Three new conditions reported by a small number of people after vaccination with COVID-19 shots from Pfizer and Moderna are being studied to assess if they may be possible side-effects, Europe’s drugs regulator said on Wednesday.

Erythema multiforme, a form of allergic skin reaction; glomerulonephritis, or kidney inflammation; and nephrotic syndrome, a renal disorder characterised by heavy urinary protein losses, are being studied by the safety committee of the European Medicines Agency (EMA), according to the regulator.

The success of the mRNA technology used by the two vaccines has been a turning point for the pandemic and the scientific community, but some rare side-effects are being studied as more people are inoculated globally.

Pfizer, by far the biggest supplier of COVID-19 vaccines to the European Union, and Moderna did not immediately respond to Reuters requests for comment on the new cases.

Just over 43.5 million doses of Moderna’s vaccine, Spikevax, have been administered in the European Economic Area (EEA) as of July 29, the EMA said, compared to more than 330 million doses of the Pfizer shot, Comirnaty, which was developed with Germany’s BioNTech.

Last month, the EMA found a possible link between very rare heart inflammation and the mRNA vaccines. However, the European regulator and the World Health Organization have stressed that benefits from these vaccines outweigh any risks posed by them.

The watchdog did not give details on Wednesday on how many cases of the new conditions were recorded, but said it had requested more data from the companies to study any potential relation between them.

The EMA did not make any recommendations to change the labelling of the vaccines.

It disclosed the new assessments as part of routine updates to the safety section of all authorised vaccines’ database, and added menstrual disorders as another condition it was studying for all vaccines, including those from AstraZeneca and J&J, after the EMA’s update last week.