Timeliness of routine immunization in non-preterm children less than 2 years old using electronic data capture in an ambulatory setting in France in the context of vaccine hesitancy

Non-immunization associated with increased risk of sudden unexpected death in infancy: A national case-control study

OBJECTIVE

In the context of vaccine scepticism, our study aimed to analyse the association between immunization status and the occurrence of sudden unexpected death in infancy (SUDI).

STUDY DESIGN

A multi-centre case-control study was conducted between May 2015 and June 2017 with data from the French national SUDI registry (OMIN) for 35 French regional SUDI centres. Cases were infants under age 1 year who died from SUDI and who were registered in OMIN. Controls, matched to cases by age and sex at a 2:1 ratio, were infants admitted to Nantes University Hospital. All immunization data for diphtheria (D), tetanus (T), acellular pertussis (aP), inactivated poliovirus (IPV), Haemophilus influenzae b (Hib), hepatitis B (HB) and 13-valent pneumococcal conjugate vaccine (PCV13) were collected by a physician. Cases and controls were considered immunized if at least one dose of vaccine was administered.

RESULTS

A total of 91 cases and 182 controls were included. The median age was 131 days (interquartile range 98-200.0) and the sex ratio (M/F) was about 1.1. For all vaccines combined (D-T-aP-IPV-Hib and PCV13), 22 % of SUDI cases versus 12 % of controls were non-immunized, which was significantly associated with SUDI after adjustment for potential adjustment factors (adjusted odds ratio 2.01 [95 % confidence interval 1.01-3.98, p = 0,047]).

CONCLUSIONS

Non-immunization for D-T-aP-IPV-Hib-HB and PCV13 was associated with increased risk of SUDI. This result can be used to inform the general public and health professionals about this risk of SUDI in case of vaccine hesitancy.

Effect of change in vaccine schedule on pertussis epidemiology in France: a modelling and serological study

BACKGROUND

In April-May, 2013, France modified its pertussis vaccination schedule, which uses the acellular pertussis vaccine, from three primary doses at 2, 3, and 4 months of age and a first booster at 16-18 months of age (former schedule) to two primary doses at 2 and 4 months of age and a first booster at 11 months of age (new schedule). We aimed to assess the subsequent effect of the vaccine schedule change on pertussis epidemiology in France.

METHODS

In this modelling study, using data collected between Jan 1, 2012, and Dec 31, 2019, from French national surveillance sources, we analysed the PCR test results of nasopharyngeal swabs collected from symptomatic outpatients aged 2-20 years with suspected pertussis. We developed a negative binomial regression model for the number of confirmed pertussis cases by year and age to assess the relative risks of pertussis depending on vaccine schedule. The linear predictor included the year, the age group, the population size, and a proxy of waning immunity. We tested different models in which waning immunity could vary with vaccine schedule and type of primary vaccine. The models were fitted to the 2012-18 data via Bayesian Markov chain Monte Carlo sampling, and the 2019 data were left out for external model validation. We also compared the anti-pertussis toxin (PT) antibody concentrations in leftover sera from children not tested for pertussis or recent respiratory tract infection aged 2-5 years born before and after the vaccine schedule change.

FINDINGS

We collected data on 7493 confirmed cases of pertussis. The model that best fitted the 2012-18 epidemiological data supported a faster waning of immunity following vaccination with the new vaccine schedule. 3 years after vaccination, the risk of developing pertussis was 1·7 (95% CI 1·4-2·0) times higher for children vaccinated according to the new schedule than those vaccinated according to the former schedule. The model correctly predicted the age distribution of cases in 2019. Geometric mean concentrations (GMC) of anti-PT IgG were 50% lower in children aged 2 years vaccinated with the new schedule (GMC=5·85 IU/mL [95% CI 4·08-8·39]) than in children of the same age vaccinated with the former schedule (GMC=11·62 IU/mL [95% CI 9·05-14·92]; p=0·0016), and 43% lower in children aged 3 years vaccinated with the new schedule (GMC=3·88 IU/mL [95% CI 2·82-5·34]) than those with the former schedule (GMC=6·80 IU/mL [95% CI 4·77-9·70]; p=0·026).

INTERPRETATION

A shorter-lived protection induced by the new vaccine schedule recommended in France since 2013 is associated with an increase of pertussis cases in children aged 2-5 years. If similar findings are observed in other countries and clinical trials, these findings should be considered in future pertussis vaccination policies.

FUNDING

INCEPTION, Labex-IBEID, Institut Pasteur, and Santé Publique France.

Adherence to the paediatric immunisation schedule in England

Both adequate coverage and adherence to paediatric immunisation schedules are required for optimal protection against vaccine preventable diseases. We studied the timeliness of routine paediatric vaccinations according to the NHS’s immunisation schedule and potential factors of schedule adherence. Immunisation data was obtained from the Royal College of General Practitioners (RCGP) Research and Surveillance Centre (RSC). We collected vaccine types, doses, and dates for all routine paediatric vaccines between 2008 and 2018: DTaP/IPV/Hib/HepB, DTaP/IPV/Hib, DTaP/IPV, dTaP/IPV, Td/IPV, MMR, PCV, MenB, MenC, MenACWY, Hib/MenC, RV, HPV. Adherence to the immunisation schedule was calculated for each vaccine and dose. Differences in adherence between genders, NHS regions, and IMD quintiles were analysed. Our study included 6′257′828 vaccinations in 1′005′827 children. Seventy-five percent of first doses were administered within one (for vaccines scheduled in the first year of life) or two months (for vaccines scheduled later in life) following the recommended age, 19% too late and 6% too early. About half of the subsequent doses were given timely. The time between first and second doses was too short for 36% of vaccinations while 13% of second doses were administered too long after the first dose. Third doses were administered timely for 45%, too short for 37%, and too long for 18% of vaccinations. Differences in immunisation schedule adherence between girls and boys were negligible, except for HPV, and differences between the four main NHS regions were small. Overall, immunisation schedule adherence improved slightly with decreasing deprivation according to the Index of Multiple Deprivation. Efforts are required to improve the timeliness of paediatric vaccinations and to assure adequate protection against vaccine preventable diseases. We propose developing a compound measure combining coverage and adherence to provide a better indication of the protection against vaccine preventable diseases in a community.

New Approach to the Surveillance of Pediatric Infectious Diseases From Ambulatory Pediatricians in the Digital Era

BACKGROUND

Many ambulatory networks in several countries have established syndromic surveillance systems to detect outbreaks of different illnesses. Here, we describe a new Pediatric and Ambulatory Research in Infectious diseases network that combined automated data extraction from the computers of primary care pediatricians.

METHODS

Pediatricians who used the same software, AxiSanté 5-Infansoft for electronic medical records were specially trained in infectious diseases, encouraged to comply with French treatments' recommendations, use of point-of-care tests and vaccination guidelines. Infectious disease diagnoses in children <16 years old in the records triggered automatic data extraction of complete records. A quality control process and external validation were developed.

RESULTS

From September 2017 to February 2020, 107 pediatricians enrolled 57,806 children (mean age 2.9 ± 2.6 years at diagnosis) with at least one infectious disease diagnosis among those followed by the network. Among the 118,193 diagnoses, the most frequent were acute otitis media (n = 44,924, 38.0%), tonsillopharyngitis (n = 13,334, 11.3%), gastroenteritis (n = 12,367, 10.5%), influenza (n = 11,062, 9.4%), bronchiolitis (n = 10,531, 8.9%), enteroviral infections (n = 8474, 7.2%) and chickenpox (n = 6857, 5.8%). A rapid diagnostic test was performed in 84.7% of cases of tonsillopharyngitis and was positive in 44%. The antibiotic recommendations from French guidelines were strictly followed: amoxicillin was the most prescribed antibiotic and less than 10% of presumed viral infections were treated.

CONCLUSIONS

This "tailor-made" network set up with quality controls and external validation represents a new approach to the surveillance of pediatric infectious diseases in the digital era and could highly optimize pediatric practices.

Evaluation of measles vaccination coverage in Lincang City, Yunnan Province, China

Background: Lincang City in Yunnan Province on the China-Myanmar border, has reached the World Health Organization recommended coverage (95%) for measles-containing vaccine (MCV), but measles outbreaks still occur. We conducted a survey in Lincang City to determine the measles vaccination status of children on the China-Myanmar border.Methods: We used multistage sampling among children aged 8-83 months. Information on measles vaccination status was obtained from the child's vaccination certificate, and serum samples were tested using commercially available ELISA kits.Results: A total of 938 children were surveyed. The vaccination coverage rate was 98.9% (95% CI: 98.2-99.6%) for measles-containing vaccine dose 1 (MCV1), and 95.8% (95% CI:94.9-96.7%) for measles-containing vaccine dose 2 (MCV2). The timely vaccination coverage rate was 52.0% (95% CI:48.8-55.2%) for MCV1, and 74.1% (95% CI: 82.9-89.0%) for MCV2. The timely-and-complete vaccination coverage rate was 41.0% (95% CI: 36.7-45.3%). The median delay period was 33 (95% CI: 27-39) days for MCV1, and 196 (95% CI: 146-246) days for MCV2. The seropositivity rate in children aged less than 7 years was 94.0% (95% CI: 92.5-95.5%) with a geometric mean titer of 1210.1 mIU/mL.Conclusions: The MCV coverage was high, but timely and timely-and-complete vaccination coverage were low and insufficient to prevent measles outbreaks. It is necessary to add the timely and timely-and-complete vaccination coverage as indicators of vaccination to provide a more complete picture of measles immunization status.

Trends in pediatric hospitalizations for ambulatory care sensitive respiratory diseases in Brazil

OBJECTIVE

To analyze the trend in hospitalization rates for ambulatory care sensitive respiratory diseases (ACSRD) of children under five years of age in Brazil.

DESIGN

Time series study of hospitalization rates using secondary information from the Hospital Information System of the Brazil's Unified Health System.

SAMPLE

Hospitalizations of children under five years of age living in Brazilian regions. Hospitalizations were separated according to cause: nose and throat infections, asthma, bacterial pneumonias, and lung diseases.

MEASUREMENTS

Rates were calculated for total hospitalizations for ACSRD, and by cause, age group, and region. Trends were analyzed by using means of simple linear regression and were classified into stationary (p ≥ .05), ascending (β positive and p < .05) or declining (β negative and p < .05) trends.

RESULTS

All regions showed stationary trends in total hospitalization rates for ACSRDs, except in the Southeast, where trends were ascending. Asthma was the only cause that showed a declining trend. Bacterial pneumonias showed stationary trends, while lung diseases and nose and throat infections had predominantly ascending trends.

CONCLUSION

Brazil's hospitalization rates for ACSRDs are high. Investigations into primary health care organization and work processes, as well as socioeconomic, cultural, and geographical factors are necessary.

Timeliness and equity of infant pertussis vaccination in wales: Analysis of the three dose primary course

Infants aged under one year are at the highest risk of severe complications or death from pertussis infection. Prompt vaccination with a three dose course at two, three and four months of age decreases the amount of time they are vulnerable following waning of maternal antibodies. In Wales, uptake of all three doses of the primary course of pertussis containing vaccine is high. However, timeliness and equity at a population level have not been previously reported. This analysis included 163,733 children born from 1st January 2013 to 31st December 2017. In this cohort 87.9% received the first dose of a pertussis containing vaccine by 12 weeks of age, 87.1% had received all three doses by 24 weeks of age, and 96.3% received three doses by 52 weeks of age. Differences in uptake between those living in the most deprived and least deprived quintiles of Lower Super Output Area (LSOA) were smaller than differences in timeliness, but statistically significant. In 2017 the difference in timely uptake between those living in the most and least deprived quintiles was 4%, 5% and 7% for doses one, two and three respectively. There was a difference of 10% in the proportion of infants receiving all three primary vaccinations on time between the most and least deprived quintile of LSOAs. Consideration is needed on interventions that will help improve timeliness such as enhanced follow up of defaulters, electronic communication between primary care data systems, enhanced health visitor intervention and opportunistic vaccination in those who fail to attend scheduled vaccination appointments. There is also the need for routine monitoring of timeliness and further research into what influences delayed vaccination.