There are certainly situations where specific vaccine formations have caused measureable harm. For example in Japan there was a specific formulation of MMR vac

There are certainly situations where specific vaccine formations have caused measureable harm. For example in Japan there was a specific formulation of MMR vaccine that led to high rates of sepsis. Experts certainly were involved in the messaging around the changes that Japan applied to resolve this issue (the results also helped provide evidence that vaccines don't cause autism). Public messaging around human health, especially with respect to powerful tools that modify the immune system, has always been extremely challenging. Public health officials typically want to maximize health for a whole population, and we know that messaging can lead to society-level changes in behavior around vaccination. So experts are typically quite careful when they talk about harms from vaccines.