More than 95% of the 1,741 participants in RIVM’s LongCOVID study, who reported long-term symptoms after COVID-19, had mild symptoms during the acute phase of the infection. This is evident from the initial results of the RIVM LongCOVID study. Only 5% of the people participating in the study who reported long-term symptoms were admitted to hospital due to COVID-19. 

The symptoms reported most frequently among the participants were tiredness (90%), concentration problems (74%) and shortness of breath (70%). The average duration of these symptoms among the participants was 7 months at the time they signed up for the study. It is not yet known whether the delta variant causes different long-term symptoms, and whether children have the same long-term symptoms as adults. For that reason, RIVM is asking people in the Netherlands who recently had a COVID-19 test (less than 7 days ago) to sign up for the study via

Impact of coronavirus infection still significant months later 

Almost 90% of the people with long-term symptoms who were surveyed in the LongCOVID study said that the impact of the long-term symptoms was significant or very significant. About 34% of participants stated when they filled in the questionnaire that they were currently no longer able to work due to their long-term symptoms following COVID-19. Moreover, 46% of the participants reported that they were not able to work as much as they did previously as a result of the long-term symptoms.

LongCOVID study for adults and children

The LongCOVID study started in May 2021. Almost 2,800 people are already participating in the study. More than 1,740 participants already had long-term symptoms when they signed up for the study. It is still unclear to what extent these participants are representative of all people who have these long-term symptoms. In order to investigate this properly, people need to be monitored from the start of their coronavirus infection. Few of the current participants are likely to have been infected with the Delta variant. For that reason, RIVM is asking adults and children in the Netherlands who test positive for COVID-19 to sign up for the study via within 7 days after their positive test result. People without a (recent) positive test result and people who have been vaccinated, with or without a (recent) positive COVID-19 test, can also participate  in the RIVM LongCOVID study.

Over the course of an extended time period, the study aims to research how many people continue to have long-term health problems after an infection with the coronavirus SARS-CoV-2. The researchers will also investigate what those health problems are and how long the symptoms persist. They will also look at whether vaccination offers protection against Long COVID, and if so, to what extent. The data can be used to determine the long-term health impact of a coronavirus infection. 

Study by the behavioural research unit 

The potential for lingering negative effects after COVID-19 was also confirmed by the results from the 13th round of the survey study conducted by RIVM’s behavioural research unit. A third (37%) of the participants who had been infected more than three months ago (confirmed by a positive COVID-19 test) reported that they still had symptoms more than three months after infection. These long-term symptoms were most common among people aged 40-69 (39% to 41%). Also, more than a quarter (27%) of the young people surveyed (aged 16-24 years) who had COVID-19 still reported