BACKGROUND: Ischemic stroke is a known complication of varicella disease. Although there have been case reports of ischemic stroke after varicella vaccination, the existence and magnitude of any vaccine-associated risk has not been determined. OBJECTIVE. The purpose of this work was to determine whether varicella vaccination is associated with an increased risk of ischemic stroke and encephalitis in children within 12 months after vaccination. PATIENTS AND METHODS: We conducted a retrospective cohort study based on computerized data from children 11 months through 17 years old enrolled for > or =12 months in the Vaccine Safety DataLink from 1991 through 2004. International Classification of Disease codes identified cases of ischemic stroke (433-436, 437.1, 437.4, 437.6, 437.8-437.9) and encephalitis (052.0, 323.5, 323.8-9). Cox regression was used to model the risk in the 12 months after vaccination relative to all other person-time. Covariates included calendar time, gender, and stroke risk factors (eg, sickle cell disease). RESULTS: Varicella vaccine was administered to 35.3% of the 3.2 million children in the cohort. There were 203 new inpatient ischemic stroke diagnoses, including 8 that occurred within 12 months after vaccination; there was no temporal clustering. The adjusted stroke hazard ratio was not elevated during any of the time periods in the 12 months after vaccination. Stroke was strongly associated with known risk factors such as sickle cell disease and cardiac disease. None of the 243 encephalitis cases occurred during the first 30 days after vaccination, and there was no association between encephalitis and varicella vaccination at any time in the 12 months after vaccination. CONCLUSION: Our retrospective cohort study of >3 million children found no association between varicella vaccine and ischemic stroke.
BACKGROUND:Ischemic stroke is a known complication of varicella disease. Although there have been case reports of ischemic stroke after varicella vaccination, the existence and magnitude of any vaccine-associated risk has not been determined. OBJECTIVE. The purpose of this work was to determine whether varicella vaccination is associated with an increased risk of ischemic stroke and encephalitis in children within 12 months after vaccination. PATIENTS AND METHODS: We conducted a retrospective cohort study based on computerized data from children 11 months through 17 years old enrolled for > or =12 months in the Vaccine Safety DataLink from 1991 through 2004. International Classification of Disease codes identified cases of ischemic stroke (433-436, 437.1, 437.4, 437.6, 437.8-437.9) and encephalitis (052.0, 323.5, 323.8-9). Cox regression was used to model the risk in the 12 months after vaccination relative to all other person-time. Covariates included calendar time, gender, and stroke risk factors (eg, sickle cell disease). RESULTS: Varicella vaccine was administered to 35.3% of the 3.2 million children in the cohort. There were 203 new inpatient ischemic stroke diagnoses, including 8 that occurred within 12 months after vaccination; there was no temporal clustering. The adjusted stroke hazard ratio was not elevated during any of the time periods in the 12 months after vaccination. Stroke was strongly associated with known risk factors such as sickle cell disease and cardiac disease. None of the 243 encephalitis cases occurred during the first 30 days after vaccination, and there was no association between encephalitis and varicella vaccination at any time in the 12 months after vaccination. CONCLUSION: Our retrospective cohort study of >3 million children found no association between varicella vaccine and ischemic stroke.
Authors: Jana Shaw; Neal A Halsey; Adriana Weinberg; D Scott Schmid; Kirsten St George; William C Weldon; Michael Jordan; Patrick W Bryant; Philip S LaRussa; Deborah Y Bradshaw; Theresa Harrington; Anne Gershon Journal: J Pediatric Infect Dis Soc Date: 2017-09-01 Impact factor: 3.164
Authors: Heather J Fullerton; Nancy K Hills; Mitchell S V Elkind; Michael M Dowling; Max Wintermark; Carol A Glaser; Marilyn Tan; Michael J Rivkin; Luigi Titomanlio; A James Barkovich; Gabrielle A deVeber Journal: Neurology Date: 2015-09-30 Impact factor: 9.910
Authors: Regina Maria Rodrigues; Sylvia Costa Lima Farhat; Leandro Tavares Lucato; Tania Miyuki Shimoda Sakano; Paulo Scatulin Gerritsen Plaggert; Erasmo Barbante Casella; José Albino da Paz; Cláudio Schvartsman Journal: Einstein (Sao Paulo) Date: 2022-05-06
Authors: Harriet J Forbes; Elizabeth Williamson; Laura Benjamin; Judith Breuer; Martin M Brown; Sinéad M Langan; Caroline Minassian; Liam Smeeth; Sara L Thomas; Charlotte Warren-Gash Journal: PLoS One Date: 2018-11-21 Impact factor: 3.240