The ace vaccines against covid-19, which protect the majority of the population from serious illnesses, “they will not be enough to stop the spread of the virus and its variants”according to a new study from the University of Virginia (United States).
“Our data suggests that an intranasal vaccine booster strategy will be essential to protect people from emerging variants of concern,” says Jie Sun, responsible for the work, which was published in the scientific journal “Science Immunology.”
The research of Sun and his colleagues fully documents poor immune response performance in the airways of first-time vaccinees against covid-19 compared to those with a natural infection.
The main vaccines are mRNA because they are inspired by messenger ribonucleic acid, the transmission system that facilitates biological replication. But the mRNA for vaccines does not come from a live virus.
In its place, the molecule is synthesized in the laboratory to make it look like an invader, enough for the body to recognize the real thing in the future. However, with these vaccines, “the message” seems largely confined to the blood.
According to the study, the blood is strongly stimulated by the vaccine, while the mucous membranes to experience a response moderate neutralizing antibodies or limit.
“The omicron variant almost completely escaped neutralization by mucosal antibodies in people who have received mRNA vaccines and in people previously infected. Our data showed that mRNA vaccination also did not induce sufficient cell-mediated immunity reside in the tissues of the respiratory tract, another arm of our immune system to prevent the virus from entering our body,” explains Sun.
The researchers found that only the bodies of seriously ill unvaccinated patients fought vigorously against the virus in his airways and blood circulation, a less than ideal way to achieve a united front.
However, separate component of new research raises hope that vaccines will soon provide full coverage.
The bone mouse who have received a nasal vaccine against adenovirus, a relative of the cold virus family that expresses the spike protein found in covid-19, demonstrated “robust neutralizing antibody responses” in combination with injections of mRNA vaccines.
“Nasal vaccine provides mucosal antigenic boost to the preexisting memory of T and B cells that drive the immune response, leading to increased cellular and humoral immunity,” says Sun.
The increase was found not only in the bronchi of the lungs, but also as an improvement compared to the normal response to the vaccine in the blood. And the response was “effective both against the ancestral virus and against the omicronic variant”, he explains.
Research further confirms scientists’ suspicions that greater immunity to the coronavirus can be built from where the virus first takes root, the mucous membranes of the nose, perhaps stopping it cold.