Safety Monitoring of an Additional Dose of COVID-19 Vaccine — U.S. August 12–September 19, 2021

Details

• Personal Author:
  Hause, Anne M. ; Baggs, James ; Gee, Julianne ; Marquez, Paige ; Myers, Tanya R. ; Shimabukuro, Tom T. ; Shay, David K.
• Corporate Authors:
  CDC COVID-19 Response Team
• Description:
  What is already known about this topic? Among 306 Pfizer-BioNTech clinical trial participants, adverse reactions after dose 3 were similar to those after dose 2.
  
  What is added by this report? During August 12–September 19, 2021, among 12,591 v-safe registrants who completed a health check-in survey after all 3 doses of an mRNA COVID-19 vaccine, 79.4% and 74.1% reported local or systemic reactions, respectively, after the third dose; 77.6% and 76.5% reported local or systemic reactions after the second dose, respectively.
  
  What are the implications for public health practice? Voluntary reports to v-safe found no unexpected patterns of adverse reactions after an additional dose of COVID-19 vaccine. CDC will continue to monitor vaccine safety, including for additional COVID-19 doses.
  
  On August 12, 2021, the Food and Drug Administration (FDA) amended Emergency Use Authorizations (EUAs) for the Pfizer-BioNTech and Moderna Covid-19 Vaccines to authorize administration of an additional dose after completion of a primary vaccination series to eligible persons with moderate to severe immunocompromising conditions (1,2). On September 22, 2021, FDA authorized an additional dose of Pfizer-BioNTech vaccine ≥6 months after completion of the primary series among persons aged ≥65 years, at high risk for severe COVID-19, or whose occupational or institutional exposure puts them at high risk for COVID-19 (1). Results from a phase 3 clinical trial conducted by Pfizer-BioNTech that included 306 persons aged 18–55 years showed that adverse reactions after receipt of a third dose administered 5–8 months after completion of a 2-dose primary mRNA vaccination series were similar to those reported after receipt of dose 2; these adverse reactions included mild to moderate injection site and systemic reactions (3). CDC developed v-safe, a voluntary, smartphone-based safety Surveillance system, to provide information on adverse reactions after COVID-19 vaccination. Coincident with authorization of an additional dose for persons with immunocompromising conditions, the v-safe platform was updated to allow registrants to enter information about additional doses of COVID-19 vaccine received. During August 12–September 19, 2021, a total of 22,191 v-safe registrants reported receipt of an additional dose of COVID-19 vaccine. Most (97.6%) reported a primary 2-dose mRNA vaccination series followed by a third dose of the same vaccine. Among those who completed a health check-in survey for all 3 doses (12,591; 58.1%), 79.4% and 74.1% reported local or systemic reactions, respectively, after dose 3, compared with 77.6% and 76.5% who reported local or systemic reactions, respectively, after dose 2. These initial findings indicate no unexpected patterns of adverse reactions after an additional dose of COVID-19 vaccine; most of these adverse reactions were mild or moderate. CDC will continue to monitor vaccine safety, including the safety of additional doses of COVID-19 vaccine, and provide data to guide vaccine Rec.and protect public Health
  
  Suggested citation for this article: Hause AM, Baggs J, Gee J, et al. Safety Monitoring of an Additional Dose of COVID-19 Vaccine — U.S. August 12–September 19, 2021. MMWR Morb Mortal Wkly Rep. ePub: 28 September 2021.
  
  mm7039e4.htm?s_cid=mm7039e4_w
  
  mm7039e4-H.pdf
  
  
• Subjects:
  CoronaVirus Infections/Prevention & Control COVID-19 Vaccines COVID-19/Prevention & Control Immunization, Secondary Patient Safety Safety
• Source:
  MMWR: Morbidity and Mortality Weekly Report 2021; v. 70 Early Release
• Series:
  Weekly Report: Morbidity and Mortality Weekly Report (MMWR)
• ISSN:
  0149-2195 (print) ; 1545-861X (digital)
• Document Type:
  Journal Article
• Name as Subject:
  Pfizer-BioNTech COVID-19 Vaccine
• Pages in Document:
  6 pdf pages
• Volume:
  70
• Collection(s):
  Morbidity and Mortality Weekly Report (MMWR)
• Main Document Checksum:
  urn:sha-512:4cd45dd6ebd389b8bd12b26f2bc4845c6a3e3de8831e4c0c368167717d15eb4c6fbe421e212ec95a37f6eb197ddfb6c732e3d0f29d72a7b25c9425d805b70cee
• Download URL:
  https://stacks.cdc.gov/view/cdc/110118/cdc_110118_DS1.pdf
• File Type:
  [PDF - 530.07 KB ]