Very few (if any) countries will be able to organize a vaccination campaign covering the entire population, with public resources alone. Partnering with private sector actors is the obvious choice to increase speed and scale. While some countries have experience in collaborating with private actors, others are less prepared and are starting from a position of limited mutual understanding, lack of knowledge about capabilities and resources, and lack of trust and experience in writing and executing contracts. This knowledge brief provides practical guidance to address some of these challenges and to reduce the risks of collaboration with an unfamiliar partner.