So a vaccine that failed the test stops being a vaccine? That is news for me. Also we do not live in a static world - yesteryear's vaccine might be ineffective to today's viruses. Also what about vaccines that have been approved in some countries and rejected in others?
Also this does not distinguish between the "no-brainer" vaccines where the benefits clearly outweigh the risks and costs and the vaccines that are just barely beneficial.
So basically the question is completely wrong and should instead be: "Do you believe that the testing procedures of vaccines are safe and effective."
In that case I would also say that this is doubtful.