(WWLP) – If you received a Pfizer vaccine shot, you may have received one of these robocalls on Thursday reminding you to sign up for a booster shot.

Remember, the single booster shot can be administered 6 months after receiving the second Pfizer dose, and now marks about 6 months since the general population was eligible for the original vaccine. But not all those people can get the booster yet.

Those currently eligible are: those 65-years and older, and those 18 and up who are at high risk of severe illness. While doctors are encouraging boosters for those eligible, doctors say in Western Massachusetts getting people their first doses is still a main priority.

Dr. Daniel Skiest, an Infectious Diseases Specialist at Baystate Health told 22News, “We have to get everyone vaccinated. Where appropriate, people can have their third dose or booster in some cases especially those over 65 or immunosuppressed. We need to keep our guard up and not let it down.”

Remember, booster shots are only approved for Pfizer’s vaccine. If you received Moderna or Johnson and Johnson’s shot you are not eligible for a booster.

You can schedule an appointment at any major pharmacy like CVS, Walgreens, Stop & Shop, and Big Y.