The FDA is expected to approve the very first COVID booster shots.

But the booster shots won't initially be for everyone. A source familiar with the process says the agency is expected to greenlight booster shots for the immunocompromised before the end of the week.

Over 9 million Americans are immunocompromised, and there are concerns over the vaccines’ effectiveness over time. A Johns Hopkins study says that the people with underlying conditions are 485 times more likely to end up in the hospital or die from COVID - even if they are vaccinated.

This includes those who may be under treatment for cancer and be receiving immunocompromising drugs. “It could also include those who are organ transplant recipients and may be on medications that suppress the immune response. So we've been concerned about these individuals. We've been following them closely. And I think most of us believe that we've got to do more to protect these individuals,” says U.S. Surgeon General Dr. Vivek Murthy.

If approved, the boosters would apply to those who got the Pfizer and Moderna vaccines - which are two doses each. More studies need to be done for the Johnson & Johnson vaccine.

Don Wintman, of New City, tells News 12 he received a kidney transplant just over one year ago and that he goes through monthly treatment with medication to suppress his immune system - that way his body does not reject the new kidney. He says he has been fully vaccinated with the Moderna COVID vaccine since February but that he developed little to no antibodies for COVID. Between his immune system and living with his 95-year-old mother, he says concern for COVID runs high in his household. That's why a third dose of the vaccine is something he says he'll strongly consider. "I think for me it's more about potential peace of mind. Like I said, I go out and it’s all unknown out there. If it will give me a little bit more protection against what's out there, then I'm all for it…Some protection is better than no protection," says Wintman.