(WTEN) – As news of additional doses and booster shots for the COVID-19 vaccine surface, many are wondering what is the difference?

Third shot vs. boosters

At this point, it’s mainly a difference in eligibility and timing. Third doses are recommended by the Centers for Disease Control for moderately to severely immunocompromised people four weeks after receiving their second Moderna or Pfizer vaccine. That’s because immunocompromised people sometimes don’t build enough of a protective response after the first two doses, and a third dose can help with that.

Booster shots, on the other hand, are going to be recommended for everyone starting in the fall, eight months after your second dose. In the case of booster shots, it’s not because people haven’t built strong enough immunity following the first two doses. Rather, it’s because that immunity might wane over time.

Will the booster shot be the same as the first two doses?

As for the content and makeup of the booster shots, we don’t know yet if people will get the exact same type of shot they received the first time around or if it will differ slightly, reports the Associated Press.

Who will be prioritized for boosters first?

Right now, those who are immunocompromised or have other health issues are first in line for a third shot. The priority for booster doses, according to the CDC, will be given to those who were first given COVID-19 shots because they are most at risk. That includes health care workers, nursing home residents, and seniors.

What about people who received the J&J vaccine? Will they get a booster shot?

The CDC said it’s likely those who received a Johnson & Johnson vaccine will need a booster shot, but the agency hasn’t formulated a plan for them yet. The CDC said it is still collecting data and plans to announce a plan in the coming weeks.