Public health and budget impacts of switching from a trivalent to a quadrivalent inactivated influenza vaccine in Paraguay.

This study aimed to investigate the public health and economic benefit of using a quadrivalent influenza vaccine (QIV) instead of a trivalent influenza vaccine (TIV) in past seasons in Paraguay. The budget impact of switching from TIV to QIV in the Immunization Program was also evaluated. The adapted model includes two modules. The first compared retrospectively Health and Economic outcomes resulting from the use of QIV instead of TIV. The second forecast the spending and savings that would be associated with the switch from TIV to QIV. Our findings estimate that the switch from TIV to QIV during the seasons 2012 to 2017 could have prevented around 2,600 influenza cases, 67 hospitalizations and 10 deaths. An alternative scenario using standardized estimates of the burden of influenza showed that 234 influenza-related hospitalizations and 29 deaths could have been prevented. The estimated annual budget impact of a full switch from TIV to QIV was around USD1,6 million both from the payer and societal perspectives. Those results are mainly driven by vaccine prices and coverage rate. In sum, this manuscript describes how the use of QIV instead of TIV could have prevented influenza cases and subsequent complications that led to hospitalizations and deaths. This could have generated savings for the health system and society, offsetting part of the additional investment needed to switch from TIV to QIV.

Switching from trivalent to quadrivalent inactivated influenza vaccines in Uruguay: a cost-effectiveness analysis.

We evaluated the cost-utility of replacing trivalent influenza vaccine (TIV) with quadrivalent influenza vaccine (QIV) in the current target populations in Uruguay. An existing decision-analytic static cost-effectiveness model was adapted for Uruguay. The population was stratified into age groups. Costs and outcomes were estimated for an average influenza season, based on observed rates from 2013 to 2019 inclusive. Introducing QIV instead of TIV in Uruguay would avoid around 740 additional influenza cases, 500 GP consultations, 15 hospitalizations, and three deaths, and save around 300 workdays, for the same vaccination coverage during an average influenza season. Most of the influenza-related consultations and hospitalizations would be avoided among children ≤4 and adults ≥65 years of age. Using QIV rather than TIV would cost an additional ~US$729,000, but this would be partially offset by savings in consultations and hospitalization costs. The incremental cost per quality-adjusted life-year (QALY) gained with QIV would be in the order of US$18,000 for both the payor and societal perspectives, for all age groups, and around US$12,000 for adults ≥65 years of age. The main drivers influencing the incremental cost-effectiveness ratio were the vaccine efficacy against the B strains and the percentage of match each season with the B strain included in TIV. Probabilistic sensitivity analysis showed that switching to QIV would provide a favorable cost-utility ratio for 50% of simulations at a willingness-to-pay per QALY of US$20,000. A switch to QIV is expected to be cost-effective for the current target populations in Uruguay, particularly for older adults.

Cost-effectiveness analysis of switching from a trivalent to a quadrivalent inactivated influenza vaccine in the Peruvian immunisation programme.

BACKGROUND: Seasonal influenza is an acute respiratory infection mostly caused by type A and B influenza viruses. The severe form of the infection can be life-threatening and lead to a significant burden. Vaccination is the most efficient way of preventing influenza infections and limit this burden. OBJECTIVES: To assess the cost-effectiveness of switching from a trivalent influenza vaccine (TIV) to a quadrivalent influenza vaccine (QIV) in the vaccination programme in Peru, and to evaluate the health and economic impact of reaching the vaccination coverage rate targeted by the Ministry of Health. METHODS: A decision-analytic static cost-effectiveness model, was adapted to the Peruvian setting under both payer and societal perspectives. RESULTS: A switch from TIV to QIV would prevent 29,126 additional cases (including 12,815 consultations), 54 hospitalisations, and 23 deaths related to influenza, mostly in the population <2 years-old and >60 years-old. This would lead to a saving of US $505,206 under the payer perspective, that would partially offset the investment necessary to introduce QIV into the immunisation programme. The resulting incremental cost-effectiveness ratio (ICER) is $16,649 per QALYs gained. The main drivers of the model results were vaccine efficacy against influenza B viruses, degree of match, vaccines prices and proportion of cases attributable to influenza B. The robustness of the results seems satisfactory as QIV has the probability of being a cost-effective strategy of 83.8% (considering a threshold of three GDP per capita). Reaching the coverage targeted by the Ministry of Health would result in health benefits and disease management savings, and lower ICERs. CONCLUSION: Introducing QIV instead of TIV in the Peruvian immunisation programme is expected to be a cost-effective strategy, especially in younger children and the elderly. The benefit of QIV would be even more important if the coverage targeted by the Ministry of Health would be reached in the most vulnerable groups.

Public health and economic impact of switching from a trivalent to a quadrivalent inactivated influenza vaccine in Mexico.

Most influenza vaccines in Mexico are trivalent, containing two influenza A strains and a single B strain. Quadrivalent influenza vaccines (QIVs) extend protection by including an additional B strain to cover both co-circulating B lineages. Here, we retrospectively estimated how a switch to QIV in Mexico would have impacted influenza-related health outcomes over the 2010/2011 to 2015/2016 influenza seasons, and prospectively estimated the budget impact of using QIV in Mexico's national immunization program from 2016/2017 to 2020/2021. For the retrospective estimation, we used an age-stratified static model incorporating Mexico-specific input parameters. For the prospective estimation, we used a budget impact model based on retrospective attack rates considering predicted future vaccination coverage. Between 2010/2011 and 2015/2016, a switch to QIV would have prevented 270,596 additional influenza cases, 102,000 general practitioner consultations, 140,062 days of absenteeism, 3,323 hospitalizations, and 312 deaths, saving Mex$214 million (US$10.8 million) in third-party payer costs. In the prospective analysis, a switch to QIV was estimated to prevent an additional 225,497 influenza cases, 85,000 general practitioner consultations, 116,718 days of absenteeism, 2,769 hospitalizations, and 260 deaths, saving Mex$178 million (US$9 million) in third-party payer costs over 5 years. Compared to the trivalent vaccine, the benefit and costs saved with QIV were sensitive to the distribution of influenza A vs. B cases and trivalent vaccine effectiveness against the mismatched B strain. These results suggest switching to QIV in Mexico would benefit healthcare providers and society by preventing influenza cases, morbidity, and deaths, and reducing associated use of medical resources.