By the thousands, U.S. service members are refusing or putting off the Covid-19 vaccine as frustrated commanders scramble to knock down internet rumors and find the "RIGHT PITCH" that will persuade troops to get the shot.

Some Army units are seeing as few as one-third agree to the vaccine. Military leaders searching for answers believe they have identified one potential convincer: an imminent deployment. Navy sailors on ships heading out to sea last week, for example, were choosing to take the shot at rates exceeding 80 percent to 90 percent.

Air Force Maj. Gen. Jeff Taliaferro, vice director of operations for the Joint Staff, told Congress on Wednesday that “very early data” suggests that just up to two-thirds of the service members offered the vaccine have accepted.

“We cannot make it mandatory yet,” Vice Adm. Andrew Lewis, commander of the Navy’s 2nd Fleet, said last week. “I can tell you we’re probably going to make it mandatory as soon as we can, just like we do with the flu vaccine.”

About 40 Marines gathered recently in a California conference room for an information session from medical staff. One officer, who was not authorized to publicly discuss private conversations and spoke on condition of anonymity, said Marines are more comfortable posing questions about the vaccine in smaller groups.

The officer said one Marine, citing a widely circulated and false conspiracy theory, said: “I heard that this thing is actually a tracking device.” The medical staff, said the officer, quickly debunked that theory, and pointed to the Marine’s cellphone, noting that it’s an effective tracker.

Other frequent questions revolved around possible side effects or health concerns, including for pregnant women. Army, Navy and Air Force officials say they hear much the same.