At least three Seacoast pharmacy chains had the newly US CDC-approved third dose of the COVID-19 vaccine for those with compromised immune systems available on Saturday.

CDC officials gave their okay for the additional dose of the Moderna and Pfizer COVID-19 vaccines late Thursday after reviewing data that shows some people with moderately to severely compromised immune systems do not always build the same level of immunity compared to people who are not immunocompromised.

CVS and Walgreens announced the third dose availability on their respective websites on Saturday morning. CVS is administering the doses by appointment made on its website while Walgreens is offering the shot for walk-in only. Customers will need to provide proof of receiving the first two doses.

Rite Aid in a statement told Seacoast Current it is also administering the third dose on a walk-in basis and is working on making appointments available online.

The third dose may be administered at least 28 days after the initial two doses.

According to the CDC, those who are eligible include individuals who have:

  • Been receiving active cancer treatment for tumors or cancers of the blood
  • Received an organ transplant and are taking medicine to suppress the immune system
  • Received a stem cell transplant within the last 2 years or are taking medicine to suppress the immune system
  • Moderate or severe primary immunodeficiency (such as DiGeorge syndrome, Wiskott-Aldrich syndrome)
  • Advanced or untreated HIV infection
  • Active treatment with high-dose corticosteroids or other drugs that may suppress your immune response

"At a time when the Delta variant is surging, an additional vaccine dose for some people with weakened immune systems could help prevent serious and possibly life-threatening COVID-19 cases within this population," CDC Director Rochelle P. Walensky said in a statement.

Gov. Chris Sununu and his health team at a coronavirus briefing on Thursday said the best defense against another surge in COVID-19 cases caused by the Delta variant is to take the vaccine.

"The vaccine is the way out. You gotta get the vaccine," Sununu said.

State Epidemiologist Benjamin Chan said the vaccine is over 90 percent effective in preventing severe symptoms which can lead to hospitalization or death.

As of Thursday, nearly 54% of New Hampshire residents are fully vaccinated against COVID-19 with almost 59% haven taken at least one dose, according to the state dashboard.

Note: This story was updated to add the availability of the third COVID-19 vaccine dose at Rite Aid locations.

Contact reporter Dan Alexander at Dan.Alexander@townsquaremedia.com or via Twitter @DanAlexanderNH

LOOK: Answers to 30 common COVID-19 vaccine questions

While much is still unknown about the coronavirus and the future, what is known is that the currently available vaccines have gone through all three trial phases and are safe and effective. It will be necessary for as many Americans as possible to be vaccinated in order to finally return to some level of pre-pandemic normalcy, and hopefully these 30 answers provided here will help readers get vaccinated as soon they are able.