Robert Menzies

Reduction in Hospitalizations for Pneumonia Associated With the Introduction of a Pneumococcal Conjugate Vaccination Schedule Without a Booster Dose in Australia

Background: Postmarketing surveillance of heptavalent pneumococcal conjugate vaccine (7vPCV) has shown significant reductions in admissions coded as pneumonia in countries where a booster dose is given in the second year of life. In Australia, a 3-dose primary schedule at 2, 4, and 6 months of age without a booster has been funded nationally for non-Indigenous children since 2005. Methods: All hospital discharges in Australia with the primary diagnosis coded as pneumonia between July 1998 and June 2007 were identified from a national electronic database. Monthly rates of hospitalization for pneumonia over this period were determined for the age groups <2, 2–4, 5–17, 18–39, 40–64, and ≥65 years. Negative binomial regression modeling, adjusting for background and seasonal trends, was used to quantify the effect of the 7vPCV program. Results: A total of 523,591 eligible hospital discharges were identified. In the 30 months following 7vPCV introduction, there were significant adjusted reductions in all-cause pneumonia in children aged <2 and 2 to 4 years of 38% (95% CI = 36%–40%), and 29% (26%–31%), respectively. Reductions of between 3% and 11% were observed in the older age groups. Interpretation: The significant differential effects observed are strongly suggestive of the PCV7 program being responsible for the observed reduction in pneumonia hospitalizations in Australia, and the magnitude was comparable to that documented in countries with a booster dose. This finding appears robust and may be related to high levels of vaccination coverage and catch-up early in the program, or to relatively lower levels of serotype replacement without a booster dose.

The effects of a converting enzyme inhibitor (Captopril) and angiotensin II on fetal renal function

1 Renal function was studied in chronically catheterized fetal sheep (119–128 days gestation), before and during treatment of the ewe with the angiotensin converting enzyme (ACE) inhibitor, Captopril, which crosses the placenta and blocks the fetal renin angiotensin system. 2 An i.v. dose of 15 mg (about 319 μg kg−1) of Captopril to salt‐replete ewes followed by an infusion to the ewe of 6 mg h−1 (about 128 μg kg−1 h−1) caused a fall in fetal arterial pressure (P < 0.01), and a rise in fetal renal blood flow (RBF) from 67.9 ± 5.6 to 84.9 ± 8.3 ml min−1 (mean ± s.e.mean) (P < 0.05). Renal vascular resistance and glomerular filtration rate (GFR) fell (P < 0.01); fetal urine flow (P < 0.01) and sodium excretion declined (P < 0.05). 3 Ewes were treated for the next 2 days with 15 mg Captopril twice daily. On the 4th day, 15 mg was given to the ewe and fetal renal function studied for 2 h during the infusion of Captopril (6 mg h−1) to the ewe. Of the 9 surviving fetuses, 3 were anuric and 3 had low urine flow rates. When 6 μg kg−1 h−1 of angiotensin II was infused directly into the fetus RBF fell from 69 ± 10.1 ml min−1 to 31 ± 13.9 ml min−1, GFR rose (P < 0.05) and urine flow (P < 0.01) and sodium excretion increased in all fetuses. 4 It is concluded that the small fall in fetal arterial pressure partly contributed to the fall in fetal GFR but in addition, efferent arteriolar tone fell so that the filtration pressure fell further. Thus maintenance of fetal renal function depends on the integrity of the fetal renin angiotensin system. These findings explain why use of ACE inhibitors in human pregnancy is associated with neonatal anuria.

The Association of Respiratory Viruses, Temperature, and Other Climatic Parameters with the Incidence of Invasive Pneumococcal Disease in Sydney, Australia

BACKGROUND Increases in incidence of invasive pneumococcal disease (IPD) during the colder months of the year in temperate regions are well recognized, but few detailed studies of possible interactions are available. We examined the relationship between virus activity, climatic parameters, and IPD during a winter in which there were separate peak incidences of influenza and respiratory syncytial virus (RSV) infection. METHODS We performed an ecological study that correlated population-based data on IPD and respiratory virus activity in the year 2000 in metropolitan New South Wales, Australia, with climatic parameters, including weekly mean maximum and minimum temperature, relative humidity, rainfall, and wind speed. RESULTS In children, RSV activity was significantly positively correlated with IPD activity (r = 0.578; P = .002) but not with influenza virus activity. There was a weak inverse relationship between parainfluenza virus activity and IPD activity (r = -0.401; P = .043) and a stronger inverse relationship between weekly mean maximum temperature (r = -0.458; P = .001), weekly mean minimum temperature (r = -0.437; P = .001), and IPD activity. In adults, there was no significant correlation between RSV or influenza virus activity alone and IPD, but the combination of RSV and influenza was significantly correlated with IPD (r = 0.481; P = .013). CONCLUSIONS This study suggests that RSV infection and influenza contribute to IPD incidence peaks differently for children than for adults. Data from other geographic areas and more rigorous study designs are required to confirm these findings.

Changes in hospitalisations for acute gastroenteritis in Australia after the national rotavirus vaccination program.

Objective: To evaluate the impact of the Australian rotavirus vaccination program on both rotavirus and all‐cause acute gastroenteritis (AGE) hospitalisations and to compare outcomes in Indigenous and non‐Indigenous people.

Fall in Genital Warts Diagnoses in the General and Indigenous Australian Population Following Implementation of a National Human Papillomavirus Vaccination Program: Analysis of Routinely Collected National Hospital Data

BACKGROUND Human papillomavirus (HPV) vaccination targeting females aged 12-13 years commenced in Australia in 2007, with catch-up vaccination of females aged 13-26 years continuing to 2009. Whole-population analyses, including effects on the Indigenous population, have not previously been reported. METHODS All hospital admissions between 1999-2011 involving a diagnosis of genital warts were obtained from a comprehensive national database. We compared the age-specific rates before to those after implementation of the vaccination program, according to sex and other characteristics. RESULTS Admission rates decreased from mid-2007 in females aged 12-17 years (annual decline, 44.1% [95% confidence interval {CI}, 35.4%-51.6%]) and from mid-2008 in females and males aged 18-26 years (annual declines, 31.8% [95% CI, 28.4%-35.2%] and 14.0% [95% CI, 5.1%-22.1%], respectively). The overall reductions from 2006-2007 to 2010-2011 were 89.9% (95% CI, 84.4%-93.4%) for females aged 12-17 years, 72.7% (95% CI, 67.0%-77.5%) for females aged 18-26 years, and 38.3% (95% CI, 27.7%-47.2%) for males aged 18-26 years. Compared with the average annual number before program implementation, about 1000 fewer hospital admissions involved a warts diagnosis during 2010-2011. Reductions after program implementation were similar for Indigenous (86.7% [95% CI, 76.0-92.7]) and non-Indigenous (76.1% [95% CI, 71.6%-79.9%]) females aged 15-24 years (P(heterogeneity) = .08). CONCLUSIONS National population-based hospital data confirm previous clinic-based reports of a marked decline in genital warts diagnoses among young people in Australia after program implementation, including indirect benefits to males. The impact of HPV vaccination appears to be similar in young Indigenous and non-Indigenous females.

The impact of pneumococcal conjugate vaccine on rates of myringotomy with ventilation tube insertion in Australia.

Background: In randomized controlled trials and postmarketing studies the heptavalent pneumococcal conjugate vaccine (7vPCV) has been shown to reduce myringotomy with ventilation tube insertion (MVTI) procedures in a 4-dose schedule. In Australia, a 3-dose schedule at 2, 4, and 6 months of age is routinely used in non-Indigenous children. Our aim was to determine if a reduction in MVTI comparable to that documented in the United States occurred in Australia despite the absence of the booster dose. Methods: All episodes of MVTI in Australia from July 1998 to June 2007 among children aged ≤9 years were identified in an electronic database of national hospitalization records, including the public and private sectors. Age-stratified rates of MVTI before and after introduction of 7vPCV into the national immunization program in 2005 were determined, with Poisson regression modeling used to determine the vaccine impact after adjusting for background and seasonal trends. Results: A total of 238,634 hospital separations were identified. In the 2.5 years after routine 7vPCV introduction, there was a significant adjusted reduction in MVTI in children aged <1, 1, and 2 years of 23%, 16%, and 6%, respectively. A nonsignificant reduction was observed in those aged 3 and 4 years, while a significant increase of 5% was observed for the 5- to 9-year age group. Conclusions: Although ecologic data such as this have limitations, the significant differential effects observed by time period and age group are suggestive of a vaccine effect of similar magnitude to that documented by postmarketing surveillance in the United States. The rapid uptake of 7vPCV in Australia, including catch up to 2 years of age, is an important difference to the United States and it is possible that an even greater effect would have been observed with a booster dose in the second year of life. Longer term data will be needed to fully assess the role of a booster dose.

Epiglottitis in Sydney before and after the introduction of vaccination against Haemophilus influenzae type b disease

Abstract

School-based vaccination in NSW.

Over the past decade the number of recommended and funded vaccines for adolescents has increased, becoming a substantial part of the National Immunisation Program in Australia. In response, NSW has implemented disease-specific vaccination campaigns for both children and adolescents and more recently established a routine high school-based vaccination program to administer vaccines to this often hard to reach group. This paper outlines the history of school-based vaccination in NSW from its commencement in 1971 to coverage from early disease-specific programs, and describes the implementation of the current program of routine vaccination. Substantial coverage has been achieved across the age spectrum 5-17 years, highlighting the effectiveness of the school-based vaccination program in reaching large numbers of adolescents.

Impact of the introduction of rotavirus vaccine on the timeliness of other scheduled vaccines: The Australian experience ☆

Strict age limits for receipt of rotavirus vaccines and simultaneous use of vaccines requiring two (Rotarix(®)) and three (RotaTeq(®)) doses in Australia may impact on coverage and timeliness of other vaccines in the infant schedule. Using data from the Australian Childhood Immunisation Register (ACIR), coverage and timeliness of rotavirus vaccines and changes in timeliness of other infant vaccines following rotavirus vaccine introduction was examined, with particular emphasis on Indigenous infants in whom coverage is less optimal. Final dose rotavirus coverage reached 83% within 21 months of program commencement but remained 7% lower than other vaccines due in infancy. Coverage was 11-17% lower in Indigenous infants. Adherence to the first dose upper age limits for rotavirus vaccine was high with >97% of children vaccinated by the recommended age, but for subsequent rotavirus doses, receipt beyond the upper age limits was more common, especially in Indigenous children. Following rotavirus vaccine introduction, there were improvements in timeliness of receipt of all doses of DTPa-containing and 7-valent pneumococcal conjugate vaccines. High population coverage can be attained with rotavirus vaccines, even with adherence to strict upper age restrictions for vaccine dose administration. Rotavirus vaccine introduction appears to have impacted upon the timeliness of other concomitantly scheduled vaccines. These factors should be considered when rotavirus programs are introduced.

Long-term Impact of a “3 + 0” Schedule for 7- and 13-Valent Pneumococcal Conjugate Vaccines on Invasive Pneumococcal Disease in Australia, 2002–2014

Background. Australia introduced universal 7-valent pneumococcal conjugate vaccine (PCV7) from 2005, replaced by 13-valent PCV (PCV13) in 2011, uniquely among high-income countries giving doses at 2, 4, and 6 months (3 + 0 schedule). Data on impact of a timely 3 + 0 PCV schedule with high coverage are sparse, with none for PCV13. Methods. We used national surveillance of invasive pneumococcal disease (IPD) from 2002 for baseline and appropriate later comparison periods to calculate incidence rate ratios (IRRs) by serotype and age using a Poisson model. PCV coverage was assessed from the Australian Childhood Immunisation Register. Results. After 9 years of timely 3-dose PCV coverage of >92%, all-age IPD in Australia almost halved (IRR, 0.53; 95% confidence interval [CI], .50–.57), but differed by PCV era. Reductions in IPD due to vaccine serotypes from PCV7 (IRR, 0.20; CI, .17–.22) were about 2-fold greater than for IPD due to extra serotypes in PCV13 (13v-non7v) in a similar period (IRR, 0.58; CI, .51–.66). Post-PCV13 declines in serotype 19A IPD in persons aged <2 years (IRR, 0.23; CI, .13–.35) and ≥2 years (IRR, 0.35; CI, .28–.44) differed from other 13v-non7v IPD (IRR, 0.73; CI, .35–1.48 for those aged <2 years and IRR, 0.96; CI, .81–1.15 for those ≥2 years). Meningitis due to vaccine serotypes nearly disappeared in children eligible for 3 PCV13 doses. IPD due to non-PCV13 serotypes increased by 30% compared with 76% for non-PCV7 serotypes in equivalent period of vaccine use. Conclusions. Reductions in vaccine-type IPD post-PCV13 were inferior to Australian experience with PCV7 and reports from high-income countries giving a PCV booster dose. Applicability of findings to other settings would depend on age of IPD onset, serotype profile, and timeliness of vaccination.