The CDC says about 8% of Americans, which is more than five million people, are skipping their second dose of the coronavirus vaccine.

The first dose of the vaccine provides 80% immunity, but medical experts say you are not fully vaccinated unless you receive both doses of either Pfizer or Moderna.

The CDC says the statistics do not take into account people who may have received their doses at different clinics.

Experts found some people were worried about getting sick from the second shot. And others just couldn't find time to get to that second appointment.

"There's flexibility to receive them up to six weeks after the first dose," said Dr. Guido Macchiavello, from St. Barnabas Hospital. "If you have not been able for whatever circumstance to receive the vaccine on day number 21, we'll talk to your health care provider."

Not receiving your second dose could affect herd immunity.

Doctors say side effects are normal with any vaccine and getting both doses could also protect against variants.