Response to Wu et al. — Cost-effectiveness analysis of infant pneumococcal vaccination in Malaysia and Hong Kong

Abstract

A recently published paper that assessed the comparative cost-effectiveness of the 2 pneumococcal conjugate vaccines (PCVs) in Malaysia and Hong Kong reported that the 13-valent PCV vaccine (PCV13) is a better choice compared to the 10-valent pneumococcal non-typeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV or PCV10) from both a payer and societal perspective as well as under various scenarios. However, the analysis relied on a large number of assumptions that were either erroneous or did not take into account the most recent body of evidence available. A rigorous evaluation of the underlying assumptions is necessary to present a fair and balanced analysis for decision-making.

Cost-effectiveness analysis of a universal mass vaccination program with a PHiD-CV 2+1 schedule in Malaysia

“…Unlike Aljunid et al [ 10 ], Wu et al [ 11 ] did not account for the protective effects of PHiD-CV in a number of key areas: (1) cross-protection against serotypes 6A and 19A, which has been demonstrated in a number of recent studies [ 12 – 14 ]; (2) indirect (herd) protection against IPD, which has been shown in surveillance data from Finland [ 15 ] and New Zealand [ 16 ]; and (3) protection against NTHi AOM, which has been shown in both the randomized controlled Clinical Otitis Media and Pneumonia Study (COMPAS) study [ 17 ] and the randomized controlled Pneumococcal Otitis Efficacy Trial (POET) study of PHiD-CV’s 11-valent precursor [ 18 ]. Wu et al’s [ 11 ] methodology has recently been critiqued by Varghese et al [ 19 ]. Excluding the protective effects of PHiD-CV in these key areas is against the current evidence and could have had a significant impact on the cost-effectiveness of PHiD-CV versus PCV13.…”

Letter to the editor to: Isturiz et al. Streptococcus pneumoniae serotype 19A: worldwide epidemiology. Expert review of vaccines 2017;16(10):1007-27

“…In summary, there is similar evidence of direct protection against serotype 19A for both vaccines in children [2,12], although herd effects in older ages appear more variable. There is evidence of reduction of serotype 19A carriage from a randomized controlled trial [32] and evidence of long-term protection and anamnestic responses for PHiD-CV [29].…”

“…While the authors highlighted a number of ongoing issues with serotype 19A worldwide, they make a number of claims for which no supporting data was provided, or provided only selective data, not representative of the body of evidence, potentially misleading the reader. While not discussed in detail here, the cost-effectiveness results that Isturiz et al allude to are also based on inaccurate assumptions around 19A efficacy for PHiD-CV as well as those around indirect protection and acute otitis media efficacy, and we refer the reader to a previous correction of these assumptions [2].…”

“…The World Health Organization (WHO) has clearly stated that the population-derived IgG antibody threshold value should not be interpreted to mean that achievement of ≥0.35 μg/ml for a specific serotype predicts protection against invasive pneumococcal disease (IPD) due to that serotype in an individual subject [3]. PCV13 appears to be more immunogenic than PHiD-CV in relation to serotype 19A; however, the observed IPD VE in well-designed studies for this serotype is similar in vaccineeligible cohorts of children for both vaccines as reviewed previously [2,[4][5][6][7][8][9][10][11][12][13][14]. Conversely, serotype 3 was quite immunogenic in PCV13 vaccinated individuals, with post-primary anti-3 IgG concentrations increasing 19-fold compared to baseline [15].…”

“…Conversely, serotype 3 was quite immunogenic in PCV13 vaccinated individuals, with post-primary anti-3 IgG concentrations increasing 19-fold compared to baseline [15]. As per the hypothetical correlate of protection, 100% of these subjects should have sero-protective antibody levels; however, PCV13 VE against serotype 3 has not been consistently demonstrated, with serotype-specific VE estimates reported by the majority of studies being not significantly different from zero [2,12]. Importantly, a recent product evaluation conducted by the International Vaccines Access Center (IVAC) at Johns Hopkins Bloomberg School of Public Health in association with the WHO concluded that there was inconsistent evidence of PCV13 on serotype 3 [16].…”