Sen. Steve Daines revealed on Wednesday that he participated in a blind COVID-19 vaccine study conducted by Pfizer in the fall and tested positive for coronavirus antibodies in October.

In a press call, Daines said he experienced few side effects other than a passing chill, and urged Montanans to consider a COVID vaccination when it's approved for distribution.

“My goal in all of this was to help build confidence and trust in Montanans and the American people who are wondering if they should take the vaccine once it's approved,” Daines said. “To get back to normal and through this pandemic, we'll need a safe and effective vaccine.”

Daines said he received a call from his mother in August telling him that Pfizer was looking for participants to enroll in a COVID-19 vaccine trial in Bozeman. Daines and his wife both joined the study.

Participants were tested for COVID-19 antibodies before the trial began to make sure they hadn't received the virus. Daines tested negative at the time, as he has in past tests when interacting with the president and vice president.

“It was a blind trial,” Daines said. “When they administered the vaccine, about half the participants received a placebo and half received that actual vaccine. The participants weren't told which one they were receiving.”

Daines said he suffered a mild chill after receiving the first shot, but it resolved and he felt fine the next day. He had a similar experience after the second shot.

“I had an antibody test in October and it confirmed I had the COVID antibodies,” Daines said. “While there's no way to know for sure, I believe I received the COVID-19 vaccine.”

Pfizer on Wednesday reported that its two-dose vaccine was over 95% effective. Pfizer will be asking the FDA for emergency use authorization in the coming days.

The company is expected to produce up to 50 million doses this year and 1.3 billion doses by the end of next year. Moderna also has achieved success with its vaccine, meaning the two variations could see distribution begin later this year.

“There's already been a lot of thought into how to prioritize the distribution of the vaccine,” Daines said. “They'll be prioritizing those who are most vulnerable and the front-line healthcare workers. There's a very detailed and well-thought-out prioritization going on as it relates to where the vaccine will be distributed and who will see it first.”

Gov. Steve Bullock on Tuesday tightened regulations across the state in an effort to curb the virus' rampant spread. State health officials reported more than 1,230 new cases of COVID on Wednesday – the fifth highest total since the pandemic began back in March.

More than 561 Montanans have died and coronavirus now represents the fourth leading cause of death in the state.

Daines said an effective vaccine will be needed to return to normalcy and reboot the economy.

“While I believe a vaccine is key to getting back to normal, I don't believe in mandating it,” he said. “But I would encourage Montanans to get the vaccine once it's approved in consultation with their doctors. I trust Montanans will make that decision for themselves and use their own common sense and practice their own personal responsibility.”