Ghent, September 15, 2021 – Researchers from UZ Gent and VIB (Flemish Institute for Biotechnology) have studied the production of COVID-19 antibodies in the nose. 78.3% of the study participants built up antibodies at that site after their vaccination. Those antibodies in the nose can be a major brake on infection and spread.

Antibodies as protection against COVID-19

“The coronavirus enters our body through the upper respiratory tract,” explains nose, throat and ear specialist Prof. Dr. Philippe Gevaert. “Neutralizing antibodies in our blood render the virus harmless by blocking the binding of the spike proteins to human cells. If the antibodies are also present in the nose, they can already form a first barrier there against the entry of the virus. It is therefore important to also investigate the reaction to an infection and vaccination in the nose.’

Most antibodies in nose after Pfizer vaccination

The blood and nose were examined twice in 46 study participants: just before the first vaccination with Pfizer or AstraZeneca and 13 to 40 days after the second vaccination. 23 participants had an infection before their vaccination. Just before their first vaccination, only 17.4% of them showed antibodies in the nose. After full vaccination, 78.3% of all participants built up antibodies in the nose.

The participants who received Pfizer showed more antibodies (96%) than the participants who received AstraZeneca (59%). Also, the local antibodies in Pfizer showed a stronger neutralization of the viral spike protein than in AstraZeneca. A past COVID-19 infection had no influence on the results. The blood analysis showed the same amount of antibodies in both vaccination groups.

Continuation of the study

It is not yet clear why some vaccines generate antibodies in the nose more often than others. “The explanation may be due to a different time span between the two doses or to a different effect of the vaccines,” suspects infectious disease specialist Prof. Dr. Linos Vandekerckhove. “During a follow-up study, we will map the further evolution of the antibody response in the blood and in the nose. We hope to gain more clarity in this way.”