Do you need a COVID-19 booster shot? What you need to know

A small percentage of Americans are eligible right now to get an extra layer of protection against COVID-19 and its variants; the rest of us will have to wait.

People who are moderately to severely immunocompromised and received either the Pfizer or Moderna vaccine can get an additional dose.

The NC Dept. of Health and Human Services said the booster shot is needed in this population in order to mount a good response to the virus as its Delta variant continues to spread rapidly.

Moderately and severely immunocompromised people make up about 3 percent of the U.S. adult population, according to NCDHHS.

The U.S. Food and Drug Administration amended its Emergency Use Authorization for these two vaccines, but has yet to review a booster plan for the Johnson & Johnson one-dose vaccine.

The Centers for Disease Control and Prevention reports the goal is for the general population to start getting booster shots beginning this fall with eligibility beginning eight months after a second dose of one of the mRNA vaccines.

Dr. Alexa Mieses-Malchuck with UNC Health said there is no mixing and matching when it comes to booster shots.

"If your first round of COVID vaccines were Pfizer, then your third or booster shot should also be Pfizer; the same is true for Moderna," she said.

In a statement sent to ABC11, NCDHHS spokesperson Catie Armstrong said in part:

"Although we continue to see highly effective protection against hospitalizations and severe outcomes for people who are fully vaccinated, we are seeing a decrease in vaccine effectiveness against mild to moderate infection-people getting sick but not severely ill and needing hospitalization. To continue to protect against severe illness, hospitalization and death from COVID-19 as we head into the winter, the U.S. Department of Health and Human Services announced that planning is underway to support booster shots for the general population, likely beginning the end of September.

The timing and populations for boosters for other populations will be available pending full review and recommendations by the Food and Drug and Administration (FDA) and the Centers for Disease Control and Prevention (CDC)."