TY - JOUR
T1 - Pertussis Disease and Antenatal Vaccine Effectiveness in Australian Children
AU - Quinn, Helen E.
AU - Comeau, Jeannette L.
AU - Marshall, Helen S.
AU - Elliott, Elizabeth J.
AU - Crawford, Nigel W.
AU - Blyth, Christopher C.
AU - Kynaston, Jennifer A.
AU - Snelling, Tom L.
AU - Richmond, Peter C.
AU - Francis, Joshua R.
AU - Macartney, Kristine K.
AU - McIntyre, Peter B.
AU - Wood, Nicholas J.
N1 - Funding Information:
This work was supported by an NHMRC partnership project [1113851], with contributions from the Australian Government Department of Health, and the state health departments of New South Wales, Victoria, Western Australia, South Australia, Queensland and the Northern Territory. H.S.M. receives support from an NHMRC Practitioner Fellowship (2019–2023), E.J.E. received support from an NHMRC Practitioner Fellowship (2012–2016) and a Medical Research Futures Fund Next Generation Fellowship (2018–2022), T.L.S. receives support from an NHMRC Career Development Fellowship (2016–2020), and N.J.W. receives support from an NHMRC Career Development Fellowship (2017–2021).
PY - 2022/3/1
Y1 - 2022/3/1
N2 - BACKGROUND: Population-level studies of severe pertussis extending beyond infancy are sparse, and none in the context of antenatal vaccination. We compared hospitalized pertussis cases from birth to 15 years of age before and after introduction of antenatal immunization. METHODS: Active surveillance of laboratory-confirmed pertussis hospitalizations in a national network of pediatric hospitals in Australia January 2012 to June 2019. Impact of maternal vaccination was assessed by vaccine effectiveness (VE) in cases and test-negative controls with <2 months of age and by before-after comparison of age distribution of cases. Among cases eligible for one or more vaccine doses, we examined proportions age-appropriately immunized and with comorbidities by age group. RESULTS: Among 419 eligible cases, the proportion <2 months of age significantly decreased from 33.1% in 2012 to 2014 compared with 19.6% in 2016 to 2019 when mothers of only 4 of 17 (23.5%) cases <2 months of age had received antenatal vaccination. VE was estimated to be 84.3% (95% CI, 26.1-96.7). Across all years (2012-2019), of 55 cases 4-11 months of age, 21 (38%) had ≥2 vaccine doses, whereas among 155 cases ≥12 months of age, 122 (85.2%) had ≥3 vaccine doses. Prevalence of comorbidities (primarily cardiorespiratory) increased from 5 (2.1%) <6 months of age to 36 (24.2%) ≥12 months of age (P < 0.001), with 6/16 (38%) cases ≥12 months of age who required intensive care having comorbidities. CONCLUSIONS: Below the age of 12 months, prevention of severe pertussis will be maximized by high maternal antenatal vaccine uptake and timeliness of infant vaccine doses. Despite full immunization, we found children ≥12 months of age accounted for 27% of hospitalizations <15 years, with 24% having comorbities, suggesting new vaccine strategies, such as additional doses or more immunogenic vaccines, require evaluation.
AB - BACKGROUND: Population-level studies of severe pertussis extending beyond infancy are sparse, and none in the context of antenatal vaccination. We compared hospitalized pertussis cases from birth to 15 years of age before and after introduction of antenatal immunization. METHODS: Active surveillance of laboratory-confirmed pertussis hospitalizations in a national network of pediatric hospitals in Australia January 2012 to June 2019. Impact of maternal vaccination was assessed by vaccine effectiveness (VE) in cases and test-negative controls with <2 months of age and by before-after comparison of age distribution of cases. Among cases eligible for one or more vaccine doses, we examined proportions age-appropriately immunized and with comorbidities by age group. RESULTS: Among 419 eligible cases, the proportion <2 months of age significantly decreased from 33.1% in 2012 to 2014 compared with 19.6% in 2016 to 2019 when mothers of only 4 of 17 (23.5%) cases <2 months of age had received antenatal vaccination. VE was estimated to be 84.3% (95% CI, 26.1-96.7). Across all years (2012-2019), of 55 cases 4-11 months of age, 21 (38%) had ≥2 vaccine doses, whereas among 155 cases ≥12 months of age, 122 (85.2%) had ≥3 vaccine doses. Prevalence of comorbidities (primarily cardiorespiratory) increased from 5 (2.1%) <6 months of age to 36 (24.2%) ≥12 months of age (P < 0.001), with 6/16 (38%) cases ≥12 months of age who required intensive care having comorbidities. CONCLUSIONS: Below the age of 12 months, prevention of severe pertussis will be maximized by high maternal antenatal vaccine uptake and timeliness of infant vaccine doses. Despite full immunization, we found children ≥12 months of age accounted for 27% of hospitalizations <15 years, with 24% having comorbities, suggesting new vaccine strategies, such as additional doses or more immunogenic vaccines, require evaluation.
KW - vaccine
KW - immunization
KW - pertussis
KW - surveillance
KW - effectiveness
UR - http://www.scopus.com/inward/record.url?scp=85124497695&partnerID=8YFLogxK
U2 - 10.1097/INF.0000000000003367
DO - 10.1097/INF.0000000000003367
M3 - Article
C2 - 34711785
AN - SCOPUS:85124497695
VL - 41
SP - 180
EP - 185
JO - Pediatric Infectious Disease Journal
JF - Pediatric Infectious Disease Journal
SN - 0891-3668
IS - 3
ER -