The Dutch laboratory which investigates the side effects of medicines says there is not enough evidence of a link between coronavirus vaccines and symptoms that are similar to Long Covid and is recommending further research.

By last August, the lab had received 2,282 reports of long-lasting side effects in people who were vaccinated against coronavirus, of which 78 involved symptoms which are “like those of Long Covid”.

“Like Long Covid, these were very diverse” and included breathlessness, tiredness, chest pains, dizziness, muscle ache and brain fog, Lareb said in a new report, published on Wednesday.

In total 41 of the 78 patients underwent medical checks and 16 people self-diagnosed their complaints. Eleven people were diagnosed as having Long Covid and three chronic fatigue syndrome.

However, the lack of medical research on a large number of the patients means it is impossible to say if their symptoms could have other causes, such as an actual coronavirus diagnosis, Lareb said. In addition, 39 of the patients had previously had coronavirus.

“A causal relationship with Covid-19 vaccination cannot be established since potential alternative causes could not be excluded,” Lareb said. “Further epidemiological, clinical and immunological research is needed.”

Meanwhile, the health ministry said on Wednesday that just 425 care workers with Long Covid have been awarded €15,000 in extra financial support, even though 806 had registered for the cash.

In total, 340 claims were rejected because they were made by people who did not fit the criteria, 37 claims were made too late, and 40 are still being considered, health minister Conny Helder told MPs in an update. The government had expected around 1,000 claims.

Healthcare workers accounted for a high proportion of infections in the first wave of coronavirus in the spring of 2020, when they were denied proper PPE and exempted from many of the quarantine restrictions so they could keep working.