Since they’ve been introduced, COVID-19 vaccines have been the best way to protect yourself and others from the coronavirus. But lately, we have been hearing about booster shots, and you may be wondering if you should get one.

This may also prompt questions: What’s the difference between a booster shot and an immunocompromised dose? Why do you need another shot? Is the vaccine still effective?

We answer these questions and more below.

Booster shot vs. immunocompromised dose: Is there a difference?

Yes. There’s a difference between COVID-19 vaccine booster shots and immunocompromised doses. Though they are both an additional shot of the vaccine, they’re used for different reasons which we’ll get into in the following sections.

What is a COVID-19 vaccine booster shot?

The COVID-19 vaccine booster shot is a dose of the vaccine that’s used to bring a vaccine back up to the original level of effectiveness and extend the length of protection.

Why would I need a COVID-19 vaccine booster shot?

Most vaccines lose some of their effectiveness over time. That’s why there are booster shots for illnesses such as chickenpox, tetanus, mumps and measles, to name a few – and why you should get a flu shot every year.

By recommending booster shots, health officials hope to continue the strong protection that people currently have against COVID-19.

Who is eligible for a COVID-19 vaccine booster shot?

All fully vaccinated people over the age of 12 are eligible to receive a COVID-19 booster shot.

Are booster shots different than the vaccine shots?

The booster shots are a dose of the same, approved COVID-19 vaccines. The Pfizer and Johnson & Johnson boosters contain the same dose as the original vaccine, while the Moderna booster is a half-dose of the original.

When will COVID-19 vaccine boosters be available?

Booster shots for all COVID-19 vaccines are now available.

Which booster shot can I get? Can you mix vaccines?

According to the Centers for Disease Control and Prevention (CDC), mRNA booster shots (Pfizer or Moderna) are recommended over the Johnson & Johnson booster shot – regardless of your initial COVID-19 vaccine.

As far as which of the mRNA booster shots you can get, there’s some flexibility. Getting another dose of your initial COVID-19 vaccine will, undoubtably, boost your protection. But studies show that a mix-and-match approach for booster shots can be valuable, especially if the vaccines are based on different technology. For example, someone who originally received the viral vector vaccine from Johnson & Johnson may get even more protection from a booster dose of a mRNA vaccine like Moderna.

However, any booster shot will increase your protection against COVID-19. So, we recommend getting the booster shot that’s available to you.

When should I get a COVID-19 vaccine booster shot?

The timing of your booster shot depends on your initial vaccine and your age.

Age Type of initial vaccine Timing after second dose Type of booster vaccine you can get
12 - 17 Pfizer 5 months Pfizer
18 and older Pfizer 5 months Any
18 and older Moderna 5 months Any
18 and older Johnson & Johnson 2 Months Any

What is a COVID-19 vaccine immunocompromised dose?

For most people, receiving the prescribed doses of the COVID-19 vaccine (two for Moderna and Pfizer; one for Johnson & Johnson) causes enough of an initial immune system response to protect them from falling ill with COVID-19.

But for people with weakened immune systems, the initial vaccine may not produce enough protective antibodies to prevent them from getting the disease – especially with new, more contagious strains of COVID-19 emerging. In these cases, people may need an additional dose of a COVID-19 vaccine for full protection.

Who is eligible for a COVID-19 vaccine immunocompromised dose?

People over the age of 5 years old who are moderately to severely immunocompromised and received the Moderna or Pfizer COVID-19 vaccine are eligible to receive an additional dose 28 days after their second dose. You may be considered immunocompromised if you:

  • Had an organ transplant
  • Had stem cell transplants within the past two years
  • Have severe primary immunodeficiency
  • Are being treated for active cancer
  • Have advanced or untreated HIV
  • Are being treated with drugs that may suppress your immune system, such as high-dose corticosteroids

When will COVID-19 vaccine immunocompromised doses be available?

Immunocompromised doses of the Pfizer and Moderna vaccines are available now.

Which immunocompromised dose can I get?

Your immunocompromised dose should be from the same vaccine manufacturer as your initial series. For example, if you received two doses of Pfizer previously, your additional dose should be Pfizer. If you received two doses of Moderna, your additional dose should be Moderna.

When should I get an immunocompromised dose?

Age Type of initial vaccine Timing after second dose Type of booster vaccine you can get
5 - 17 Pfizer 28 days Pfizer
18 and older Pfizer and Moderna 28 days Same as initial vaccine

Even after you get an immunocompromised dose, it’s still recommended you continue to take other steps to avoid getting COVID-19, including wearing a mask and avoiding large crowds.

If you’re eligible for a third dose and received your initial vaccines through HealthPartners, you likely have already received an email or text message from us and can schedule your next dose online. But you don’t have to be a HealthPartners patient to schedule your immunocompromised dose.

If you’re not sure if you’re eligible, call one of our nurse lines – HealthPartners CareLine℠ at 800-551-0859 or the Park Nicollet Nurse Line at 952-993-4665.

Does the need for additional shots mean that the COVID-19 vaccine isn’t effective?

Absolutely not. The vaccines have always been effective and continue to prevent COVID-19. Rolling out boosters and additional doses demonstrates that we’re learning more about COVID-19 so we can keep communities healthy and control the spread of the coronavirus.

We know that the vaccines work. According to the CDC, unvaccinated people are about five times more likely to get COVID-19 than vaccinated people. If someone who is vaccinated gets breakthrough COVID-19, it’s extremely rare that they get a severe case that results in hospitalization. If you skip out on getting a COVID 19 vaccine, you’re over 10 times more likely to be hospitalized or die because of your symptoms.

But we also know that the COVID-19 vaccines may become less effective after a while. Again, this isn’t because the vaccines aren’t effective. Rather, this is what normally happens with many vaccines – the immune response can decrease over time. It’s also important to remember that since the vaccines were first made available, scientists have said there may be a need for booster shots at some point.

Getting vaccinated is still the best thing you can do to prevent COVID-19. And, getting a booster or immunocompromised dose can help extend your protection against the coronavirus.

Are COVID-19 vaccine booster shots and immunocompromised doses safe?

Yes. COVID-19 booster shots and immunocompromised doses are the same as your earlier doses. The COVID-19 vaccines are incredibly safe – they’ve protected millions of people against COVID-19, usually with few side effects.

What are the possible side effects of a COVID-19 vaccine booster shot or immunocompromised dose?

Do you remember the side effects you had with your initial vaccine dose(s)? Chances are that your side effects will be very similar this time around.

For most people, the common side effects are usually fatigue and feeling pain around where they got the shot. Less commonly, people experience headache, muscle pain, chills, fever and nausea. These side effects usually only last a couple days.

Moving forward as things change

It may seem like things with COVID-19 keep changing. And you’re not wrong. There are new strains of COVID-19 that are more infectious that are changing masking guidelines – even for the vaccinated – and moving up the timeline for booster shots. But you can help fight COVID-19 by getting a COVID-19 vaccine. And once you’re eligible, make sure to get your COVID-19 booster shot or immunocompromised dose as well.