Vaccine-preventable infections (VPIs) in pediatric hematopoietic cell transplantation (HCT) recipients cause significant morbidity, health care burden, and mortality.
Dana Danino, MD, and colleagues presented their evaluation of the prevalence and epidemiology of pediatric VPI-associated hospitalizations occurring within 5 years post HCT at the annual meeting of the European Society for Paediatric Infectious Diseases, held virtually this year.
“Pediatric HCT recipients are at increased risk of VPIs, and HCT recipients have poor outcomes from VPIs, compared with the general population,” explained Dr. Danino, of the department of pediatrics, and divisions of infectious diseases and host defense at the Ohio State University, Columbus. “However, the contemporary prevalence, risk factors, morbidity and mortality resulting from VPIs in children post HCT are not well known.”
Their epidemiological study, using the Pediatric Health Information System (PHIS) database, identified all children under 18 years that underwent allogeneic or autologous HCT in an 8-year period. A total of 9,591 unique HCT recipients were identified.
The researchers demonstrated that 7.1% of this cohort were hospitalized for a VPI in the first 5 years post HCT. Dr. Danino explained that 67% of VPI hospitalizations occurred during the first year, at a median of 222 days, and 22% of VPIs occurred during the initial HCT admission.
As to the type of infection, Dr. Danino and colleagues found that, the prevalence of VPI hospitalizations were highest for influenza, followed by varicella and invasive pneumococcal infections. They identified no hospitalizations due to measles or rubella during the study period.
The study findings revealed that the influenza infections occurred a median 231 days post HCT; varicella infections occurred a median 190 days; and invasive pneumococcal infections occurred a median 311 days post HCT.
“When we did a multivariate analysis by time post HCT, we found that age at transplantation, primary immune deficiency as an indication for transplantation, and graft versus host disease were independent predictors of VPIs during the initial HCT admission,” said Dr. Danino.
Children with a VPI who spent longer in hospital were more likely to be admitted to an ICU and have higher mortality, compared with children without a VPI diagnosis.
“VPIs led to longer duration of hospitalization, higher rates of ICU admission, and higher mortality, compared to HCT recipients without VPIs,” Dr. Danino explained. It was not possible in this retrospective study to determine whether increased mortality was VPI related.
These results underline the seriousness of infections in vulnerable children after HCT. Dr. Danino concluded by saying that “efforts to optimize vaccination strategies early post HCT are warranted to decrease VPIs.”
Dr. Danino had nothing to disclose.