Ross Andrews, Australia

Menzies School of Health Research Child Health Division

Author Of 4 Presentations

BREAKTHROUGH IPD FOLLOWING 13VPCV SCHEDULE CHANGE FROM 3+0 TO 2+1 AMONG AUSTRALIAN CHILDREN (ID 921)

Session Name
Population Sciences - Epidemiology, Economics, and Mathematical Modelling

Abstract

Background

In mid-2018, the Australian infant 13vPCV schedule changed from three primary doses (3+0) to two primary doses and a 12 month booster (2+1) to address increasing breakthrough cases of invasive pneumococcal disease (IPD), predominantly in children >12 months. We assess the impact of this schedule change on breakthrough IPD.

Methods

All cases of breakthrough IPD following 13vPCV (2012-2018) reported to the national notifiable diseases surveillance system were analysed by age, serotype and clinical syndrome. In addition, cases in the first 3 quarters post-schedule change were compared to corresponding period pre-change.

Results

Annual 13vPCV breakthrough case counts in children aged <5yrs (figure) increased progressively from 2012(n=3) to 2017(n=73) but declined in 2018 (n=65). Of 306 total cases, 297 were caused by serotypes 3(41%),19A(38%) and 19F(19%). Those aged 12-24 months accounted for 41% (n=125) of cases. Over two thirds of cases (n=211) were pneumonia and 12 were meningitis. Breakthrough cases in children aged >12 months post-schedule change were still more than that in the comparison pre-change period (41 versus 31).

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Conclusions

The change to administer the third scheduled PCV dose as a booster (2+1)is expected to reduce breakthrough IPD by improving both direct and indirect protection from 13vPCV but discernible impact is not yet observed.

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INTERCHANGEABILITY OF PHID-CV10 AND PCV13 IN PRIMARY COURSE SCHEDULES (ID 204)

Abstract

Background

In remote communities of northern Australia, we previously demonstrated that the onset of otitis media (OM) in Aboriginal infants was preceded by acquisition of bacterial pathogens that colonise the nasopharynx (NP) soon after birth. We aimed to determine safety and effectiveness of mixed vaccine schedules against early infection due to non-typeable Haemophilus influenzae and Streptococcus pneumoniae.

Methods

In an open-label controlled trial, we randomised (1:1:1) Aboriginal infants at 28 to 38 days of age, to either Prevenar13™ (P, PCV13) at 2-4-6 months of age (_PPP), Synflorix™ (S, PHiD-CV10) at 2-4-6 months (_SSS), or Synflorix at 1-2-4 months plus Prevenar13 at 6 months (SSSP). Primary outcomes (assessor-blinded) were immunogenicity at 7 months of age against pneumococcal serotypes 3, 6A, and 19A, and protein D (GMCs and proportions of infants with IgG > 0·35 µg/mL or > 100 EL.U/mL, respectively). Secondary immunogenicity outcomes at 2 and 4 months are also reported.

Results

A 4-dose early 1-2-4-6 month combination schedule of Synflorix plus Prevenar13 (SSSP) provided superior overall immune protection against serotypes 3, 6A, 19A, and protein D, compared to standard 3-dose 2-4-6 month schedules (_SSS or _PPP).

Conclusions

These vaccines can be combined safely and effectively within this primary schedule, with no evidence of immune suppression.

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SUBSTANTIAL INDIRECT PROTECTION AGAINST IPD AND PNEUMONIA HOSPITALISATIONS AT LOW LEVELS OF VACCINE COVERAGE IN AUSTRALIA, YET HIGH COVERAGE REQUIRED FOR NEAR-ELIMINATION (ID 854)

HEAD TO HEAD COMPARISONS AT 2, 4, AND 7 MONTHS, FOLLOWING STANDARD AND COMBINED PHID-CV10 AND PCV13 SCHEDULES. (ID 429)

Abstract

Background

Australian Aboriginal children are at high risk of early infection withStreptococcus pneumoniae and non-typeable Haemophilus influenzae (NTHi). We evaluated immunogenicity against 10 shared serotypes of a 4-dose combination schedule of PHiD-CV10 at 1-2-4 months plus PCV13 at 6 months, compared with standard 2-4-6 month schedules.

Methods

Infants were allocated (1:1:1) at 28 to 38 days of age, to 3-dose schedules of PCV13 (P) or PHiD-CV10 (S) at 2-4-6 months (_PPP or _SSS), or a combination schedule at 1-2-4-6 months (SSSP). Immunogenicity was measured at 2, 4, and 7 months.

Results

At 2 months the SSSP combination was superior to pre-vaccination (VTs other than 6B, 19F, or 23F). At 4 months SSSP was superior to _PPP (9 VTs) and _SSS (7 VTs), and _SSS was superior to _PPP (8 VTs). At 7 months, SSSP was superior to _PPP (1, 6B, 9V, 19F and 23F) and _SSS (8 VTs), and _PPP was superior to _SSS (8 VTs). OPA supports the SSSP schedule, particularly against 1, 6B, and 23F.

Conclusions

The 1-2-4-6 month schedule (SSSP) was superior at 2, 4, and 7 months of age compared to _SSS or _PPP, particularly for 1, 6B, and 23F at 7 months. At 4 months, _SSS was superior to _PPP.

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