Cost analysis of post-polio certification immunization policies

OBJECTIVE: An analysis was conducted to estimate the costs of different potential post-polio certification immunization policies currently under consideration, with the objective of providing this information to policy-makers. METHODS: We analyzed three global policy options: continued use of oral poliovirus vaccine (OPV); OPV cessation with optional inactivated poliovirus vaccine (IPV); and OPV cessation with universal IPV. Assumptions were made on future immunization policy decisions taken by low-, middle-, and high-income countries. We estimated the financial costs of each immunization policy, the number of vaccine-associated paralytic poliomyelitis (VAPP) cases, and the global costs of maintaining an outbreak response capacity. The financial costs of each immunization policy were based on estimates of the cost of polio vaccine, its administration, and coverage projections. The costs of maintaining outbreak response capacity include those associated with developing and maintaining a vaccine stockpile in addition to laboratory and epidemiological surveillance. We used the period 2005-20 as the time frame for the analysis. FINDINGS: OPV cessation with optional IPV, at an estimated cost of US$ 20,412 million, was the least costly option. The global cost of outbreak response capacity was estimated to be US$ 1320 million during 2005-20. The policy option continued use of OPV resulted in the highest number of VAPP cases. OPV cessation with universal IPV had the highest financial costs, but it also had the least number of VAPP cases. Sensitivity analyses showed that global costs were sensitive to assumptions on the cost of the vaccine. Analysis also showed that if the price per dose of IPV was reduced to US$ 0.50 for low-income countries, the cost of OPV cessation with universal IPV would be the same as the costs of continued use of OPV. CONCLUSION: Projections on the vaccine price per dose and future coverage rates were major drivers of the global costs of post-certification polio immunization. The break-even price of switching to IPV compared with continuing with OPV immunizations is US$ 0.50 per dose of IPV. However, this doses not account for the cost of vaccine-derived poliovirus cases resulting from the continued use of OPV. In addition to financial costs, risk assessments related to the re-emergence of polio will be major determinants of policy decisions.     

Cost-effectiveness analysis of changing from live oral poliovirus vaccine to inactivated poliovirus vaccine in Australia

OBJECTIVE: Estimate the economic impact of introducing inactivated poliovirus vaccine (IPV) into the Australian childhood immunisation schedule to eliminate vaccine-associated paralytic poliomyelitis (VAPP). METHODS: Cost-effectiveness of two different four-dose IPV schedules (monovalent vaccine and IPV-containing combination vaccine) compared with the current four-dose oral poliovirus vaccine (OPV) schedule for Australian children through age six years. Model used estimates of VAPP incidence, costs, and vaccine utilisation and price obtained from published and unpublished sources. Main outcome measures were total costs, outcomes prevented, and incremental cost-effectiveness, expressed as net cost per case of VAPP prevented. RESULTS: Changing to an IPV-based schedule would prevent 0.395 VAPP cases annually. At $20 per dose for monovalent vaccine and $14 per dose for the IPV component in a combination vaccine, the change would incur incremental, annual costs of $19.5 million ($49.3 million per VAPP case prevented) and $6.7 million ($17.0 million per VAPP case prevented), respectively. Threshold analysis identified break-even prices per dose of $1 for monovalent and $7 for combination vaccines. CONCLUSIONS: Introducing IPV into the Australian childhood immunisation schedule is not likely to be cost-effective unless it comes in a combined vaccine with the IPV-component price below $10. IMPLICATIONS: More precise estimates of VAPP incidence in Australia and IPV price are needed. However, poor cost-effectiveness will make the decision about switching from OPV to IPV in the childhood schedule difficult.     

PER.C6 cells as a serum-free suspension cell platform for the production of high titer poliovirus: A potential low cost of goods option for world supply of inactivated poliovirus vaccine

There are two highly efficacious poliovirus vaccines: Sabin's live-attenuated oral polio vaccine (OPV) and Salk's inactivated polio vaccine (IPV). OPV can be made at low costs per dose and is easily administrated. However, the major drawback is the frequent reversion of the OPV vaccine strains to virulent poliovirus strains which can result in Vaccine Associated Paralytic Poliomyelitis (VAPP) in vaccinees. Furthermore, some OPV revertants with high transmissibility can circulate in the population as circulating Vaccine Derived Polioviruses (cVDPVs). IPV does not convey VAPP and cVDPVs but the high costs per dose and insufficient supply have rendered IPV an unfavorable option for low and middle-income countries.     

End phase challenges of poliomyelitis eradication programme realization

The progress of poliomyelitis eradication programme realization, the implementation schedule and strategies for the future, are summarised based on publications of the World Health Organisation. During the following two years wild poliovirus strains should be globally eradicated. This means that potentially in 2010 the global eradication of wild polioviruses will be certified. To eradicate poliomyelitis, cessation of the oral polio vaccine (OPV) is necessary, since the vaccine strains produce cases of vaccine-associated paralytic poliomyelitis (VAPP) and cases of poliomyelitis caused by circulating vaccine-derived poliovirus (cVDPV). However, the WHO plan to stop immunization with OPV and the immunization with inactivated polio vaccine (IPV) shortly after, is alarming in the present situation. The article describes the measures undertaken to prevent or minimise the risk of reintroduction of wild poliovirus strains, which is potentially associated with WHO plan of action.     

Imported vaccine-associated paralytic poliomyelitis--United States, 2005

Paralytic poliomyelitis is rare in the United States because of the success of universal childhood immunization and the Global Polio Eradication Initiative. Poliovirus vaccine was introduced in the 1950s. Since then, the United States has eliminated indigenous wild poliovirus transmission, controlled imported wild poliovirus cases, and, through a vaccine policy change (i.e., from live, attenuated oral polio vaccine [OPV] to inactivated polio vaccine [IPV]), eliminated vaccine-associated paralytic polio (VAPP) cases. The most recent VAPP case occurred in 1999. The primary risk for paralytic polio for U.S. residents is through travel to countries where polio remains endemic or where polio outbreaks are occurring. This report describes the first known occurrence of imported VAPP in an unvaccinated U.S. adult who traveled abroad, where she likely was exposed through contact with an infant recently vaccinated with OPV. This case highlights the previously unrecognized risk for paralytic polio among unvaccinated persons exposed to OPV during travel abroad.     

World wide experience with inactivated poliovirus vaccine

As part of the global poliovirus eradication strategy, oral poliovirus vaccine (OPV) has successfully contributed to reduce polio incidence rates globally. However, because of the OPV-related risks of vaccine associated paralytic poliomyelitis (VAPP) and vaccine-derived polioviruses (VDPVs) OPV cessation is required in order to achieve complete eradication of polio. Inactivated poliovirus vaccine (IPV) is a viable option for incorporation into existing vaccination schedules so as to avoid these risks. Furthermore, the continuation of vaccination with IPV will protect populations in case of re-emergence of wild-type poliovirus from remote locations, laboratory samples, or through bioterrorism. The ability of IPV to prevent poliovirus outbreaks and provide herd protection has been demonstrated in several circumstances and in various settings. This paper reviews clinical experiences with IPV administration and outcomes in various countries in Europe, the Americas, Africa and Asia.     

Poliomyelitis prevention in the United States. Updated recommendations of the Advisory Committee on Immunization Practices (ACIP).

These recommendations of the Advisory Committee on Immunization Practices (ACIP) for poliomyelitis prevention replace those issued in 1997. As of January 1, 2000, ACIP recommends exclusive use of inactivated poliovirus vaccine (IPV) for routine childhood polio vaccination in the United States. All children should receive four doses of IPV at ages 2, 4, and 6-18 months and 4-6 years. Oral poliovirus vaccine (OPV) should be used only in certain circumstances, which are detailed in these recommendations. Since 1979, the only indigenous cases of polio reported in the United States have been associated with the use of the live OPV. Until recently, the benefits of OPV use (i.e., intestinal immunity, secondary spread) outweighed the risk for vaccine-associated paralytic poliomyelitis (VAPP) (i.e., one case among 2.4 million vaccine doses distributed). In 1997, to decrease the risk for VAPP but maintain the benefits of OPV, ACIP recommended replacing the all-OPV schedule with a sequential schedule of IPV followed by OPV. Since 1997, the global polio eradication initiative has progressed rapidly, and the likelihood of poliovirus importation into the United States has decreased substantially. In addition, the sequential schedule has been well accepted. No declines in childhood immunization coverage were observed, despite the need for additional injections. On the basis of these data, ACIP recommended on June 17, 1999, an all-IPV schedule for routine childhood polio vaccination in the United States to eliminate the risk for VAPP. ACIP reaffirms its support for the global polio eradication initiative and the use of OPV as the only vaccine recommended to eradicate polio from the remaining countries where polio is endemic.     

A developing country perspective on vaccine-associated paralytic poliomyelitis

When the Expanded Programme on Immunization was established and oral poliovirus vaccine (OPV) was introduced for developing countries to use exclusively, national leaders of public health had no opportunity to make an informed choice between OPV and the inactivated poliovirus vaccine (IPV). Today, as progress is made towards the goal of global eradication of poliomyelitis attributable to wild polioviruses, all developing countries where OPV is used face the risk of vaccine-associated paralytic poliomyelitis (VAPP). Until recently, awareness of VAPP has been poor and quantitative risk analysis scanty but it is now well known that the continued use of OPV perpetuates the risk of VAPP. Discontinuation or declining immunization coverage of OPV will increase the risk of emergence of circulating vaccine-derived polioviruses (cVDPV) that re-acquire wild virus-like properties and may cause outbreaks of polio. To eliminate the risk of cVDPV, either very high immunization coverage must be maintained as long as OPV is in use, or IPV should replace OPV. Stopping OPV without first achieving high immunization coverage with IPV is unwise on account of the possibility of emergence of cVDPV. Increasing numbers of developed nations prefer IPV, and manufacturing capacities have not been scaled up, so its price remains prohibitively high and unaffordable by developing countries, where, in addition, large-scale field experience with IPV is lacking. Under these circumstances, a policy shift to increase the use of IPV in national immunization programmes in developing countries is a necessary first step; once IPV coverage reaches high levels (over 85%), the withdrawal of OPV may begin.     

Introduction of inactivated polio vaccine (IPV) into the routine immunization schedule of South Africa

South Africa is currently the only country on the African continent using inactivated polio vaccine (IPV) for routine immunization in a sequential schedule in combination with oral polio vaccine (OPV). IPV is a component of an injectable pentavalent vaccine introduced nationwide in April 2009 and administered according to EPI schedule at 6, 10 and 14 weeks with a booster dose at 18 months. OPV is administered at birth and together with the first IPV dose at 6 weeks, which stimulates gut immune system producing a memory IgA response (OPV), followed by IPV to minimize the risk of vaccine associated paralytic polio (VAPP). OPV is also given to all children under 5 years of age as part of regular mass immunizations campaigns. The decision to incorporate IPV into the routine schedule was not based on cost-effectiveness, which it is not. Other factors were taken into account: Firstly, the sequence benefits from the initial mucosal contact with live(vaccine) virus which promotes the IgA response from subsequent IPV, as well as herd immunity from OPV, together with the safety of IPV. Secondly, given the widespread and increasing use of IPV in the developed world, public acceptance of vaccination in general is enhanced in South Africa which is classified as an upper middle income developing country. Thirdly, to address equity concerns because of the growing use of IPV in the private sector. Fourthly, the advent of combination vaccines facilitated the incorporation of IPV into the EPI schedule.     

Economic analysis for evidence-based policy-making on a national immunization program: a case of rotavirus vaccine in Thailand

Severe diarrhea caused by rotavirus is a health problem worldwide, including Thailand. The World Health Organization has recommended incorporating rotavirus vaccination into national immunization programs. This policy has been implemented in several countries, but not in Thailand where the mortality rate is not high. This leads to the question of whether it would be cost-effective to implement such a policy. The Thai National Vaccine Committee, through the Immunization Practice Subcommittee, has conducted an economic analysis. Their study aimed to estimate the costs of rotavirus diarrhea and of a rotavirus vaccination program, and the cost-effectiveness of such a program including budget impact analysis. The study was designed as an economic evaluation, employing modeling technique in both provider and societal perspectives. A birth cohort of Thai children in 2009 was used in the analysis, with a 5-year time horizon. Costs were composed of cost of the illness and the vaccination program. Outcomes were measured in the form of lives saved and DALYs averted. Both costs and outcomes were discounted at 3%. The study found the discounted number of deaths to be 7.02 and 20.52 for vaccinated and unvaccinated cohorts, respectively (13.5 deaths averted). Discounted DALYs were 263.33 and 826.57 for vaccinated and unvaccinated cohorts, respectively (563.24 DALYs averted). Costs of rotavirus diarrhea in a societal perspective were US$6.6 million and US$21.0 million for vaccinated and unvaccinated cohorts, respectively. At base case, the costs per additional death averted were US$5.1 million and US$5.7 for 2-dose and 3-dose vaccines, respectively, in a societal perspective. Costs per additional DALYs averted were US$128,063 and US$142,144, respectively. In a societal perspective, with a cost-effectiveness threshold at 1 GDP per capita per DALYs averted, vaccine prices per dose were US$4.98 and US$3.32 for 2-dose and 3-dose vaccines, respectively; in a provider perspective, they were US$2.90 and US$1.93. One-way and probabilistic sensitivity analyses were included. The budget required for vaccine purchase was calculated for all scenarios.     

Parental attitudes toward multiple poliovirus injections following a provider recommendation

OBJECTIVES: Changes to the polio vaccination schedule, first to a sequential inactivated poliovirus/oral poliovirus (IPV/OPV) schedule in 1996 and most recently to an all-IPV schedule, require infants to receive additional injections. Some surveys show parental hesitation concerning extra injections, whereas others show that parents prefer multiple simultaneous injections over extra immunization visits. This study describes parental behavior and attitudes about the poliovirus vaccine recommendations and additional injections at the 2- and 4-month immunization visits. METHODS: Beginning July 1, 1996, providers in eight public health clinics in Cobb and Douglas Counties, Georgia, informed parents of polio vaccination options and recommended the IPV/OPV sequential schedule. A cross-sectional clinic exit survey was conducted from July 15, 1996, to January 31, 1997, with parents whose infants (younger than 6 months) were eligible for a first poliovirus vaccination. RESULTS: Of approximately 405 eligible infants, parents of 293 infants were approached for an interview, and 227 agreed to participate. Of those 227 participants, 210 (92%) parents chose IPV for their infant and 17 (8%) chose OPV. Of greatest concern to most parents was vaccine-associated paralytic polio (VAPP) (155, or 68.3%); the next greatest concern was an extra injection (22, or 9.7%). These parental concerns were unrelated to the number of injections the infant actually received. CONCLUSIONS: After receiving information on polio vaccination options and a provider recommendation, parents overwhelmingly chose IPV over OPV. Concern about VAPP was more common than objection to an extra injection. The additional injection that results from using IPV for an infant's first poliovirus vaccination appears to be acceptable to most parents.     

Cost-effectiveness of Haemophilus influenzae type b vaccine in Vietnam

BackgroundWith GAVI support, Vietnam introduced Haemophilus influenzae type b (Hib) vaccine in 2010 without evidence on cost-effectiveness. We aimed to analyze the cost-effectiveness of Hib vaccine from societal and governmental perspectives.MethodWe constructed a decision-tree cohort model to estimate the costs and effectiveness of Hib vaccine versus no Hib vaccine for the 2011 birth cohort. The disease burden was estimated from local epidemiologic data and literature. Vaccine delivery costs were calculated from governmental reports and 2013 vaccine prices. A prospective cost-of-illness study was conducted to estimate treatment costs. The human capital approach was employed to estimate productivity loss. The incremental costs of Hib vaccine were divided by cases, deaths, and disability-adjusted life years (DALY) averted. We used the WHO recommended cost-effectiveness thresholds of an intervention being highly cost-effective if incremental costs per DALY were below GDP per capita.ResultFrom the societal perspective, incremental costs per discounted case, death and DALY averted were US$ 6252, US$ 26,476 and US$ 1231, respectively; the break-even vaccine price was US$ 0.69/dose. From the governmental perspective, the results were US$ 6954, US$ 29,449, and US$ 1373, respectively; the break-even vaccine price was US$ 0.48/dose. Vietnam's GDP per capita was US$ 1911 in 2013. In deterministic sensitivity analysis, morbidity and mortality parameters were among the most influential factors. In probabilistic sensitivity analysis, Hib vaccine had an 84% and 78% probability to be highly cost-effective from the societal and governmental perspectives, respectively.ConclusionHib vaccine was highly cost-effective from both societal and governmental perspectives. However, with GAVI support ending in 2016, the government will face a six-fold increase in its vaccine budget at the 2013 vaccine price. The variability of vaccine market prices adds an element of uncertainty. Increased government commitment and improved resource allocation decision making will be necessary to retain Hib vaccine.     

Vaccine-associated paralytic poliomyelitis in India during 1999: decreased risk despite massive use of oral polio vaccine

OBJECTIVE: Vaccine-associated paralytic poliomyelitis (VAPP) is a rare but serious consequence of the administration of oral polio vaccine (OPV). Intensified OPV administration has reduced wild poliovirus transmission in India but VAPP is becoming a matter of concern. METHODS: We analysed acute flaccid paralysis (AFP) surveillance data in order to estimate the VAPP risk in this country. VAPP was defined as occurring in AFP cases with onset of paralysis in 1999, residual weakness 60 days after onset, and isolation of vaccine-related poliovirus. Recipient VAPP cases were a subset with onset of paralysis between 4 and 40 days after receipt of OPV. FINDINGS: A total of 181 AFP cases met the case definition. The following estimates of VAPP risk were made: overall risk, 1 case per 4.1 to 4.6 million OPV doses administered; recipient risk,1 case per 12.2 million; first-dose recipient risk, 1 case per 2.8 million; and subsequent-dose recipient risk, 1 case per 13.9 million. CONCLUSION: On the basis of data from a highly sensitive surveillance system the estimated VAPP risk in India is evidently lower than that in other countries, notwithstanding the administration of multiple OPV doses to children in mass immunization campaigns.     

不同序贯程序的脊髓灰质炎灭活疫苗和减毒活疫苗的免疫效果研究

目的 评价脊髓灰质炎灭活疫苗（IPV）和减毒活疫苗（OPV）不同序贯免疫程序的免疫效果。方法 选取月龄≥2月的婴儿,分为1剂IPV和2剂OPV序贯组(I - O - O组)、2剂IPV和1剂OPV序贯组(I - I - O组)、IPV全程(I - I - I组)和OPV全程组(O - O - O),分别在2、3、4月龄时各接种1针,检测并比较各组人群血清中脊髓灰质炎中和抗体几何平均滴度（GMT）及抗体阳转率。结果 在完成基础免疫后,I - O - O 组Ⅰ、Ⅱ、Ⅲ型抗体GMT分别为948.78、930.91、955.08;I - I - O组抗体GMT分别为909.43、1 202.34、1 102.83;I - I - I 组GMT分别为333.02、298.56、411.98,O - O - O组抗体GMT分别为814.42、778.27、658.52;差异均有统计学意义;各组3个型别的抗体阳转率均为98％~100％,差异无统计学意义。接种1针IPV后脊髓灰质炎Ⅰ型、Ⅱ型、Ⅲ型中和抗体GMT分别为21.77、30.89、26.46,抗体阳转率分别为84.1％、91.5％、91.5％;接种第2剂IPV后,Ⅰ型、Ⅱ型、Ⅲ型中和抗体GMT分别69.42、133.89、212.58,抗体阳转率分别为100.0％、100.0％、99.9％。结论 IPV与OPV序贯接种后,对象产生的脊髓灰质炎中和抗体GMT比单独接种3剂IPV或3剂OPV高;不同序贯程序中,接种2剂IPV后抗体保护率较高。为了使机体产生更高的抗体水平并且避免疫苗相关麻痹病例发生,可采用IPV与OPV序贯程序,并以2剂IPV和1剂OPV的序贯程序为佳。     

Cost-effectiveness of the introduction of two-dose bi-valent (Cervarix) and quadrivalent (Gardasil) HPV vaccination for adolescent girls in Bangladesh

BackgroundCervical cancer is one of the most prevalent cancers in women caused by the human papillomavirus (HPV) that leads to a substantial disease burden for health systems. Prevention through vaccination can significantly reduce the prevalence of cervical cancer. The objective of this study is to evaluate the potential health and economic impacts of introducing two-dose bivalent (Cervarix) and quadrivalent (Gardasil) HPV vaccines in Bangladesh.MethodsThe study uses the Papillomavirus Rapid Interface for Modelling and Economics (PRIME) model to assess the cost-effectiveness of introducing HPV vaccination. The incremental cost-effectiveness ratios (ICERs) were estimated per disability-adjusted life years (DALYs) averted using the cost-effectiveness threshold (CET). The analyses were done from a health system perspective in terms of vaccine delivery routes.ResultsIntroduction of bi-valent HPV vaccination was found highly cost-effective (ICER = US$488/DALY) at Gavi (The Vaccine Alliance for Vaccines and Immunizations) negotiated prices. The value of ICERs were US$710, US$356 and US$397 per DALY averted for school-based, health facility-based, and outreach-based programs, respectively, which is consistent with the CET range (US$67 to US$854). However, bivalent and quadrivalent vaccines at listed prices were not found cost-effective, with ICERs of US$1405 and US$3250 per DALY averted, respectively, that exceeds the CETs values.ConclusionsIntroducing a two-dose bi-valent HPV vaccination program is cost-effective in Bangladesh at Gavi negotiated prices. Vaccine price is the dominating parameter for the cost-effectiveness of bivalent and quadrivalent vaccines. Both vaccines are not cost-effective at listed prices in Bangladesh. The evaluation highlights that introducing the two-dose bivalent HPV vaccine at Gavi negotiated prices into a national immunization program in Bangladesh is economically viable to reduce the burden of cervical cancer.     

Paralytic poliomyelitis associated with Sabin monovalent and bivalent oral polio vaccines in Hungary

Historical records of patients with vaccine-associated paralytic poliomyelitis (VAPP) in Hungary during 1961-1981 were reviewed to assess the risk of VAPP after oral polio vaccine (OPV) administration. A confirmed VAPP case was defined as a diagnosis of paralytic poliomyelitis and residual paralysis at 60 days in a patient with an epidemiologic link to the vaccine. Archived poliovirus isolates were retested using polymerase chain reaction and sequencing of the viral protein 1 capsid region. This review confirmed 46 of 47 cases previously reported as VAPP. Three cases originally linked to monovalent OPV (mOPV) 3 and one case linked to mOPV1 presented after administration of bivalent OPV 1 + 3 (bOPV). The adjusted VAPP risk per million doses administered was 0.18 for mOPV1 (2 cases/11.13 million doses), 2.96 for mOPV3 (32 cases/10.81 million doses), and 12.82 for bOPV (5 cases/390,000 doses). Absence of protection from immunization with inactivated poliovirus vaccine or exposure to OPV virus from routine immunization and recent injections could explain the higher relative risk of VAPP in Hungarian children. In polio-endemic areas in which mOPV3 and bOPV are needed to achieve eradication, the higher risk of VAPP would be offset by the high risk of paralysis due to wild poliovirus and higher per-dose efficacy of mOPV3 and bOPV compared with trivalent OPV.     

The budget impact of controlling wastage with smaller vials: A data driven model of session sizes in Bangladesh,India (Uttar Pradesh), Mozambique,and Uganda

Introduction

Open vial vaccine wastage in multi-dose vials is a major contributor to vaccine wastage. Although switching from 10-dose vials to 5-dose vials could reduce wastage, a higher total cost could be triggered because smaller vials cost more to purchase and store.

Methods

This study drew field data of daily session sizes in local vaccination facilities from Bangladesh, India (Uttar Pradesh), Mozambique, and Uganda, and used Akaike Information Criteria to determine the best fit statistical distribution across various clinic types. These distributions were input to estimate the vaccine wastage using Lee's (2010) model. Inactivated polio vaccine (IPV) immunization was simulated to compare the costs over ten years with 10-dose vials versus 5-dose vials.

Results

By switching from 10- to 5-dose vials, the observed open vial wastage rate due to vial size preference and session size for IPV was reduced from 0.25 to 0.11 in Bangladesh, 0.17 to 0.08 in India (Uttar Pradesh), 0.13 to 0.06 in Mozambique, and 0.09 to 0.04 in Uganda, respectively. The cost savings realized from lower IPV wastage did not offset the higher costs of procurement and storage costs associated with smaller dose presentation.

Conclusion

While our model showed that switching from 10-dose vials to 5-dose vials of IPV reduced open vial wastage, it was not cost-saving.     

Economics of polio vaccination in the post-eradication era: should OPV-using countries adopt IPV?

The continued use of oral polio vaccine (OPV) poses a threat to polio virus eradication. Stopping all polio vaccination in the post-certification era is no longer considered to be a practical option. Policy makers agree that OPV use must stop immediately after certification. Therefore, the pragmatic alternative is for the OPV-using countries to switch to IPV. This study estimates the cost of switching to IPV, and the cost-effectiveness of this switch. Using data on the number of polio cases and the number of unvaccinated children in different countries of the world, the risks of polio and polio outbreaks have been calculated. The current cost of routine and intensive OPV immunisation is about US $2143 million in the 148 OPV-using countries. Routine use of IPV in these countries should cost US $1246 million. If the current costs of routine and intensive polio immunisation are considered, adopting IPV to replace OPV will not increase the total global cost. Even if the cost of intensive polio immunisation is ignored, cost-effectiveness ratio of adopting IPV remains less than the average GNI per capita of OPV-using countries. The incremental cost of adopting IPV to replace OPV is relatively low, about US $1 per child per year, and most countries should be able to afford this additional cost.     

The cost-effectiveness of introducing hepatitis B vaccine into infant immunization services in Mozambique

OBJECTIVE: To estimate the cost-effectiveness of introducing hepatitis B vaccine into routine infant immunization services in Mozambique, which took place in the year 2001. METHODS: A decision analytic model was used to estimate the impact of hepatitis B vaccination. This model was developed for the WHO to estimate the global burden of disease from hepatitis B. Cost data of vaccine delivery and medical treatment related to hepatitis B infection were collected for the analysis. FINDINGS: The introduction of hepatitis B vaccine has increased the annual budget for immunization services by approximately 56%. It is predicted that more than 4000 future deaths are averted annually by the intervention. In the base case scenario, the incremental costs per undiscounted deaths averted amount to US$436, and the costs per undiscounted DALY averted amount to US$36. Since the major impact of hepatitis B vaccination will not start to be evident for at least another 40 years (deaths from hepatitis B mainly occur between 40-60 years of age), the cost per DALY averted rises to US$47, when using a discount rate of 3% on health effects. We found that the monovalent hepatitis B vaccine was considerably more cost-effective than the hepatitis B vaccine in combination with DTP. INTERPRETATION: If policy makers value future health benefits equal to current benefits, the cost-effectiveness of infant hepatitis B vaccination is in the range of other primary health care interventions for which similar analysis has been undertaken.