Science isn’t a matter of who to believe. That’s just the way the “news” media present it, because most journalists and editors treat everything like politics or crime; they don’t know any better.
Science is a matter of considering evidence, and there’s lots of that which is available to the public, if you know where to look.
Vaccine dangers and safety are a good example. These are checked from public health service records. I’m not saying it’s infallible, but it’s much, much better than secret trials by manufacturers hidden behind NDAs.