Updated Sept. 24, 2024

Conversations About COVID-19 Vaccines

COVID-19 vaccines have been shown to be safe and effective.

Rigorous testing has demonstrated the safety of the COVID-19 vaccines and the Centers for Disease Control and Prevention (CDC) continue to monitor for safety concerns. All available vaccines are effective at preventing severe disease, hospitalization and death caused by COVID-19.


COVID-19 vaccines have been thoroughly tested—just like all other vaccines.

COVID-19 vaccines in use today have gone through Phase 1, 2 and 3 clinical trials after being developed and tested for safety with the same rigorous process used for other vaccines. Phase 1 and 2 trials cannot begin until the vaccines are thoroughly tested in the lab. After testing with smaller groups of people during Phases 1 and 2, Phase 3 trials begin with a larger group of people. All data collected must be reviewed by an independent data safety monitoring board to ensure the vaccine meets FDA criteria. This is followed by additional reviews by the FDA, CDC and other groups.

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No corners were cut when developing COVID-19 vaccines, only red tape.

It was possible to produce COVID-19 vaccines more quickly than usual—without skipping steps in research or safety—for a few reasons.

  • The time between Phase 1, 2 and 3 trials was shortened. Usually, there is more time between Phase 2 and 3 to allow time for planning and to raise money for production. In this case, everyone involved, including the FDA, worked seven days a week to review data as soon as it was ready and kept planning processes moving.
  • The government paid for manufacturing so that companies would not have to raise money to ramp up vaccine production.

In this way, it was possible to overlap some steps, without skipping any of the normal safety procedures.

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How Can Vaccine and Antibody Studies Move So Quickly and Still Be Safe? | Español

Systems are in place to continue monitoring the vaccines’ safety.

Hundreds of millions of doses of COVID-19 vaccines have been given in the United States, and according to the CDC, serious safety problems have been rare. Safety monitoring systems have found three, very rare types of health problems after vaccination. These are thrombosis with thrombocytopenia syndrome (TTS), which was linked to the Johnson & Johnson vaccine that is no longer available, severe allergic reactions, which have occurred on very rare occasions with all COVID-19 vaccines, and myocarditis and pericarditis (inflammation of the heart and lining of the heart), which has been associated with the mRNA vaccines (Pfizer and Moderna) and the Novavax (protein subunit) vaccine.

Cases of myocarditis linked to COVID-19 vaccines are extremely rare and have been reported primarily in adolescents and young adults. The CDC and its partners continue to monitor these reports and review data and medical records to learn about what caused the illnesses to determine if there is a link to vaccination.

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Most patients who received care responded well to treatment and rest and quickly felt better. These reactions are known, very rare and typically treatable, and the FDA and CDC continue to emphasize that getting vaccinated is a much safer option than the unknown outcomes of a COVID-19 infection.

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Safety monitoring—how you can help

Side effects can be reported to the Vaccine Adverse Event Reporting System (VAERS) at vaers.hhs.gov. Watch this video to learn more about VAERS.


    mRNA vaccines have been studied for more than 20 years.

    mRNA vaccines have been in development and studied since the early 1990s for diseases including flu, Zika virus and rabies. Cancer research has also used mRNA to teach the immune system to target cancer cells. See the COVID-19 Vaccine Timeline to learn more.

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    The Novavax vaccine relies on older, more familiar vaccine technology.

    The Novavax vaccine is a protein subunit vaccine—a type of vaccine that has been used and studied for decades. This type of vaccine contains pieces (proteins) of the virus that causes COVID-19. These are pieces of what is known as the “spike protein,” which is harmless and cannot do anything on its own. Along with the proteins, the vaccine also contains fats and sugars and an adjuvant, which is an ingredient that helps the immune system respond to the spike protein in the future. Once the body learns how to recognize these proteins, it can respond to any actual virus proteins in the future and protect you from COVID-19. This vaccine does not contain mRNA.

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    Long-term health problems are extremely unlikely following any vaccination.

    Many people have questions about the long-term effects of the COVID-19 vaccines, simply because they’re so new. But there are a couple of things to keep in mind. First, the technology used to develop the vaccines is not new. Both mRNA and viral vector vaccines have been around—and studied—for decades.

    Second, long-term health problems following any vaccination are extremely unlikely. According to the CDC, vaccine monitoring has shown us that in the rare event that side effects do occur, they typically show up within six weeks of vaccination. The FDA required that all COVID-19 vaccines be studied for at least eight weeks after the final dose.

    Since those periods of observation, several months have elapsed and millions of people have received the vaccines and long-term side effects remain unlikely. The CDC and FDA continue to monitor for safety issues so that swift action can be taken if any concerns arise.

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    Safety of COVID-19 Vaccines


      The vaccines will not cause you to become infected with COVID-19 nor can they affect your DNA.

      None of the vaccines can cause you to become infected with COVID-19. They can only prevent infection. None of the vaccines contain live SARS-CoV-2, the virus that causes COVID-19. None of the vaccines can change your DNA. The vaccines either contain mRNA, harmless pieces of protein, or an adenovirus that cannot replicate. The vaccines use these tools to teach your body to defend itself from SARS-CoV-2. See the vaccination FAQ for more information about how groundbreaking research has delivered safe, effective COVID-19 vaccines.

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        There is no evidence to suggest that any of the vaccines cause infertility or interfere with pregnancy.

        At this time, there is no evidence to suggest that the COVID-19 vaccines, or any vaccines, cause fertility problems or other reproductive issues.

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        The vaccines may cause side effects for about 24-48 hours.

        Not everyone experiences symptoms after vaccination, but those who do may experience pain, redness or swelling at the injection site and tiredness, headache, muscle pain, chills, fever and/or nausea. Talk with your employer about planning for this and scheduling time off if you need to or consider scheduling your vaccination before a day off. Plenty of appointments are available in Spokane County at clinics and pharmacies.


        It isn’t always easy to talk about vaccination with family, but there are ways to have respectful, open conversations.

        Talking about COVID-19 vaccination can be a touchy subject. Watch this video with public health nurse Kira Lewis, from Spokane Regional Health District, for pointers.


        Sources

        COVID-19 Vaccines for Moderately to Severely Immunocompromised People. Centers for Disease Control and Prevention. Updated August 30, 2024. Accessed September 24, 2024. https://www.cdc.gov/covid/vaccines/immunocompromised-people.html

        Emergency Use Authorization for Vaccines Explained. U.S. Food & Drug Administration. Updated November 20, 2020. Accessed September 24, 2024. https://www.fda.gov/vaccines-blood-biologics/vaccines/emergency-use-authorization-vaccines-explained

        How Can Vaccine and Antibody Studies Move So Quickly and Still Be Safe? Washington State Department of Health. Video. January 15, 2021. Accessed September 24, 2024. https://www.youtube.com/watch?v=UXaJmIr1l8k

        Long-term Side Effects of COVID-19 Vaccine? What We Know. Parents PACK Newsletter. Children’s Hospital of Philadelphia. February 3, 2021. Updated March 9, 2022. Accessed September 24, 2024. https://www.chop.edu/parents-pack/parents-pack-newsletter/newsletter-archive/long-term-side-effects-covid-19-vaccine

        Boyle, P. mRNA Technology Promises to Revolutionize Future Vaccines and Treatments for Cancer, Infectious Diseases. Association of American Medical Colleges. March 29, 2021. Accessed September 24, 2024. https://www.aamc.org/news-insights/mrna-technology-promises-revolutionize-future-vaccines-and-treatments-cancer-infectious-diseases

        COVID-19 Vaccine Basics. Centers for Disease Control and Prevention. last modified July 12, 2024. https://www.cdc.gov/covid/vaccines/how-they-work.html

        Questions and Answers About COVID-19 Vaccines. Children’s Hospital of Philadelphia. Updated April 24, 2024. https://www.chop.edu/centers-programs/vaccine-education-center/making-vaccines/prevent-covid

        Staying Up to Date with COVID-19 Vaccines. Centers for Disease Control and Prevention. Updated July 3, 2024. https://www.cdc.gov/covid/vaccines/stay-up-to-date.html