Cost-effectiveness evaluation of gender-based vaccination programs against sexually transmitted infections

Jane M. Heffernan; Yijun Lou; Marc Steben; Jianhong Wu

doi:10.3934/dcdsb.2014.19.447

Article Contents

2014, Volume 19, Issue 2: 447-466. Doi: 10.3934/dcdsb.2014.19.447

This issue Previous Article Volatility in options formulae for general stochastic dynamics Next Article Traveling wave solutions of a nonlocal delayed SIR model without outbreak threshold

Cost-effectiveness evaluation of gender-based vaccination programs against sexually transmitted infections

1.
Mprime Centre for Disease Modelling, York Institute of Health Research, Department of Mathematics and Statistics, York University, Toronto, Ontario, M3J 1P3
2.
Department of Applied Mathematics, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong
3.
Medical advisor, Direction des risques biologiques et de la santé au travail, Institut national de santé publique du Québec, Montréal

Received: March 31, 2013

Revised: September 30, 2013

Published: February 2014

Abstract Related Papers Cited by

Abstract

The ultimate goal of a vaccination program is to interrupt pathogen transmission so as to eradicate the disease from the population in the future, and/or to decrease morbidity and mortality due to the disease in the short term. For sexually transmitted infections (STI) the determination of an optimal vaccination program is not straightforward since (1) the transmission probabilities between two different sexes are normally unequal (weighted to a greater probability from males to females than vice versa), (2) demographic parameters between the two sexes are unequal, (3) the prevalence of disease in one sex may have a greater impact on the morbidity and mortality of the next generation (transmission to the neonate) and, (4) the existence of pathogens closely related to the STI in question (i.e. herpes - HSV-1 vs. HSV-2, different strains of Chlamydia trachomatis, different strains of Neisseria which cause Gonorrhea, and others) may induce immunity in individuals that render a vaccine ineffective.
We have developed two models of sexually transmitted infections (with and without age structure) to evaluate the cost-efficacy of gender-based vaccination programs in the context of STI control. The first model ignores age structure for qualitative analysis of points (1-3), while the second refined one incorporates the age structure, reflecting the effects of immunity gained from infection of closely related strains (point 4), which is important for HSV-2 vaccination strategies. For both models, we find that the stability of the system and ultimate eradication of the disease depends explicitly on the corresponding reproduction number. We also find that vaccinating females is more cost-effective, providing a greater reduction in disease prevalence in the population and number of infected females of childbearing age. This result is counter-intuitive since vaccinating super-transmitters (males) over sub-transmitters (females) usually has the greatest impact on disease prevalence. Sensitivity analysis is implemented to investigate how the parameters affect the control reproduction numbers and infectious population sizes.

Keywords:

Mathematics Subject Classification: Primary: 37N25, 92D30; Secondary: 34D23.

Citation:

Related Papers

Cited by

References

[1]	American Social Health Association, Oral Herpes, Available at http://www.ashasexualhealth.org/std-sti/Herpes/oral-herpes.html.
[2]	R. M. Anderson, J. Swinton and G. P. Garnett, Potential impact of low efficacy HIV-1 vaccines in populations with high rates of infection, Proc. R. Soc. Lond. B, 261 (1995), 147-151.doi: 10.1098/rspb.1995.0129.
[3]	S. M. Blower and H. Dowlatabadi, Sensitivity and uncertainty analysis of complex models of disease transmission: An HIV model as an example, Int. Stat. Rev., 2 (1994), 229-243.doi: 10.2307/1403510.
[4]	V. L. Brown and K. A. J. White, The role of optimal control in assessing the most cost-effective implementation of a vaccination strategy: HPV as a case study, Math. Biosci., 231 (2011), 126-134.doi: 10.1016/j.mbs.2011.02.009.
[5]	Y. Bryson, M. Dillon, D. I. Bernstein, J. Radolf, P. Zakowski and E. Garratty, Risk of acquisition of genital herpes simplex virus type 2 in sex partners of persons with genital herpes: A prospective couple study, J. Infect. Dis., 167 (1993), 942-946.doi: 10.1093/infdis/167.4.942.
[6]	Centers for Disease Control and Prevention, Tracing the hidden epidemics: Trends in STIs in the United States, 2000.
[7]	M. S. Cohen, Sexually transmitted diseases enhance HIV transmission: No longer a hypothesis, Lancet, 351 (1998), 5-7.doi: 10.1016/S0140-6736(98)90002-2.
[8]	R. Cohen, S. Havlin and D. ben-Avraham, Efficient immunization strategies for computer networks and populations, Phys. Rev. Lett., 91 (2003), 247901.doi: 10.1103/PhysRevLett.91.247901.
[9]	M. E. Craft and D. Caillaud, Network Models: An Underutilized Tool in Wildlife Epidemiology, Interdiscip. Perspect. Infect. Dis., 2011 (2011), 676949.doi: 10.1155/2011/676949.
[10]	O. Diekmann, J. A. P. Heesterbeek and J. A. J. Metz, On the definition and the computation of the basic reproduction ratio $R_0$ in models for infectious diseases, J. Math. Biol., 28 (1990), 365-382.doi: 10.1007/BF00178324.
[11]	E. H. Elbasha and A. B. Gumel, Theoretical assessment of public health impact of imperfect prophylactic HIV-1 vaccines with therapeutic benefits, Bull. Math. Biol., 68 (2006), 577-614.doi: 10.1007/s11538-005-9057-5.
[12]	D. T. Fleming, G. M. McQuillan, R. E. Johnson, A. J. Nahmias, S. O. Aral, F. K. Lee and M. E. St. Louis, Herpes Simplex Virus Type 2 in the United States, 1976 to 1994, New. Engl. J. Med., 53 (1998), 134-136.doi: 10.1097/00006254-199803000-00003.
[13]	G. P. Garnett, G. Dubin and M. Slaoui, The potential epidemiological impact of a genital herpes vaccine for women, Sex. Transm. Infect., 80 (2004), 24-29.doi: 10.1136/sti.2002.003848.
[14]	J. M. Heffernan, R. J. Smith and L. M. Wahl, Perspectives on the basic reproductive ratio, J. R. Soc. Interface, 2 (2005), 281-293.doi: 10.1098/rsif.2005.0042.
[15]	J. P. Hughes, G. P. Garnett and L. Koutsky, The theoretical population-level impact of a prophylactic human papilloma virus vaccine, Epidemiology, 13 (2002), 631-639.doi: 10.1097/00001648-200211000-00006.
[16]	http://www12.statcan.ca/census-recensement/2006/dp-pd/hlt/97-550/Index.cfm?TPL=P1C&Page=RETR&LANG=Eng&T=101 , 97
[17]	http://www12.statcan.ca/census-recensement/2006/as-sa/97-551/tables-tableaux-notes-eng.cfm , 97
[18]	http://www45.statcan.gc.ca/2009/cgco_2009_002-eng.htm
[19]	M. Lipsitch, T. H. Bacon, J. J. Leary, R. Antia and B. R. Levin, Effects of antiviral usage on transmission dynamics of herpes simplex virus type 1 and on antiviral resistance: predictions of mathematical models, Antimicrob Agents Chemother, 44 (2000), 2824-2835.doi: 10.1128/AAC.44.10.2824-2835.2000.
[20]	M. Llamazares and R. J. Smith?, Evaluating human papillomavirus vaccination programs in Canada: Should provincial healthcare pay for voluntary adult vaccination? BMC Public Health, 8 (2008), 114.doi: 10.1186/1471-2458-8-114.
[21]	Y. Lou, R. Qesmi, Q. Wang, M. Steben, J. Wu and J. Heffernan, Epidemiological Impact of a Genital Herpes Type 2 Vaccine for Young Females, PLoS ONE, 7 (2012), e46027.doi: 10.1371/journal.pone.0046027.
[22]	M. V. Maciosek, A. B. Coffield, N. M. Edwards, T. J. Flottemesch, M. J. Goodman and L. I. Solberg, Priorities among effective clinical preventive services: results of a systematic review and analysis, Am. J. Prev. Med., 31 (2006), 52-61.
[23]	S. Marino, I. B. Hogue, C. J. Ray and D. E. Kirschner, A methodology for performing global uncertainty and sensitivity analysis in systems biology, J. Theor. Biol., 254 (2008), 178-196.doi: 10.1016/j.jtbi.2008.04.011.
[24]	P. Mayaud, S. Hawkes and D. Mabey, Advances in control of sexually transmitted diseases in developing countries, Lancet, 351 (1998), 29-32.doi: 10.1016/S0140-6736(98)90009-5.
[25]	G. J. Mertz, J. Benedetti, R. Ashley, S. A. Selke and L. Corey, Risk factors for the sexual transmission of genital herpes, Ann. Intern. Med., 116 (1992), 197-202.doi: 10.7326/0003-4819-116-3-197.
[26]	A. J. Nahmias, F. K. Lee and S. Beckman-Nahmias, Sero-epidemiological and sociological patterns of herpes simplex virus infection in the world, Scand. J. Infect. Dis. Suppl., 69 (1990), 19-36.
[27]	D. M. Patrick, M. Dawar, D. A. Cook, M. Krajden, H. C. Ng and M. L. Rekart, Antenatal seroprevalence of herpes simplex virus type 2 (HSV-2) in Canadian Women: HSV-2 Prevalence increases throughout the reproductive years, Sex. Transm. Dis., 28 (2001), 424-428.doi: 10.1097/00007435-200107000-00011.
[28]	C. N. Podder and A. B. Gumel, Qualitative dynamics of a vaccination model for HSV-2, IMA J. Appl. Math., 75 (2010), 75-107.doi: 10.1093/imamat/hxp030.
[29]	C. Podder and A. B. Gumel, Transmission dynamics of a two-sex model for herpes simplex virus Type II, Can. Appl. Math. Q., 17 (2009), 339-386.
[30]	Public Health Agency of Canada, Genital herpes simplex virus (HSV) infections, January 2008.
[31]	N. R. Roan and M. N. Starnbach, Conquering sexually transmitted diseases, Nat. Rev. Immunol., 8 (2008), 313-317.
[32]	E. J. Schwartz and S. Blower, Predicting the potential individual- and population-level effects of imperfect herpes simplex virus type 2 vaccines, J. Infect. Dis., 191 (2005), 1734-1746.doi: 10.1086/429299.
[33]	D. Siegel, E. Golden, A. E. Washington, S. A. Morse, M. T. Fullilove, J. A. Catania, B. Marin and S. B. Hulley, Prevalence and correlates of herpes simplex infections: the population-based AIDs in multiethnic neighborhood study, JAMA, 268 (1992), 1702-1708.doi: 10.1001/jama.1992.03490130090036.
[34]	L. R. Stanberry, S. L. Spruance, A. L. Cunningham, D. I. Bernstein, A. Mindel, S. Sacks, S. Tyring, F. Y. Aoki, M. Slaoui, M. Denis, P. Vandepapeliere and G. Dubin, Glycoprotein-Dadjuvant vaccine to prevent genital herpes, New. Engl. J. Med., 347 (2002), 1652-1661.
[35]	H. R. Thieme, Convergence results and a Poincare-Bendixson trichotomy for asymptotically autonomous differential equations, J. Math. Biol., 30 (1992), 755-763.doi: 10.1007/BF00173267.
[36]	P. van den Driessche and J. Watmough, Reproduction numbers and sub-threshold endemic equilibria for compartmental models of disease transmission, Math. Biosci., 180 (2002), 29-48.doi: 10.1016/S0025-5564(02)00108-6.
[37]	R. J. Whitley and J. W. Gnann, The epidemiology and clinical manifestations of herpes simplex virus infections, In The Human Herpesviruses, Raven Press, (eds: B. Roizman, R. J. Whitley and C. Lopez), New York, 1993.
[38]	F. Xu, M. R. Sternberg, B. J. Kottiri, G. M. McQuillan, F. K. Lee, A. J. Nahmias, S. M. Berman and L. E. Markowitz, Trends in herpes simplex virus type 1 and type 2 seroprevalence in the United States, J. Am. Med. Assoc., 296 (2006), 964-973.doi: 10.1001/jama.296.8.964.
[39]	X.-Q. Zhao, Dynamical Systems in Population Biology, Springer-Verlag, New York, 2003.
[40]	X.-Q. Zhao and Z. Jing, lobal asymptotic behavior in some cooperative systems of functional-differential equations, Can. Appl. Math. Q., 4 (1996), 421-444.