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Among vaccine recipients during the Pfizer clinical trials, 8.8% reported experiencing any reaction they considered to interfere with daily activity; the most common symptoms were fatigue (4.2%), headache (2.4%), muscle pain (1.8%), chills (1.7%), and injection site pain (1.4%). Of note, more people experienced these side effects after the second dose than after the first dose.Among vaccine recipients during the Moderna clinical trials, 9.1% reported local injection site reaction and 16.5% reported side effects with the most common being including fever, headache, fatigue, and muscle aches and pains.Additionally, no specific safety concerns were identified for the Pfizer and Moderna vaccines in subgroup analyses by age, race, ethnicity, underlying medical conditions, or previous SARS-CoV-2 infection.
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Yes, the vaccines were tested on tens of thousands of people and have passed safety requirements in Phase I, Phase II and Phase III trials. Over 179 million people have gotten vaccinated in the United States so far.
For more safety information, visit the trustworthy sources below for in-depth and accurate information about vaccine safety and effectiveness.
At this time, Pfizer’s vaccine has been authorized for vaccinating those aged 5 and up.
The Moderna and J&J vaccines have only been authorized to vaccinate those ages 18 and up.
Learn more about COVID-19 vaccines for children and teens.
Yes. COVID-19 vaccination is recommended for all people 5 years and older, including people who are pregnant, breastfeeding, trying to get pregnant now, or might become pregnant in the future.
Evidence about the safety and effectiveness of COVID-19 vaccination during pregnancy has been growing. These data suggest that the benefits of receiving a COVID-19 vaccine outweigh any known or potential risks of vaccination during pregnancy.
Please visit CDC's COVID-19 Vaccines While Pregnant or Breastfeeding for updated information to help you make your decision.
The ingredients used in the mRNA vaccines developed by Pfizer and Moderna are simple. They contain mRNA, as well as lipids to ensure safe delivery of the mRNA that will initiate an immune response.Ingredients of the Janssen COVID-19 vaccine include: recombinant, replication-incompetent adenovirus type 26 expressing the SARS-CoV-2 spike protein, citric acid monohydrate, trisodium citrate dihydrate, ethanol, 2-hydroxypropyl-β-cyclodextrin (HBCD), polysorbate-80, sodium chloride.Although FDA approved adjuvants (aluminum salts) and preservatives (ethlymercury) have a history of safe use in vaccines, they were not used by Pfizer, Moderna or Janssen.
Pfizer’s vaccine is authorized for those age 5 and older. The Moderna and Johnson & Johnson vaccines are authorized for those 18 and older.The vaccines are not recommended for individuals who have experienced a serious reaction (e.g., anaphylaxis) to a prior dose of a COVID-19 vaccine or to any of its components. For information on vaccine components, refer to the manufacturers’ package inserts from Pfizer, Moderna and Johnson & Johnson.
No. None of the authorized and recommended COVID-19 vaccines or COVID-19 vaccines currently in development in the United States contain the live virus that causes COVID-19. This means that a COVID-19 vaccine cannot make you sick with COVID-19.
Yes. Although use of the J&J vaccine was temporarily paused in April 2021, following a thorough safety review, U.S health officials determined that the recommended pause should be lifted and use of the vaccine should resume.
The two agencies have determined the following:
CDC’s independent Advisory Committee on Immunization Practices met to discuss the latest data on TTS, hearing from the vaccine manufacturer Janssen and the COVID-19 Vaccine Safety Technical (VaST) Subgroup, as well as a risk benefit analysis. ACIP is committed to be vigilant and responsive to additional information that could impact the risk benefit analysis of any of these vaccines. Vaccine safety monitoring will continue and any new information about TTS will be brought to ACIP as needed.
The Missouri Department of Health and Senior Services updated the standing orders for the Janssen COVID-19 vaccine to indicate that either authorized mRNA COVID-19 vaccines (Pfizer or Moderna) are preferred over the Janssen COVID-19 vaccine for the prevention of COVID-19 in individuals ages 18 years and older due to the risk of thrombosis with thrombocytopenia or Guillain-Barre (GBS) following vaccination. Clients medically unable to receive the mRNA COVID-19 vaccine or would otherwise not be vaccinated against COVID-19 may request the Janssen vaccine, and a CCPHC nurse may determine if the client is eligible for the vaccine.
Yes, those who have or have a history of thrombocytopenia, who have or have a history of a low platelet count, prior surgery (cardiac, orthopedic, trauma), cardiovascular disease, oral contraceptive use or hereditary thrombophilia.
If you experience any of the following symptoms seek medical attention right away: Shortness of breath, chest pain, leg pain or swelling, backache, persistent abdominal pain, severe and persistent headaches, visual changes or easy bruising or tiny blood spots under the skin beyond the site of the injection.
The Missouri Department of Health and Senior Services updated the standing orders for the Janssen COVID-19 vaccine to indicate that either authorized mRNA COVID-19 vaccines (Pfizer or Moderna) are preferred over the Janssen COVID-19 vaccine for the prevention of COVID-19 in individuals ages 18 years and older due to the risk of thrombosis with thrombocytopenia or Guillain-Barre (GBS) following vaccination. Clients medically unable to receive the mRNA COVID-19 vaccine or who would otherwise not be vaccinated against COVID-19 may request the Janssen vaccine, and a CCPHC nurse may determine if the client is eligible for the vaccine.