HILLSBOROUGH COUNTY, Fla. — Two major COVID-19 vaccine trials are on hold over potential safety concerns, but local health experts said a pause in a trial is actually encouraging.“Frankly, I’ve been shocked at how smoothly most of the vaccine trials have gone,” said Dr. Charles Lockwood Senior Vice President of USF Health.Johnson & Johnson announced Monday it’s pausing its experimental vaccine because of an unexplained illness in one of its participants.“They’re putting a weak virus that expresses the proteins of the coronavirus. You’d expect more problems from that because you’re going to anticipate a more robust immunological reaction to it,” he explained.Eli Lilly is also putting a hold on its Phase 3 Coronavirus antibody treatment. USF professor Dr. Thomas Unnasch says it’s common for late-stage trials of drugs and vaccines to be paused to examine safety concerns.“To make sure that anything that can happen is basically a random effect and not something that is associated with the vaccine and the bad side effect with the vaccine,” said Dr. Unnasch.According to a new poll from Informa Pharma Intelligence, 35% of Americans don’t trust how quickly the COVID-19 vaccine trials are moving. Doctors said a pause in trials should be reassuring.“It means that they’re really focused on safety. Which is what I would’ve expected and what I do expect, and this is just further confirmation of it.”In a statement today, Eli Lilly emphasized that the hold on its trial of antibody treatment does not affect any of its other ongoing Covid-19 studies.