The second COVID-19 booster shot is available for those who are 50 or older or have underlying health problems, but many are left wondering if they should get it. Dr. Shad Marvasti with the University of Arizona’s College of Medicine suggests some people should definitely get the booster.  

“We know for sure that people who have had a transplant or are otherwise on medication that basically suppress their immune system, those folks definitely need it because they don’t elicit that much of an immune response, even after one, two, or even three shots," Marvasti said. 

While stressing the importance of a universal first booster, he says there may come a point when everyone should get the fourth shot.

"You definitely should get it, no matter who you are, if we are seeing another surge from a new variant," Marvasti said.

According to the Arizona Department of Health Services, over 70% of state residents are vaccinated with at least one dose.