• COVID-19 vaccine boosters will become available this fall in the U.S. to people who received the Pfizer or Moderna vaccines.
• People who received the vaccine earliest will be the first eligible to receive boosters, beginning eight months after the date of their second dose.
• People who are immunocompromised — including people taking certain disease-modifying therapies (DMTs) for multiple sclerosis (MS) — may be eligible to receive a third dose of the vaccines now.

On Aug. 18, the U.S. Department of Health and Human Services announced a plan for COVID-19 vaccine booster shots. According to the Centers for Disease Control and Prevention (CDC), vaccine boosters will become available in the U.S. this fall. Details about vaccine boosters are yet to come, and they will be subject to review by the U.S. Food and Drug Administration (FDA) and recommendations by the CDC’s Advisory Committee on Immunization Practices. These organizations are currently examining data on vaccine effectiveness against new coronavirus variants.

Who Will Be Eligible for Vaccine Boosters?

Thus far, vaccine boosters are only recommended for those who received either messenger RNA (mRNA) vaccine, whether from Pfizer or Moderna. (The Johnson & Johnson vaccine works differently, and the need for a booster is being evaluated separately.) The CDC stated that people will become eligible for a vaccine booster eight months after they received their second dose. Those who received the vaccine earliest will be the first to be offered vaccine boosters. In most cases, those with earliest access to the vaccine were older adults, health care providers, and residents of long-term care facilities.

Boosters vs. Additional Doses for Immunocompromised People

A COVID-19 vaccine booster is administered after someone developed adequate immunity after a second dose, but that immunity has decreased over time.

However, an additional dose of the vaccine may be recommended for those who did not develop an adequate immune response after the two-dose vaccination series. The CDC recommends a third dose of the vaccines for moderately to severely immunocompromised people at least 28 days after the second vaccination with the Pfizer or Moderna vaccine.

Having MS does not necessarily mean that someone is immunocompromised. According to the National Multiple Sclerosis Society, people taking the following DMTs for MS have been found to have a reduced or absent response to the COVID-19 vaccines:

• Gilenya (fingolimod)
• Mayzent (siponimod)
• Zeposia (ozanimod)
• Ponvory (ponesimod)
• Lemtrada (alemtuzumab)
• Ocrevus (ocrelizumab)
• Kesimpta (ofatumumab)
• Any biosimilars of these medications — in some cases, the same drug is available under a different brand name

The National Multiple Sclerosis Society also provides guidance on timing MS medications and COVID-19 vaccines, depending on which disease-modifying therapy a person is taking.

If you believe you are immunocompromised, ask your doctor whether you might benefit from an additional dose of an mRNA COVID-19 vaccine.