The nose is the head of the respiratory system.
IgA antibodies in the nasal fluid are the body’s first line of defense against the new coronavirus.
The study included 446 patients with New Crown pneumonia who were hospitalized from February 2020 to March 2021 (the vaccine was not yet available on a large scale and there was no Omicron epidemic yet).
Researchers collected nasal fluid and blood samples from patients at three time points: hospitalization, six months and one year after discharge, during which most received the New Crown vaccine.
The researchers tested the ability of antibodies to neutralize the original strain of New Coronavirus, Delta and Omicron in the samples at different time periods.
The results showed that the antibodies in the blood persisted for at least one year after infection with the new coronavirus.
while antibodies in the nose lasted only nine months and were resistant to the Omicron variant for a shorter period.
Both blood and nasal antibody levels increased after vaccination.
However, the increase in nasal antibodies was smaller and shorter in duration.
The investigators suggest that the results should be extrapolated with caution, as the study population only included the UK inpatient population.
However, they suggest that the use of nasal spray or inhalation vaccines may be more effective in preventing infection and transmission of NIV in the development of the next generation of NIC vaccines.