The article specifically states "we are unaware that any study participants have been identified through the data being accessed".
The breached data concerns "confidential information about the vaccine and its mechanism of action, its efficiency, its risks & known possible side effects and any unique aspects such as handling guidelines". What strikes me is the fact that this information is confidential at all.
I know, this was exactly of my point: I felt that OP didn't read the article, and it didn't occur to them that "vaccine data" could also refer to personal information in their blanket dismissal. In this concrete case it wasn't the case, but that all "vaccine data" should be open is certainly privacy nonsense. Once you introduce that definition I agree.
The breached data concerns "confidential information about the vaccine and its mechanism of action, its efficiency, its risks & known possible side effects and any unique aspects such as handling guidelines". What strikes me is the fact that this information is confidential at all.