Hackers have gained access to documents related to the Pfizer vaccine against coronavirus, the European Medicine Agency (EMA) reported on Wednesday.

The agency did not give any further details about the cyber attack on the Amsterdam based EMA but vaccine producers Pfizer and BioNTech said in a statement that no personal details of trial participants have been compromised.

The incident will not affect the current approval procedure of the vaccine for the European market, they said.

It is not clear whether documents unrelated to the vaccine were also accessed and an ongoing investigation has as yet not produced any clues to who the perpetrators are.

The Pfizer vaccine is first in line for EU approval. The United Kingdom, which fast-tracked approval, started its vaccination programme earlier in the week.

In the Netherlands vaccination is expected to start in the first week of January when it will take delivery of some 500,000 doses. The Moderna vaccine is also currently awaiting approval from the EMA.