If You Got the Johnson & Johnson Vaccine, You Can Now Get a Second mRNA Booster

If you received the Johnson & Johnson Janssen COVID-19 vaccine, you likely already know that your primary dose and booster schedule is different than Pfizer or Moderna recipients. J&J makes the only single-shot COVID-19 vaccine in use in the U.S., but that doesn't quite mean it's a one-and-done situation.

The Centers for Disease Control and Prevention recommend that J&J vaccine recipients get a booster of the vaccine at least two months after the initial dose (compared to five months for Pfizer and Moderna). The organization recommends J&J recipients receive an mRNA (i.e. Moderna or Pfizer) booster in most cases, though a J&J booster is an option in some situations (for example, due to an allergy or limited supply).

On March 29, the CDC further updated its guidance by making J&J vaccine and booster recipients eligible for a second booster shot of one of the mRNA vaccines.

The announcement, made in conjunction with authorization of a second booster shot for immunocompromised people and people over 50, comes on the back of new vaccine effectiveness research. A CDC study found that J&J vaccine effectiveness spiked when one J&J dose was followed by one mRNA dose. Vaccine effectiveness against emergency department or urgent care visits was 54 percent after two J&J doses, for example, but jumped to 79 percent after one J&J and one mRNA dose. This is comparable to the 83 percent effectiveness of two mRNA doses, and hospitalization numbers were similar. The data was analyzed from over 80,000 emergency room or urgent care visits and more than 25,000 hospitalizations in 10 states from mid-December 2021 to March 7, 2022, a time when the Omicron variant was dominant in the U.S.

With this new data in hand, the CDC announced that "adults who received a primary vaccine and booster dose of Johnson & Johnson's Janssen COVID-19 vaccine at least 4 months ago may now receive a second booster dose using an mRNA COVID-19 vaccine." This builds on prior research on mixing COVID-19 vaccines (aka getting a booster shot from a different brand than your primary dose or doses), which found this practice to be safe and effective.

The CDC study also pointed out that, just as any of the three vaccines is better than none, any booster shot is better than skipping it altogether. In the case of J&J, a single dose of the vaccine demonstrated 24 percent effectiveness against emergency department or urgent care visits due to COVID-19. With a second J&J shot, that number increased by 30 percent. It's another reminder to stay on top of your vaccines and boosters and, if you're a J&J recipient, look into scheduling an mRNA booster appointment when you can.

— Additional reporting by Angelica Wilson

POPSUGAR aims to give you the most accurate and up-to-date information about the coronavirus, but details and recommendations about this pandemic may have changed since publication. For the latest information on COVID-19, please check out resources from the WHO, CDC, and local public health departments.