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’ll need one.

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

We answer these questions and more below.

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

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

What is a COVID-19 booster shot?

The COVID-19 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 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 for some people, health officials hope to continue the strong protection that people currently have against COVID-19.

Who is eligible for a COVID-19 booster shot?

You’re eligible for a COVID-19 booster shot if you got the Pfizer COVID-19 vaccine and are one of the following:

  • Over the age of 65
  • Over the age of 18 and more likely to get infected because of your job
  • Over the age of 18 and at higher risk of getting severe COVID-19 due to health status or chronic conditions

Why aren’t COVID-19 boosters approved for everyone right now?

Basically, all the COVID-19 vaccines are still doing a great job protecting most people from even the new variants. In the unlikely event that someone gets breakthrough COVID-19, it’s extremely rare that they get a severe case that results in hospitalization.

Most people who are healthy don’t need a booster shot right now because they still have good protection. But if you’re at higher risk of catching a serious case of COVID-19, the additional immunity boost may help. That’s why Pfizer booster shots are being recommended for people who are at greater risk based on their age, health or the type of job they do.

Scientists are still looking at data for Moderna and Janssen (Johnson & Johnson) booster shots. They are also evaluating the need for Pfizer booster shots for other age and risks groups.

When will COVID boosters be available?

The Pfizer booster shot is currently available.

When should I get a COVID-19 booster shot?

Right now, the recommendation is that eligible people get a booster shot six months after their second dose of the Pfizer vaccine. If you’re not currently eligible for a booster, be patient. Scientists are working to determine when you’ll need a booster or if you’ll need one at all.

What is a COVID-19 vaccine third dose for people who are immunocompromised?

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 the vaccine for full protection.

Right now, only immunocompromised doses for the Moderna and Pfizer vaccines are available. That’s why immunocompromised doses are often referred to as third doses. Scientists are still assessing the need for an immunocompromised dose of the Johnson & Johnson vaccine.

Who is eligible for a COVID-19 immunocompromised dose?

People who are moderately to severely immunocompromised, and received the Moderna or Pfizer COVID-19 vaccine, are eligible to receive a third dose once it’s been 28 days since 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 immunocompromised doses be available and when should you get one?

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

If you’re eligible, consider getting your immunocompromised dose if it’s been at least 28 days since your last 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 are 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 is not 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. COVID-19 is increasingly becoming a pandemic of the unvaccinated. According to the Centers for Disease Control and Prevention (CDC), unvaccinated people are about five times more likely to get COVID-19 than vaccinated people. There’s also a huge difference in the severity of symptoms between vaccinated and unvaccinated people. If you skip out on getting a COVID 19 vaccine, you are over 10 times more likely to be hospitalized or die.

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, for some people, getting a booster or immunocompromised dose will provide additional protection in the future.

Which vaccines offer booster shots or immunocompromised doses?

Right now, Pfizer and Moderna offer immunocompromised doses, and Pfizer has booster shots. Scientists are currently evaluating data for Johnson & Johnson and Moderna booster shots, and for Johnson & Johnson immunocompromised doses.

Which additional dose can I get? Can you mix vaccines?

You should only get a booster shot or an immunocompromised dose if you are eligible. Even then, all your doses should be from the same vaccine. However, if you’ve had an mRNA vaccine (Pfizer or Moderna) and can’t find an immunocompromised dose of the same vaccine, it may be okay to get a shot of the other mRNA vaccine.

Are COVID-19 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 booster shot or third dose?

Do you remember the side effects you had with your vaccine doses? 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 for some people. But you can help fight COVID-19 by getting a COVID-19 vaccine. And, if it’s recommended, get the COVID-19 boost shot or immunocompromised dose as well.