PharmacoEconomics & Outcomes News 680 - 15 Jun 2013

Quadrivalent flu vax tops trivalentvax in the US

Using a quadrivalent influenza vaccine (containingtwo influenza A and two influenza B strains) saves costsand improves health outcomes compared with thecurrent scenario of vaccination with trivalent influenzavaccines (containing two influenza A and one influenzaB strain) in the US, according to results of two studiespresented at the ISPOR meeting.

Decision tree favours quadrivalent vaccineThe first study, funded by GlaxoSmithKline, used a

1-year decision tree from a societal perspective tocompare trivalent inactivated vaccine (TIV) and trivalentlive attenuated influenza vaccine to the quadrivalentvaccine (QIV) in an age-stratified population (< 5, 5–17,18–49, 50–64 and > 65 years).1 Influenza rates,healthcare utilisation, disease-related costs and survivalwere estimated from published data.

Compared with trivalent vaccination, quadrivalentvaccination resulted in 77 817 fewer medically-attendedcases of influenza, 868 fewer deaths, and 4342 fewerQALYs lost. Of note, the increase in vaccination costs($US385 million) were offset by a $411 millionreduction in influenza-related treatment costs –$142 million in direct medical costs and $269 million indirect non-medical costs.

Different model same resultThe second study, funded by MedImmune, used a

dynamic transmission model to investigate theepidemiologic and economic outcomes of switchingfrom TIV to QIV vaccination in the US using a payer anda societal perspective.2 Costs were valued in 2011 USdollars. Vaccine administration costs and influenzaburden costs were obtained from the literature whilemean private list prices were used for the variousvaccine brands on the market with price parity betweenTIV and QIV assumed. Reduction in QOL resulting fromclinically apparent influenza was set at 0.02 while QALYslost to mortality were estimated using age-specificprobability of influenza-related death. The model wassimulated over a 200-year period.

The model predicts QIV to prevent, in an averageseason, an additional 13.6 million influenza infections,5.5 million primary care consultations, almost80 000 hospitalisations and 5500 deaths compared toTIV – producing savings of $1.6 billion and $3.9 billionfrom a payer and societal perspective, respectively. Theauthors conclude that "replacing current trivalentinfluenza vaccines with quadrivalent equivalents, at thesame price, saves costs and produces substantial healthbenefits".1. Meier G, et al. Universal Mass Vaccination with Quadrivalent Influenza Vaccine

(Qiv) in the United States. 18th Annual International Meeting of theInternational Society for Pharmacoeconomics and Outcomes Research : abstr.PIN79, 18 May 2013.

2. Pitman RJ, et al. Cost-Effectiveness Comparison of Quadrivalent VersusTrivalent Influenza Vaccines in the United States. 18th Annual InternationalMeeting of the International Society for Pharmacoeconomics and OutcomesResearch : abstr. PIN62, 18 May 2013.

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PharmacoEconomics & Outcomes News 15 Jun 2013 No. 6801173-5503/10/0680-0001/$14.95 Adis © 2010 Springer International Publishing AG. All rights reserved