The international vaccine supply chain has been targeted by cyber-espionage, according to IBM, APA reports citing BBC.
The company says it tracked a campaign aimed at the delivery "cold chain" used to keep vaccines at the right temperature during transportation.
The attackers' identity is unclear - but IBM said the sophistication of their methods indicated a nation state.
It follows warnings from governments - including the UK's - of countries targeting aspects of vaccine research.
IBM says it believes the campaign started in September 2020.
It says phishing emails were sent out across six countries, which targeted organisations linked to the Cold Chain Equipment Optimisation Platform (CCEOP) of Gavi, the international vaccine alliance.
Gavi's partners include the World Health Organization, Unicef, the World Bank and the Bill & Melinda Gates Foundation. They help distribute vaccines around the world to some of the poorest regions.
This sometimes requires a "cold chain".
For example, the Pfizer-BioNTech vaccine - which was not the specific target of this campaign - will need to be kept at a temperature of about -70C as it is moved about.