There is a bit of tension as a man stands before fifty health workers with his sleeve rolled up.
"Robert, I'm going to give you your smallpox vaccination today. Do you have any contraindications to the vaccine?" Robert is the guinea pig. He's not getting the smallpox vaccine yet, but just enduring a little pain.
"You're going to feel fifteen small pricks," he's told.
It's all to teach an important lesson.
"This practice time is really valuable for us," says Sheryl Gajewsky of the Texas Department of Health.
About fifty people took part in Friday's class. If smallpox ever surfaces, they will be on the front lines. They will vaccinate us.
"[We will] know how to give these in an emergency situation, [if we] have mass casualties come in," says ETMC Gilmer nurse Carla Harston.
A lot of these folks give shots every day, but this is different. The thought of the pitchfork-shaped needle was a little unnerving.
"I don't take any kind of flu shot or anything, because I don't like needles," says one worker.
Gajewsky says: "It's a very easy vaccination. The prongs are just real tiny, they just barely prick the skin, and that's what they are looking for."
A tiny bit of blood means the vaccine should take. That could mean the difference between immunity and being at risk.
"It is extremely important for everyone to know how to do it, because we haven't done it in twenty five or thirty years," says Gajewsky.