WASHINGTON (AP) — More than 12,000 military service members refusing the COVID-19 vaccine are seeking religious exemptions, and so far they are having zero success.

That total lack of approvals is creating new tensions within the military, even as the vast majority of the armed forces have gotten vaccinated.

The services, urgently trying to keep the coronavirus pandemic in check by getting troops vaccinated, are now besieged with exemption requests they are unlikely to approve. Meanwhile, troops claiming religious reasons for avoiding the shots are perplexed because exemptions are theoretically available, yet seem impossible to obtain.

Caught in the middle are chaplains, who must balance the desire to offer compassionate care and guidance to personnel with the need to explain a complicated process that may well be futile. They also must assess requests from those who may be using religion as an excuse to avoid a vaccine that, while credited with preventing needless deaths, has become politically charged.

“So many of them come in thinking that I make the decision, and if they make this case, that it’s a done deal,” said Maj. A’Shellarien Lang, an Army chaplain for the National Guard. “I don’t make the decision. And so when they find that out, it’s a kind of game-changer in the sense that they know that the process has to continue.”