A couple of major new developments in the race to find a vaccine for the coronavirus.
Tuesday, the U.S. said it won't join a global effort to find and distribute a vaccine because it's led by the World Health Organization.
That announcement came hours after Oxford said it's ready to begin stage 3 testing in the U.S.
It's the third potential vaccine to reach that phase in the U.S. after Moderna and Phizer.
WAAY-31 asked Huntsville's top infectious disease specialist what you can and cannot expect when a vaccine is finally ready.
"There are times where when you give one shot of the vaccine it's not going to be enough to induce that full immune response," said Dr. Ali Hassoun, infectious disease specialist at Huntsville Hospital.
He predicts one dose of the vaccine likely won't be enough and people will need a second shot.
"That's why they initially give one dose and then what we call the booster or a second dose to help push that level of immunity where we can fight the infection or take care of it," he said.
Hassoun warned relying on one dose could be dangerous because it likely won't immunize you from this strain of coronavirus.
"If you get a benefit it might be very short term comparing to taking two, it'll have a longer term effect," he said.
Several vaccines require booster shots. They include the measles, meningitis, HPV and the chickenpox.
While some doctors are worried vaccine myths may keep some people from getting immunized, Hassoun is confident the majority of people will roll up their sleeves if it means staying healthy.