A systematic review of health economic evaluations of vaccines in Brazil

An Umbrella Review of the Cost Effectiveness of Human Papillomavirus Vaccines

BACKGROUND AND OBJECTIVES

Although many systematic reviews for the human papillomavirus vaccines cost effectiveness have been published, they vary in perspectives, methods, and quality. We aimed to condense systematically such evidence to facilitate locating, processing, and learning, not only about the consensus of findings but also how models were built and their evolution over time and across settings.

METHODS

We conducted an umbrella review of cost-effectiveness studies for human papillomavirus vaccines using three databases (PubMed, Embase, and Cochrane). Based on their objectives, we classified studies into three groups (human papillomavirus vaccines cost effectiveness, model characteristics, and all-type vaccines, including human papillomavirus vaccines). We used the AMTAR2 to assess the quality of the studies. Additionally, we provided a summary of study findings, discussions, and evidence gaps in the literature.

RESULTS

Though most studies were critically low quality and had a low quality of reporting, the human papillomavirus vaccine was consistently cost effective in young girls and men who have sex with men. Stratified analyses by rated quality did not change the results. The quality assessment of the reviews did not necessarily reflect the quality assessment of underlying studies. The human papillomavirus vaccine models became more complex over time, capturing more realistic disease transmission with different human papillomavirus strains and herd immunities.

CONCLUSIONS

Additional evidence is needed for vulnerable populations (e.g., childhood cancer survivors) who are at high risk for human papillomavirus vaccine-related cancers and, therefore, may be more cost effective when receiving human papillomavirus vaccines. Quantifying human papillomavirus vaccine cost effectiveness via meta-analyses is feasible if investigators can increase the homogeneity of their populations.

A systematic review of economic evaluations of vaccines in Middle East and North Africa countries: is existing evidence good enough to support policy decision-making?

INTRODUCTION

A vaccine introduction process should be systematic and transparent and take into account many factors, including cost-effectiveness evidence. This study aimed to assess quantity, characteristic, and quality of economic evaluation (EE) studies on vaccines performed in Middle East and North Africa (MENA) countries.

AREAS COVERED

PubMed and Scopus electronic databases were searched since inception to December 2019 to identify published EE studies of vaccines, which were conducted in the 26 MENA countries. Methodological quality of the included studies was evaluated using the Consolidated Health Economic Evaluation Reporting Standards (CHEERS) checklist.

EXPERT OPINION

Of the 616 studies identified, 46 were included in the review. Most studies (65%) were conducted in Iran, Israel, and Turkey. The most commonly evaluated vaccines were rotavirus vaccine (n = 15; 33%), human Papillomavirus vaccine (n = 8; 17%), and pneumococcal vaccine (n = 7; 15%). We classified 5 (11%), 27 (59%), 12 (26%), and 2 (4%) studies as excellent, good, moderate, and poor quality, respectively. There were limited cost-effectiveness evidences in the region. It is imperative to have local guidelines on good practice and reporting, availability of local data, and funding sources to improve quantity and quality of EE studies of vaccines in the region, thereby, facilitating transparent and consistent decision-making processes.

Mathematical assessment of the impact of cohort vaccination on pneumococcal carriage and serotype replacement

Although pneumococcal vaccines are quite effective in reducing disease burden, factors such as imperfect vaccine efficacy and serotype replacement present an important challenge against realizing direct and herd protection benefits of the vaccines. In this study, a novel mathematical model is designed and used to describe the dynamics of two Streptococcus pneumoniae (SP) serotypes, in response to the introduction of a cohort vaccination program which targets one of the two serotypes. The model is fitted to a pediatric SP carriage prevalence data from Atlanta, GA. The model, which is rigorously analysed to investigate the existence and asymptotic stability properties of the associated equilibria (in addition to exploring conditions for competitive exclusion), is simulated to assess the impact of vaccination under different levels of serotype-specific competition and illustrate the phenomenon of serotype replacement. The calibrated model is used to forecast the carriage prevalence in the pediatric cohort over 30 years.

Impact of quadrivalent influenza vaccines in Brazil: a cost-effectiveness analysis using an influenza transmission model

BACKGROUND

Influenza epidemics significantly weight on the Brazilian healthcare system and its society. Public health authorities have progressively expanded recommendations for vaccination against influenza, particularly to the pediatric population. However, the potential mismatch between the trivalent influenza vaccine (TIV) strains and those circulating during the season remains an issue. Quadrivalent vaccines improves vaccines effectiveness by preventing any potential mismatch on influenza B lineages.

METHODS

We evaluate the public health and economic benefits of the switch from TIV to QIV for the pediatric influenza recommendation (6mo-5yo) by using a dynamic epidemiological model able to consider the indirect impact of vaccination. Results of the epidemiological model are then imputed in a health-economic model adapted to the Brazilian context. We perform deterministic and probabilistic sensitivity analysis to account for both epidemiological and economical sources of uncertainty.

RESULTS

Our results show that switching from TIV to QIV in the Brazilian pediatric population would prevent 406,600 symptomatic cases, 11,300 hospitalizations and almost 400 deaths by influenza season. This strategy would save 3400 life-years yearly for an incremental direct cost of R$169 million per year, down to R$86 million from a societal perspective. Incremental cost-effectiveness ratios for the switch would be R$49,700 per life-year saved and R$26,800 per quality-adjusted life-year gained from a public payer perspective, and even more cost-effective from a societal perspective. Our results are qualitatively similar in our sensitivity analysis.

CONCLUSIONS

Our analysis shows that switching from TIV to QIV to protect children aged 6mo to 5yo in the Brazilian influenza epidemiological context could have a strong public health impact and represent a cost-effective strategy from a public payer perspective, and a highly cost-effective one from a societal perspective.

Retrospective study of immunization errors reported in an online Information System

Objective:

to analyze the immunization errors reported in an online Information System.

Method:

retrospective study conducted with data from the Adverse Event Following Immunization Surveillance Information System. Immunization errors were analyzed with respect to demographic characteristics and the vaccination process. Frequencies and error incidence rates have been calculated. Binomial and chi-square tests were used to verify differences in the proportions of the variables.

Results:

501 errors were analyzed, the majority involving routine doses (92.6%), without Adverse Event Following Immunization (90.6%) and in children under five years old (55.7%). The most frequent types of errors were inadequacy in the indication of the immunobiological (26.9%), inadequate interval between doses (18.2%) and error in the administration technique (14.2%). The overall error incidence rate was 4.05/100,000 doses applied; the highest incidences of routine vaccines were for human rabies vaccine, human papillomavirus and triple viral; the incidence rate of errors with Adverse Events Following Immunization was 0.45/100,000 doses applied.

Conclusion:

it was found that immunization errors are a reality to be faced by the health systems, but they are amenable to prevention through interventions such as the adoption of protocols, checklists and permanent education in health.