Investigating the presence of antibodies to SARS-CoV-2 in nasal mucous

20 April 2020

Radboud university medical center has launched a study into the presence of antibodies to the coronavirus in nasal mucous. The aim is to show whether antibodies can be found in nasal mucous after a mild infection with few or no symptoms. The study focuses partly on children, because they often have few or no symptoms when infected with the coronavirus. This can provide important insights into herd immunity in the population. The study is complementary to the current coronavirus research at RIVM.
 
Much research is now being conducted into antibodies to the coronavirus. These antibodies are usually detected in the blood. These blood tests determine whether people have been infected with the coronavirus, which can provide insight into herd immunity in the population. High levels of antibodies in the blood are detectable in people who have recovered from a severe coronavirus infection. However, previous research with other respiratory infections has shown that mild infections, or infections without symptoms, can sometimes induce antibodies in the upper respiratory tract but not in the blood. It is unknown whether this also applies to the coronavirus.
 
Radboud university medical center researchers Dimitri Diavatopoulos and Marien de Jonge, both theme Infectious diseases and global health, have therefore started a clinical study into COVID-19 in 50 families: the MuCo study. It focuses primarily on whether antibodies can be measured in nasal mucous after a mild infection or exposure to the virus. In collaboration with Utrecht University, Radboud university medical center researchers are investigating whether these antibodies can inhibit infection with the virus. This is called 'virus neutralization'. The MuCo study focuses in part on families with children, because children often experience few or no symptoms. The first results are expected in several months. 

Fifty hospital workers and their families

The research team, affiliated with the Center for Infectious Diseases of Radboud university medical center, has now visited 50 families at home. The study began with hospital staff from Radboud university medical center, Canisius-Wilhelmina Hospital (both in Nijmegen) and Rijnstate hospital (in Arnhem) who have tested positive for the coronavirus and therefore are, or have been, in home isolation. During the home visit, a sample of nose and throat mucous is taken from all members of the household to determine whether the virus is present. The 50 families are then followed for a month during which the participants themselves take nasal mucous samples at various times by means of an absorbent nasal strip. The also keep a symptom diary to distinguish between mild and more severe symptoms. The samples are then tested with a very sensitive method to determine whether antibodies to the coronavirus are present and whether they can neutralize the virus. 

RIVM and Utrecht University

This study is led by Radboud university medical center, but is coordinated with RIVM and is complementary to other ongoing studies at RIVM. Radboud university medical center is focusing primarily on immunity in the upper respiratory tract. The study involves a collaboration with Frank van Kuppeveld and Berend Jan Bosch of the Faculty of Veterinary Medicine at Utrecht University, which has substantial expertise about coronaviruses and extensive experience in measuring virus neutralization.