Safety of measles and pertussis-containing vaccines in children with autism spectrum disorders

ObjectivesTo determine whether children aged 4–7 years with a diagnosis of autism spectrum disorders (ASD) were at increased risk of fever, febrile seizures, or emergency department (ED) visits following measles- or pertussis-containing vaccines compared with children without ASD.MethodsThe study included children born between 1995–2012, aged 4–7 years at vaccination, and members of six healthcare delivery systems within Vaccine Safety Datalink. We conducted self-controlled risk interval analyses comparing rates of outcomes in risk and control intervals within each group defined by ASD status, and then compared outcome rates between children with and without ASD, in risk and control intervals, by estimating difference-in-differences using logistic regressions.ResultsThe study included 14,947 children with ASD and 1,650,041 children without ASD. After measles- or pertussis-containing vaccination, there were no differences in association between children with and without ASD for fever (ratio of rate ratio for measles-containing vaccine = 1.07, 95% CI 0.58–1.96; for pertussis-containing vaccine = 1.16, 95% CI 0.63–2.15) or ED visits (ratio of rate ratio for measles-containing vaccine = 1.11, 95% CI 0.80–1.54; for pertussis-containing vaccine = 0.87, 95% CI 0.59–1.28). Febrile seizures were rare. Pertussis-containing vaccines were associated with small increased risk of febrile seizures in children without ASD.ConclusionChildren with ASD were not at increased risk for fever or ED visits compared with children without ASD following measles- or pertussis-containing vaccines. These results may provide further reassurance that these vaccines are safe for all children, including those with ASD.     

Safety,tolerability, and immunogenicity of 15-valent pneumococcal conjugate vaccine in healthy adults

BackgroundPneumococcal disease remains an important health priority despite successful implementation of pneumococcal conjugate vaccines (PCVs) in infant immunization programs, mainly due to the emergence of diseases caused by serotypes not included in licensed PCVs. A 15-valent pneumococcal conjugate vaccine (PCV-15) containing the 7 serotypes (4, 6B, 9V, 14, 18C, 19F, and 23F) included in licensed PCV-7 available at study initiation plus 8 additional serotypes (1, 3, 5, 6A, 7F, 19A, 22F, 33F) was developed and evaluated in healthy adults 18–45 years of age.MethodsSixty subjects received one dose of PCV-15 or PCV-7. Injection-site and systemic adverse events (AEs) were collected for 14-days postvaccination and serious AEs were collected for 30-days postvaccination. Safety laboratory tests (hematology, chemistry, and urinalysis) were evaluated prior to vaccination and 14-days postvaccination. Serotype-specific IgG and opsonophagocytic killing activity (OPA) responses to 15 serotypes included in PCV-15 were measured immediately prior to vaccination and 30-days postvaccination.ResultsAE incidences were comparable between vaccine groups although numerically higher frequencies of erythema (33.3% versus 13.3%), swelling (50.0% versus 23.3%), and myalgia (63.3% versus 36.7%) were reported among PCV-15 versus PCV-7 recipients. Majority of AEs, irrespective of vaccine received, were transient and of mild-to-moderate intensity. No clinically significant differences were observed when comparing AE duration and severity. No laboratory abnormalities, vaccine-related SAEs or discontinuations from the study due to AEs were reported. IgG concentrations for the shared serotypes substantially increased postvaccination at comparable levels between recipients of PCV-15 and PCV-7. Substantial increases in antibody (IgG and OPA) responses to 8 serotypes unique to PCV-15 were observed in PCV-15 recipients. Slight increases to 2 serotypes unique to PCV-15, serotypes 6A and 19A, were also noted in PCV-7 recipients.ConclusionPCV-15 displays an acceptable safety profile and induces IgG and OPA responses to all serotypes included in the vaccine.     

Cross sectional survey of Varicella-Zoster virus and measles seropositivity in people living with HIV in a Parisian suburb and a review of current immunization guidelines

According to evidence-based guidelines, vaccines against measles and varicella are generally recommended to susceptible HIV-positive patients, as long as they are not severely immunocompromised. However, routine screening to determine serologic status is not recommended. We conducted a seroprevalence study of anti-measles and anti-Varicella-Zoster virus (VZV) antibodies in adults living with HIV (PLWHA) consulting at Avicenne University Hospital in a Parisian suburb. Sera were collected in years 2018–2020 and tested by commercial immunoassays in 268 patients. Most of the patients were born in Sub-Saharan Africa (55 %) and only 23 % in Europe. Measles and varicella seropositivity were present respectively in 91.4 % and 96.2 % of patients. One patient in ten was seronegative to at least one of tested diseases. In the univariate analysis, only younger age (p = 0.027) was associated with a higher risk of measles seronegativity, while shorter time since arrival in France (p < 0.001) and shorter time since HIV discovery (p = 0.007) were associated with a higher risk of VZV seronegativity. In multivariate analysis no association was found. This study highlights the absence of specific risk factors for VZV and measles seronegativity in PLWHA and supports the importance of routine screening, in order to increase immunization rates and reduce risk of complications.     

Vaccinomics: A scoping review

BackgroundThis scoping review summarizes a key aspect of vaccinomics by collating known associations between heterogeneity in human genetics and vaccine immunogenicity and safety.MethodsWe searched PubMed for articles in English using terms covering vaccines routinely recommended to the general US population, their effects, and genetics/genomics. Included studies were controlled and demonstrated statistically significant associations with vaccine immunogenicity or safety. Studies of Pandemrix®, an influenza vaccine previously used in Europe, were also included, due to its widely publicized genetically mediated association with narcolepsy.FindingsOf the 2,300 articles manually screened, 214 were included for data extraction. Six included articles examined genetic influences on vaccine safety; the rest examined vaccine immunogenicity. Hepatitis B vaccine immunogenicity was reported in 92 articles and associated with 277 genetic determinants across 117 genes. Thirty-three articles identified 291 genetic determinants across 118 genes associated with measles vaccine immunogenicity, 22 articles identified 311 genetic determinants across 110 genes associated with rubella vaccine immunogenicity, and 25 articles identified 48 genetic determinants across 34 genes associated with influenza vaccine immunogenicity. Other vaccines had fewer than 10 studies each identifying genetic determinants of their immunogenicity. Genetic associations were reported with 4 adverse events following influenza vaccination (narcolepsy, GBS, GCA/PMR, high temperature) and 2 adverse events following measles vaccination (fever, febrile seizure).ConclusionThis scoping review identified numerous genetic associations with vaccine immunogenicity and several genetic associations with vaccine safety. Most associations were only reported in one study. This illustrates both the potential of and need for investment in vaccinomics. Current research in this field is focused on systems and genetic-based studies designed to identify risk signatures for serious vaccine reactions or diminished vaccine immunogenicity. Such research could bolster our ability to develop safer and more effective vaccines.     

Recurrence risk of a hypotonic hyporesponsive episode in two Australian specialist immunisation clinics

BackgroundA hypotonic hyporesponsive episode (HHE) is a well-described adverse event following immunisation (AEFI) in young children. There is limited data regarding recurrence post re-vaccination.MethodA retrospective analysis of HHEs reported to two tertiary paediatric hospitals in Australia: The Royal Children’s Hospital, Melbourne [2006–11] and the Children’s Hospital Westmead, Sydney [1997–2014].HHE definition level of confidence was allocated according to Brighton Collaboration (BC) criteria and defined immediate if within 30 min post vaccination. The Australian Immunisation Register (AIR) was utilised to document current immunisation status.Results235 HHE cases (135 Melbourne, 100 Sydney) were identified: 47% were female and 67% (157/235) occurred following the routine dose one vaccines at 6–8 weeks of age. Median time following immunisation was 120 min (range 1 min to 14 days) An immediate HHE occurred in 43% (102/235) and by BC criteria, 74% (173/235) were level 1 (definite). Subsequent vaccines were administered under supervision in hospital in 37% overall (86/235); 43% (58/135) in Melbourne and 28% (28/100) in Sydney. HHE recurrence rate was 3% (7/235) [95% confidence interval 1–6%]. AIR records were available in 94% (221/235). At a median age of 3.1 years, 84% (186/221) were up-to-date with recommended vaccines.ConclusionThis study highlights the importance of specialist immunization clinics in supporting the National Immunisation Program, through follow-up and management of serious adverse events following immunization.     

Effectiveness of post-exposure prophylaxis during varicella outbreaks among primary and middle school students in Shanghai: An analysis of three-year surveillance data

ObjectivesTo evaluate the effectiveness of post-exposure prophylaxis conducted during varicella outbreaks among students in Shanghai.MethodsSurveillance data were collected from September 1, 2013 to December 31, 2016 involving 3524 susceptible students in 109 primary and middle school classes where emergency vaccinations (EVs) had been administered. Students were divided into two groups according to their prior vaccination (PV) varicella vaccine status. A secondary attack rate was used to compare EV and non-EV groups using a chi-squared test. Stratification analyses were performed, adjusting for the EV administration date, the vaccination coverage rate, and the number of cases prior to the EV.ResultsThe effectiveness rate was 92.2% (95% confidence interval (CI): 37.1–99.0%) when EV was applied within 3 days following the outbreak onset date, and 95.2% (95% CI: 79.9–98.8%) when vaccination coverage was ≥80% among students with PV. When students with PV received an EV for varicella within 3 days, the effectiveness rate was 100%.ConclusionsEV showed high protective effectiveness for varicella during outbreaks, especially if administered within 3 days of an outbreak and in conjunction with a high coverage rate.