Nearly twice as often long-term complaints after a corona infection
Three months after infection with the coronavirus, almost half of the people still report one or more long-term complaints, such as fatigue, concentration problems and loss of smell. This is almost twice as often as in people who have not been infected and more than one and a half times more often than in people with other respiratory infections. This is evident from the interim results of the LongCOVID study by the RIVM. Fully vaccinated participants under the age of 2 reported fewer complaints with smell and taste after three months, but for the other long-term complaints no difference was found between people who were not, partially or fully vaccinated at the time of infection.
These results emerge from a questionnaire survey between May and December 2021 among a total of 14572 participants. Among them were 9166 who registered for the study shortly after a positive test. As a control group, 5406 people who had not had corona participated. They registered themselves after a negative test or were invited by letter from the general population.
After three months, complaints such as fatigue (31%), shortness of breath (16%), loss of smell (12%), concentration problems (15%), and problems in a busy environment (13%) were significantly more common in people who had had a corona infection compared to people who had not had corona. In many cases, the fatigue (28%) and/or cognitive problems (15%) and shortness of breath (13%) are so severe that normal daily functioning is severely disrupted.
Effect of vaccination
The effectiveness of the various corona vaccines against hospital and ICU admissions has been demonstrated worldwide. Whether and to what extent vaccination also protects against long-term complaints if you still get an infection after vaccination is even less clear. In participants under the age of 65, this study was able to investigate whether there was a protective effect of vaccination prior to infection with the coronavirus. Participants under the age of 65 who were fully vaccinated reported less problems with smell and taste after 3 months than people who were not vaccinated. No difference was found in how often the other long-term complaints occur between people who were not, partially and fully vaccinated at the time of infection. International studies into the effectiveness of vaccination against long-term complaints show varying results. Further research is therefore needed to be able to make substantiated statements about this.
This study not only shows that a large proportion of COVID-19 patients continue to have long-term complaints after recovery from the acute disease, but also that these complaints occur much more frequently in these patients than in people with other respiratory infections and people from the general population. The fact that the complaints also occur regularly in people who have not had corona illustrates the challenge for healthcare providers in clinical practice to determine for a patient to what extent a complaint is caused by Long COVID, also called post-COVID, or by another cause.
This round of research mainly involved infections with the alpha and delta variants of the coronavirus. Whether the results found also apply after infection with the omikron variant will become clear in the next interim results of the Long COVID study.
