the immune responses that are triggered there are of special interest.
The researchers believe the high rate of asymptomatic transmission of COVID-19 is another reason why mucosal immunity is so important.
“Given that many infected people remain asymptomatic, and that a large number of those who develop symptoms suffer only mild to moderate disease, this suggests that something, somewhere, does a fairly good job of controlling the virus,” said Russell.
A focus on mucosal immunity might also make it possible to develop a type of vaccine, such as a nasal vaccine, that could be easier to store, transport and administer, the scientists noted.
These vaccines might not have special temperature requirements and might be more palatable for large swaths of the population, especially children because they would not require an injection, Russell was quoted as saying in the report.