London, Jan 19 : In a startling revelation, European Medicines Agency (EMA) has said that hackers have manipulated stolen Covid-19 vaccine data in an attempt to "undermine trust" in the vaccines. The ongoing investigation of the cyberattack on EMA found that some of the unlawfully accessed documents related to Covid-19 medicines and vaccines have been leaked on the Internet. "Some of the correspondence has been manipulated by the perpetrators prior to publication in a way which could undermine trust in vaccines," said the latest update from the EMA. The EMA suffered a data breach and disclosed it last month. The leaked Covid-19 data includes internal/confidential email correspondence dating from November, relating to evaluation processes for the vaccines. The news comes at a time when mass vaccination has started in several countries, including in India. "The agency continues to fully support the criminal investigation into the data breach. Necessary action is being taken by the law enforcement authorities," the EMA said in a statement. The UK's National Cyber Security Centre, Microsoft and the World Health Organisation (WHO) have issued warnings over cybercriminals targeting healthcare and pharmaceuticals organisations involved in Covid-19 vaccine development and distribution. Two EU marketing authorisations for Covid-19 vaccines were granted at the end of December/beginning of January following an independent scientific assessment. In December, the EMA said it was hit by a cyber-attack and documents relating to a coronavirus vaccine have been accessed. BioNTech, which makes one of the vaccines in partnership with Pfizer, said its regulatory submission was accessed during the attack. Dr Reddy's which is conducting clinical trials for the Sputnik vaccine had also been the target of a cyber attack. In November, Microsoft detected cyber-attacks from nation-state actors targeting seven prominent companies directly involved in researching vaccines and treatments for Covid-19, including in India. The targets include leading pharmaceutical companies and vaccine researchers in Canada, France, India, South Korea and the US, and came from Strontium, an actor originating from Russia, and two bad actors originating from North Korea called Zinc and Cerium. /IANS