Filenews 2 August 2021
A vaccine against coronavirus, given with drops from the nose, is now being developed by scientists in an effort to find an easier way to dispose of pandemic vaccines.
Experiments on Syrian "golden" hamsters conducted at St. Louis University involved a vaccine with chimpanzee adenovirus and stabilized protein – spike S, which was administered to 21 mice aged 5-6 weeks, either through the nose or intramuscularly, by injection. These hamsters were selected because coronavaid disease simulates disease in humans and that is why they are the test animals of choice in the covid –19 study.
The results showed that hamsters who took the vaccine intranasally developed six times more antibodies against the virus than those who received the vaccine intramuscularly.
As the researchers note in a publication in the scientific journal Cell, the results of administration of the vaccine through the nose, succeeded in preventing pneumonia, reduced viral load, gene expression of inflammation, pathogenicity of the lungs, etc.
How the study was done
Describing their study, the experts noted that they studied hydroxychloroquine, which had no effect on the virus or the antibody titles of mice, favipiravir reduced the viral load only when used in high doses, followed by vaccine tests, with "vehicles" the yellow fever virus 17D, adenovirus, Newcastle virus, cystic somatoitis virus, etc.
This study included the administration of a single-dose vaccine, with 1010 virus particles and as a "vehicle" for administering the chimpanzee adenovirus. It was found that intranasal administration caused the development of antibodies, six times more than intramuscular administration.
In addition, after administration of the vaccine, the immune animals had less infectious virus and RNA of the virus in the lungs and nose, which led to fewer symptoms and milder disease three days after infection, showing that administration of the vaccine intranasally provides greater protection against SARS-CoV-2.
The finding came with plasma from mice, before infection with the virus through the vaccine and 21 days later.
In addition to developing neutralizing antibodies, the researchers found that with intranasal administration, mice had 100 times fewer copies of the N gene than intramuscular administration, and no cells positive for the virus were detected after immunisation by administering the vaccine through the nose.
As regards protection against the disease and prevention of transmission, intranasal administration showed greater protection in the upper respiratory system against intramuscular administration of the vaccine.
