All You Need to Know About COVID-19 Booster Shots

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All You Need to Know About COVID-19 Booster Shots

Skye Kalil

Written by Skye Kalil

Skye Kalil

Skye Kalil

Skye likes writing about mental health, nutrition, and wellness. She is passionate about sharing information that will educate, and positively affect people's lives.

Raul Zambrano, MD

Reviewed by Raul Zambrano, MD

January 31, 2023 / Read Time 4 minutes

*NOTE:  Due to a lack of scientific data at this time, PlushCare physicians do not prescribe ivermectin, hydroxychloroquine, or azithromycin/other antibiotics to treat COVID-19.

COVID-19 booster information is frequently changing. Information in this article was correct at the time of publishing.

What Is a COVID Booster Shot?

The COVID booster shot is an additional dose of the COVID-19 vaccine to boost immunity. They are given to people who have completed the initial COVID-19 vaccination series, to reinvigorate the immune system and increase circulating antibodies. This decline in immunity/antibodies after initial vaccination is common in many vaccines.

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How Does a COVID Booster Shot Work?

The COVID initial vaccination series works by first building up the body's immune system, called the priming effect. The idea is that immune-fighting cells have already been primed, then the booster shot increases the vaccination's protection over time by acting on a primed immune system, rather than starting from scratch. This allows for a stronger immune response and better protection against COVID.

COVID-19 is not the first disease to need booster shots. The priming effect has been shown with many other FDA-approved vaccines, such as tetanus, whooping cough, or Hepatitis B. Booster shots are beneficial by helping improve immunity.

Who Can Get a COVID Booster Shot?

Everyone ages 5 and older can get the original (monovalent) COVID booster shot at least five months after completing their primary COVID-19 vaccination series, according to the CDC.

The FDA and CDC have also officially authorized one bivalent COVID-19 booster dose for everyone ages 6 months and older, with the exception of children aged 6 months to 4 years who have received a 3-dose Pfizer-BioNTech primary series. The bivalent booster doses include the updated Pfizer-BioNTech or Moderna booster and offer protection against the original COVID-19 strain as well as Omicron variants.

The FDA and CDC approved people getting booster shots that are different from the COVID-19 vaccine they first received (allowing mix-and-match dosing for boosters).

According to the CDC, Pfizer-BioNTech or Moderna (mRNA COVID-19 vaccines) are clinically preferred in most situations.

If you have questions about booster shots, you can book an appointment with a PlushCare doctor to discuss if a booster shot is appropriate. These recommendations are changing regularly as more information becomes available; always check the CDC website prior to scheduling your booster shot for indications and requirements. 

The U.S. Food and Drug Administration (FDA) and the CDC's Advisory Committee on Immunization Practices (ACIP) are each conducting ongoing assessments on the safety and effectiveness of a booster dose against waning COVID-19 immunity, and protection against the Delta variant and the Omicron variant. 

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    Book on our free mobile app or website.

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What Are the Side Effects of a COVID Booster Shot?

The side effects of a COVID booster shot are similar to the regular COVID shots. The booster shot is not expected to have any additional symptoms. The CDC reports that reactions after the booster shot were similar to those of the two-dose series. 

Side effects after the booster shot may include:

  • Redness and swelling around the injection site

  • Tiredness

  • Headache

  • Muscle and joint pain

  • Chills

Should You Get a Booster Shot If You Currently Have COVID-19 or COVID-19 Symptoms?

If a person currently has COVID-19, or experiences what could be COVID-19 symptoms, they should not get a booster shot until after fully recovering from COVID-19. This means waiting until after all symptoms have subsided and resolved, and until the person no longer has to self-isolate. Talk to your doctor or primary care provider and review the latest CDC guidelines before getting a booster.

Is There a Difference Between a Booster and an Additional Dose of the COVID-19 Vaccine?

There is a difference between a booster shot and an additional dose of the COVID-19 vaccine. The main difference is who gets them, when, and why. 

  1. Those who are immunocompromised can get an additional dose of the vaccine (the "third dose" in certain vaccine series) to boost immunity and achieve the same level of protection that occurs in those who are not immunocompromised.

  2. Individuals with normal immune systems who have previously been fully vaccinated may be eligible for a booster dose to compensate for the waning in immunity that naturally occurs over time.

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    Book on our free mobile app or website.

    Our doctors operate in all 50 states and same day appointments are available every 15 minutes.

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    See a doctor, get treatment and a prescription at your local pharmacy.

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    Use your health insurance just like you normally would to see your doctor.

COVID-19 Vaccine for Immunocompromised People

Currently, additional doses of the COVID 19 vaccine are available and recommended by the CDC for moderate to severely immunocompromised patients. 

Recent studies have found lower COVID-19 vaccine effectiveness for people with immunocompromised immune systems, ranging from 59% to 72% according to the CDC. This is compared to 90% to 94% effectiveness for people who are not immunocompromised.

The CDC provides the following list for those who fall into the immunocompromised category: 

  • Individuals receiving active cancer treatment for tumors or cancers of the blood.

  • Those who received an organ transplant and are taking medicine to suppress the immune system.

  • People who have received a stem cell transplant within the last two years or are taking medication to suppress the immune system.

  • Patients with moderate or severe primary immunodeficiency (such as DiGeorge syndrome, Wiskott-Aldrich syndrome).

  • Those with advanced or untreated HIV infection.

  • Individuals undergoing treatment with high-dose corticosteroids or other drugs that may suppress your immune response.

If any of the conditions in the list above apply to you, the CDC has recommended that you get a third dose of the COVID shot to increase your immunity. 

Can I Get an Additional Shot or Should I Talk to a Doctor First? Do I Need to Prove I Am Immunocompromised?

If you have questions about COVID booster shots, speak with a PlushCare doctor to learn more and find out your level of risk. You can also meet with a PlushCare doctor online if you are immunocompromised or immunosuppressed and are considering a third shot.

A doctor's note stating that you are immunocompromised may not be required for a third shot, though doctors at PlushCare may provide a doctor's note if you need one and you qualify.

Book an online appointment with a trusted board-certified doctor at PlushCare below.

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    Book on our free mobile app or website.

    Our doctors operate in all 50 states and same day appointments are available every 15 minutes.

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    See a doctor, get treatment and a prescription at your local pharmacy.

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    Use your health insurance just like you normally would to see your doctor.

Read More About COVID-19 Booster Shots

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