The presence of antibodies in the nose constitutes a first protection against viruses.
If 78.3% of the participants in the survey, all vaccinated, had antibodies in the nose, differences in proportionality exist for each vaccine. Thus, 96% of people who have received their two doses of Pfizer vaccine have antibodies in the nasal cavities, but this percentage drops to 59% with regard to the AstraZeneca vaccine.
However, these antibodies located in the nose and present in the blood can already block the binding of the virus with human cells. “The coronavirus enters our bodies via the upper airways”, explained Dr. Philippe Gevaert, ENT specialist. “If antibodies are already present in the nose, they can form a first protection against the virus”, he added.
As to why such a vaccine is more effective than another, it is not yet known. “‘The explanation may lie in a different time between the two doses or in a different effect of the vaccines”, hypothesizes the infectious disease specialist Linos Vandekerckhove. “Through a follow-up study, we will map the evolution of the antibody response in the blood and in the nose. We hope to gain more clarity in this way.”