This blog was originally posted in 2021. Some information may be out of date. For the latest updates on vaccines, testing, screening, visitor policy and post-COVID support, visit EEHealth.org/coronavirus.

COVID-19 isn’t going away anytime soon. But we have a powerful tool at our disposal that’s saving lives. The COVID-19 vaccine is preventing serious illness and keeping us out of the hospital.

To date, 185 million people in the U.S. have been fully vaccinated against COVID-19. They received one of three COVID-19 vaccines: the two-dose Pfizer-BioNTech or Moderna mRNA vaccine, or the one-shot Janssen (J&J) vector vaccine. All three vaccines are protective against COVID-19.

For the mRNA vaccines, the time between the first and second shot is 21 days for Pfizer and 28 days for Moderna. In August 2021, research uncovered that immunocompromised people don’t always build the same level of immunity after the standard two mRNA vaccine doses like those with healthy immune systems do. The result?

A third dose was added to the initial vaccination series for certain individuals who are moderately to severely immunocompromised. The third shot applies to the mRNA vaccines and is recommended at least four weeks (28 days) after the second dose of either the Pfizer or Moderna vaccine.

Now, what about a COVID-19 booster shot?

With some of us several months out from being fully vaccinated, we’re now hearing about booster shots to stay protected. This is where it can get confusing. When do we need a booster shot? Who is eligible and which vaccine product is being used? Let’s try to clear it up.

What is a booster dose and why is it needed? 

The booster is intended to “boost” immunity, as research suggests that the level of virus-fighting antibodies starts to wane several months after getting the vaccine. Some research also suggests that with each new dose, the body makes higher quality antibodies that are better at blocking new variants.

The Centers for Disease Control and Prevention (CDC) states: “With the delta variant’s dominance as the circulating strain and cases of COVID-19 increasing significantly across the United States, a booster shot will help strengthen protection against severe disease in those populations who are at high-risk for exposure to COVID-19 or the complications from severe disease.”

Even without the boost, all the COVID-19 vaccines provide strong protection against hospitalization and death.

Who should get a COVID-19 vaccine booster?

The CDC recommends everyone age 16 and older should get a booster shot.

When should you get a booster?

• At least 6 months after you received your second Pfizer or Moderna shot
• At least 2 months after you received your single Janssen (J&J) shot

Which booster shot should you get?

For adults age 18 and older, any of the COVID-19 vaccines authorized in the United States can be used for the booster dose. Children age 16 and 17 are authorized to receive a Pfizer booster.

Read CDC recommendations here.

Still have questions about a COVID-19 booster shot?

If you have questions about getting a COVID-19 vaccine “booster” dose, ask your doctor.

Everyone age 5 and older is recommended to get vaccinated with the primary series, and everyone age 18 and older can now get a booster shot.

Haven’t been vaccinated yet? To date, 185 million people in the U.S. have been fully vaccinated against COVID-19, under the most intense safety monitoring in U.S. history. The evidence is clear and straight-forward. The best way to protect yourself from possible severe illness, long-term health consequences of infection, hospitalization or death is to get vaccinated.

Edward-Elmhurst has COVID-19 vaccine appointments available to ages 5 and older, including booster doses for ages 16 and older. It is easy to schedule a vaccine appointment. You do not need a MyChart account. Schedule your COVID-19 vaccine now.

The information in this article may change at any time due to the changing landscape of this pandemic. Read more about COVID-19.