I’m talking about viral vector as a delivery method. And you’re talking about testing a COVID-19 vaccine, right? Of course there’s none. But there’s no way to do a long-term testing of a particular COVID-19 vaccine. By the time you finish the study it’s going to be too late. So if someone says “But a vaccine hasn’t been studied long enough!” they just propose to not vaccinate at all and rely on lockdowns/post-illness immunity. However, we’ve got sufficient knowledge about the mechanism of the used vaccines to say they’re sufficiently safe.