Trivalent Inactivated Influenza Vaccine Is Not Associated With Sickle Cell Crises in Children

Abstract

Background and Objectives: Children with sickle cell disease are considered at high risk for complications from influenza infection and are recommended to receive annual influenza vaccination. However, data on the safety of influenza vaccination in children with sickle cell anemia are sparse. Methods: Using a retrospective cohort of children aged 6 months to 17 years in 8 managed care organizations that comprise the Vaccine Safety Datalink and who had a diagnosis of sickle cell anemia from 1999 to 2006, we conducted matched case-control and self-controlled case series studies to examine the association of trivalent inactivated influenza vaccination with hospitalization for sickle cell crisis in the 2 weeks after vaccination. Results: From an original pool of 1085 pediatric subjects with a diagnosis of sickle cell anemia, we identified 179 children with at least 1 sickle cell crisis during any influenza season (October 1–March 31). In the matched case-control study (matching on age category, gender, Vaccine Safety Datalink site, and season), the odds ratio of hospitalization for a crisis in vaccinated compared with unvaccinated children was not significant: 1.3 (95% confidence interval 0.8–2.2). In the self-controlled case series study of hospitalized cases, the incident rate ratio for hospitalization with sickle cell crisis in the 2 weeks after trivalent inactivated influenza vaccination was also not significant: 1.2 (95% confidence interval 0.75–1.95). Conclusions: This large cohort study did not find an association of influenza vaccination and hospitalization for sickle cell crises in children with sickle cell anemia.

Potential Impact of Co-Infections and Co-Morbidities Prevalent in Africa on Influenza Severity and Frequency: A Systematic Review

“…Influenza vaccines are generally considered safe among individuals with sickle cell disease; however, one study suggested a 7- to 9-fold increased risk of hospitalization for sickle cell anemia after administration of trivalent inactivated vaccine [61]. Follow-up studies by the same group did not find increased hospitalizations for sickle cell crises in adults [62] or children [63] after influenza vaccination. No vaccine effectiveness or efficacy studies among persons with sickle cell disease have been conducted.…”

Preventive Care Delivery to Young Children With Sickle Cell Disease

“…3,4 The mechanism underlying this enhanced risk is incompletely understood, but may involve influenza: 1) compromising respiratory tract mucosal immunity; 36 2) causing acute chest syndrome; 37 and 3) provoking fever which results in precautionary admission to rule out bacterial sepsis. Fortunately, influenza immunization is both safe 38,39 and immunogenic 39,40 in children with SCD, and is efficacious in children generally. 8 Influenza immunization has been recommended for children with SCD by the Advisory Committee on Immunization Practices of the CDC since 1978, 41 and is now recommended for all children over 6 months of age.…”

Transgenic sickle cell disease mice have high mortality and dysregulated immune responses after vaccination

“…Even when a vaccine is routinely administered as part of the standard vaccination schedule, such as is the case with the trivalent inactivated influenza (TIV) vaccine, controversy may arise pertaining to its safety in people with uncommon diseases. Indeed, recent retrospective studies using the vaccine safety datalink project have indicated that the TIV vaccine is not associated with hospitalization in children or adults with SCD ( 10 , 11 ); however, a previous report by this group had shown that people with SCD had more frequent fever or pain episodes resulting in an inpatient visit within two weeks of influenza vaccination than control subjects ( 12 ). To our knowledge, no published prospective studies have been conducted in humans or mice to definitively determine if vaccination is associated with adverse effects in SCD.…”