Dear Gael
To my knowledge there are several programs in different universities, also there are many fellowships in this matter.
1. Karolinska Institute in Sweden they have " Joint Master Programme in Health Informatics", it is a two years program with stockholm university.
http://ki.se/en/programme/5HI12/16-17 [Applications is Open]
2. Rollins School of Public Health at Emory University, USA, they have "Master of Science in Public Health: Public Health Informatics"
https://www.sph.emory.edu/departments/bios/degree-programs/msph-phi/index.html [Application is Open]
3. Mailman School of Public Health at Culombia University, USA, Master of Public Health "concentration Public Health Informatics"
Application is closed as far as I know
4. CDC has a fellowship called Public Health Informatician Fellowship Program PHIFP, [Application is also closed]
I hope that I satistifed your inquiry, please let me know if you found something else or similar because I am also intrested in same field
All the best,
Ossama