Health Conditions A-Z Infectious Diseases COVID-19 The Difference Between Pfizer and Moderna COVID-19 Vaccines By Korin Miller Korin Miller Korin Miller is a writer specializing in general wellness, sexual health and relationships, shopping, and lifestyle trends, with work appearing in Women’s Health, Self, Prevention, Daily Beast, and more. health's editorial guidelines Updated on January 10, 2024 Medically reviewed by Christopher Lee, MD Medically reviewed by Christopher Lee, MD Christopher Lee, MD is a board-certified cardiologist and internal medicine physician. learn more Close Ivan Pantic / Getty Images You can do a few things to protect yourself against COVID, like proper handwashing and wearing masks. However, the Pfizer-BioNTech, Moderna, and Novavax vaccines are the most effective choices for reducing your risk of getting sick from COVID. The three vaccines are all safe and approved by the U.S. Food and Drug Administration (FDA). However, it can be confusing to have different vaccines in use to protect against the same virus—especially when vaccines evolve and authorizations change. Here's what you need to know about how the Pfizer-BioNTech and Moderna vaccines compare and how both measure up to Novavax. Pfizer The Pfizer-BioNTech vaccine is a messenger RNA (mRNA) vaccine. This kind of vaccine contains lab-created mRNA that gives your body instructions for how to make spike proteins. Spike proteins are on the surface of viruses like the SARS-CoV-2 virus that causes COVID. Who Can Get It? Individuals aged 6 months and older can get the Pfizer-BioNTech vaccine. However, children 6 months to 11 years old get a different formulation than people aged 12 years and older. Also, this vaccine can be appropriate as long as you have not had severe allergic reactions to any of the vaccine ingredients. Doses and Timing In general, the vaccine doses—and when to get them—will vary depending on variables such as your vaccination status and age. However, people 12 years of age and older who have not been vaccinated yet or have previously received any COVID vaccine should receive one dose of an updated Pfizer-BioNTech vaccine. Also, if you have already had COVID, you can still get the vaccine. If you have an active COVID infection, wait until after your isolation period is complete to get vaccinated. Possible Side Effects As with any vaccine, some minor side effects are to be expected. The following are listed as some of the possible side effects: Chills Fever Headache Injection site pain, swelling, or redness Joint pain Muscle pain Nausea Swollen lymph nodes Tiredness There is also a potential for the vaccine to cause a severe allergic reaction that usually shows up within a few minutes up to an hour of getting a dose. Those with a history of severe allergic reactions should have a risk assessment conducted for the vaccine, and it's recommended that vaccines are administered in a setting where medical treatment is available. Effectiveness Research is still ongoing regarding how effective the Pfizer-BioNTech vaccine is. However, researchers previously found that this vaccine has been up to 95% effective against COVID. Moderna Another type of COVID-19 vaccine is the Moderna vaccine. This vaccine is the other mRNA vaccine option. Who Can Get It? The Moderna vaccine is available to people as young as 6 months old who have not had any serious allergic reactions to any of the vaccine's ingredients. Like the Pfizer-BioNTech vaccine, there are two different vaccine formulas for children between 6 months and 11 years old and for individuals at least 12 years old. Doses and Timing One dose of the updated Moderna vaccine is recommended for people 12 years old and older who have not been vaccinated. Individuals who already received a previous COVID vaccine should receive the same dosage. Possible Side Effects The following symptoms are listed as potential Moderna vaccine side effects: Chills or fever Headache Injection site pain, swelling, or redness Joint pain Muscle pain Nausea and vomiting Tiredness Effectiveness While the two mRNA vaccines have a slight difference in efficacy, it's not by much. One February 2021 study found the Moderna vaccine to be about 94.1% effective against COVID-19 in people ages 18 and older in a trial of 30,000 people. Novavax The Novavax vaccine is the only protein subunit vaccine. This type of vaccine contains pieces of spike protein and an adjuvant, a substance that helps your immune system's response to the protein. Who Can Get It? Unlike the Pfizer-BioNTech and Moderna vaccines, the Novavax vaccine is available only for people aged 12 and older. Anyone younger should receive one of the other two vaccines. Doses and Timing Individuals who are unvaccinated should receive one dose of the Novavax vaccine and then a second dose eight weeks later. You only need one dose if you've had previous COVID vaccines. Possible Side Effects The Novavax vaccine shares many side effects with the mRNA vaccines. Those side effects may include: Chills Decreased appetite Diarrhea Facial swelling Feeling unwell in general Hives Injection site pain, redness, itching, and swelling Lymph node pain and swelling Muscle or joint pain Effectiveness Both mRNA vaccines have a somewhat higher efficacy rate than the Novavax vaccine based on the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) for the vaccine. The GRADE review revealed that Novavax had an 89.6% rate of effectiveness against cases of COVID with symptoms. Cost COVID vaccines are free for everyone to receive, as long as they are eligible for them. Your immigrant status and whether you're insured or not will not affect your ability to get a COVID vaccine. COVID-19 Boosters Booster shots can help improve the effectiveness of vaccines that have already been administered. These shots are follow-up doses to your initial vaccine shots and help you stay up-to-date on your COVID vaccines. For people aged 5 and older, one dose of any of the COVID vaccines will keep you up to date and protected against COVID. Vaccines Continue to Evolve As variants of SARS-CoV-2 change, so will COVID vaccines. Additionally, the protection that COVID vaccines provide will be lower as time progresses following the shots. That's why it's important to stay up to date on COVID vaccines. Scientists have to create updated vaccines to help lower your risk of severe sickness from infections caused by newer variants. A Quick Review The Pfizer-BioNTech, Moderna, and Novavax vaccines are all free, safe, FDA-approved vaccines for COVID. They are also highly effective and share many of the same side effects, and booster shots for these vaccines are also part of the vaccination process. Just remember that vaccines will evolve as variants do, so stay up to date for protection against the active variants of SARS-CoV-2. The information in this story is accurate as of publication. However, as the situation surrounding COVID-19 continues to evolve, it's possible that some data have changed since publication. While Health is trying to keep our stories as up-to-date as possible, we also encourage readers to stay informed on news and recommendations for their own communities by using the CDC, WHO, and their local public health department as resources. Was this page helpful? Thanks for your feedback! Tell us why! Other Submit 13 Sources Health.com uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. 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