In my opinion pretending the vaccine is 100% effective and carries 0 risk has done more to shake public confidence than informing people about the risks no matter how small. In the information age it has become easier than ever to find contradicting data and there will always be contradicting data.

Besides, most people have enough life experience to intuitively know that there's no certainty in life. Being honest with people will do more to gain their trust than enhancing the truth for their own well-being.