Introduction of a hexavalent vaccine containing acellular pertussis into the national immunization program for infants in Peru: a cost-consequence analysis of vaccination coverage.

BACKGROUND: Infant vaccination coverage rates in Peru have declined in recent years, exacerbated by the COVID-19 pandemic. Introduction of the fully-liquid diphtheria, tetanus, and acellular pertussis (DTaP)-inactivated polio vaccine (IPV)-hepatitis B (HB)-Haemophilus influenzae type B (Hib) hexavalent vaccine (DTaP-IPV-HB-Hib) in Peru's infant National Immunization Program may help improve coverage. We evaluated costs and healthcare outcomes, including coverage, of switching from a pentavalent vaccine containing whole-cell pertussis component (DTwP-HB-Hib) plus IPV/oral polio vaccine (IPV/OPV) to the hexavalent vaccine for the primary vaccination scheme (2, 4 and 6 months). METHODS: The analysis was performed over a 5-year period on a cohort of children born in Peru in 2020 (N = 494,595). Four scenarios were considered: the pentavalent plus IPV/OPV scheme (S1); replacing the pentavalent plus IPV/OPV scheme with the hexavalent scheme (S2); expanded delivery of the pentavalent plus IPV/OPV scheme (S3); expanded delivery of the hexavalent scheme (S4). Vaccine coverage and incidence of adverse reactions (ARs) were estimated using Monte Carlo simulations and previous estimates from the literature. Cases of vaccine-preventable diseases were estimated using a Markov model. Logistical and healthcare costs associated with these outcomes were estimated. Impact of key variables (including coverage rates, incidence of ARs and vaccine prices) on costs was evaluated in sensitivity analyses. RESULTS: The overall cost from a public health payer perspective associated with the pentavalent plus IPV/OPV vaccine scheme (S1) was estimated at $56,719,350, increasing to $61,324,263 (+ 8.1%), $59,121,545 (+ 4.2%) and $64,872,734 (+ 14.4%) in scenarios S2, S3 and S4, respectively. Compared with the status quo (S1), coverage rates were estimated to increase by 3.1% points with expanded delivery alone, and by 9.4 and 14.3% points, if the hexavalent vaccine is deployed (S2 and S4, respectively). In both scenarios with the hexavalent vaccine (S2 and S4), pertussis cases would also be 5.7% and 8.7% lower, and AR rates would decrease by 32%. The cost per protected child would be reduced when the hexavalent vaccine scheme. Incidence of ARs was an important driver of cost variability in the sensitivity analysis. CONCLUSIONS: Implementation of the hexavalent vaccine in Peru's National Immunization Program has a positive public health cost consequence.

Clinical characteristics and pertussis costs in cases reported to epidemiological services and cases detected in household contacts in Catalonia (Spain).

PURPOSE: To assess the clinical characteristics and direct health costs associated with pertussis cases reported to and confirmed by epidemiological services and cases detected among household contacts in Catalonia (Spain) in 2012-2013. METHODS: All pertussis cases confirmed by the epidemiological services (n = 641) and all cases detected among the household contacts (n = 422) were included in the study. The chi-square test and odds ratios were used to compare percentages and the t-test was used to compare mean pertussis costs, with p < 0.05 being considered statistically significant. RESULTS: Cases reported to epidemiological services had a higher percentage of hospitalizations (OR = 32.2, p < 0.001) and severe disease (OR = 27.7, p < 0.001) than cases detected among the household contacts. The total health costs associated with pertussis cases were €871,648, €799,704 (92 %) for cases reported to epidemiological services and €71,944 (8 %) for cases detected among the household contacts. Total treatment, detection, and quimiprophylaxis costs were € 809,702, € 44,312, and € 17,635, representing 92.5 %, 5.5 %, and 2 % of total pertussis costs respectively. The mean costs were significantly higher (p < 0.001) in cases reported to epidemiological services than in cases detected among the household contacts, for all cases (€1248 vs €170), and for severe (€4546 vs €1073), moderate (€204 vs €165), and mild (€153 vs €133) disease. CONCLUSIONS: The burden of pertussis in Catalonia was high in terms of health costs, especially in infants aged less than 1 year. Active epidemiological surveillance activities could prevent pertussis transmisison and reduce pertussis costs.

Burden and Outcomes of Severe Pertussis Infection in Critically Ill Infants.

OBJECTIVES: Despite World Health Organization endorsed immunization schedules, Bordetella pertussis continues to cause severe infections, predominantly in infants. There is a lack of data on the frequency and outcome of severe pertussis infections in infants requiring ICU admission. We aimed to describe admission rates, severity, mortality, and costs of pertussis infections in critically ill infants. DESIGN: Binational observational multicenter study. SETTING: Ten PICUs and 19 general ICUs in Australia and New Zealand contributing to the Australian and New Zealand Paediatric Intensive Care Registry. PATIENTS: Infants below 1 year of age, requiring intensive care due to pertussis infection in Australia and New Zealand between 2002 and 2014. MEASUREMENTS AND MAIN RESULTS: During the study period, 416 of 42,958 (1.0%) infants admitted to the ICU were diagnosed with pertussis. The estimated population-based ICU admission rate due to pertussis ranged from 2.1/100,000 infants to 18.6/100,000 infants. Admission rates were the highest among infants less than 60 days old (p < 0.0001). Two hundred six infants (49.5%) required mechanical ventilation, including 20 (4.8%) treated with high-frequency oscillatory ventilation, 16 (3.8%) with inhaled nitric oxide, and 7 (1.7%) with extracorporeal membrane oxygenation. Twenty of the 416 children (4.8%) died. The need for mechanical ventilation, high-frequency oscillatory ventilation, nitric oxide, and extracorporeal membrane oxygenation were significantly associated with mortality (p < 0.01). Direct severe pertussis-related hospitalization costs were in excess of USD$1,000,000 per year. CONCLUSIONS: Pertussis continues to cause significant morbidity and mortality in infants, in particular during the first months of life. Improved strategies are required to reduce the significant healthcare costs and disease burden of this vaccine-preventable disease.

Modelling the return on investment of preventively vaccinating healthcare workers against pertussis.

BACKGROUND: Healthcare workers (HCWs) are at particular risk of acquiring pertussis and transmitting the infection to high-risk susceptible patients and colleagues. In this paper, the return on investment (ROI) of preventively vaccinating HCWs against pertussis to prevent nosocomial pertussis outbreaks is estimated using a hospital ward perspective, presuming an outbreak occurs once in 10 years. METHODS: Data on the pertussis outbreak on the neonatology ward in 2004 in the Academic Medical Center Amsterdam (The Netherlands) was used to calculate control costs and other outbreak related costs. The study population was: neonatology ward staff members (n = 133), parents (n = 40), neonates (n = 20), and newborns transferred to other hospitals (n = 23). ROI is presented as the amount of Euros saved in averting outbreaks by investing one Euro in preventively vaccinating HCWs. Sensitivity analysis was performed to study the robustness of the ROI. Results are presented at 2012 price level. RESULTS: Total nosocomial pertussis outbreak costs were €48,682. Direct control costs (i.e. antibiotic therapy, laboratory investigation and outbreak management control) were €11,464. Other outbreak related costs (i.e. sick leave of HCWs; restrictions on the neonatology ward, savings due to reduced working force required) accounted for €37,218. Vaccination costs were estimated at €12,208. The ROI of preventively vaccinating HCWs against pertussis was 1:4, meaning 4 Euros could be saved by every Euro invested in vaccinating HCWs to avert outbreaks. ROI was sensitive to a lower vaccine price, considering direct control costs only, average length of stay of neonates on the neonatology ward, length of patient uptake restrictions, assuming no reduced work force due to ward closer and presuming more than one outbreak to occur in 10 years' time. CONCLUSION: From a hospital ward perspective, preventive vaccination of HCWs against pertussis to prevent nosocomial pertussis outbreaks results in a positive ROI, presuming an outbreak occurs once in 10 years.

Pertussis immunisation in pregnancy: a summary of funded Australian state and territory programs.

The Australian Immunisation Handbook, 10th edition now recommends pertussis vaccination during pregnancy as the preferred option for protecting vulnerable young infants. Jurisdictionally funded pertussis immunisation programs for pregnant women have been progressively introduced in all Australian states and territories between August 2014 and June 2015. A meeting convened by the National Centre for Immunisation Research and Surveillance of Vaccine Preventable Diseases was held on 31 May 2015 to share information regarding jurisdictional policies and program implementation. This report of that meeting provides the first published comparison of these jurisdictional programs, which are of a broadly similar nature but with important differences. Monitoring and evaluation of the uptake, safety and impact of the current programs in Australia will be important to inform future policy decisions.

Estimated Human and Economic Burden of Four Major Adult Vaccine-Preventable Diseases in the United States, 2013.

Low uptake of routinely recommended adult immunizations is a public health concern. Using data from the peer-reviewed literature, government disease-surveillance programs, and the US Census, we developed a customizable model to estimate human and economic burden caused by four major adult vaccine-preventable diseases (VPD) in 2013 in the United States, and for each US state individually. To estimate the number of cases for each adult VPD for a given population, we multiplied age-specific incidence rates obtained from the literature by age-specific 2013 Census population data. We then multiplied the estimated number of cases for a given population by age-specific, estimated medical and indirect (non-medical) costs per case. Adult VPDs examined were: (1) influenza, (2) pneumococcal disease (both invasive disease and pneumonia), (3) herpes zoster (shingles), and (4) pertussis (whooping cough). Sensitivity analyses simulated the impact of various epidemiological scenarios on the total estimated economic burden. Estimated US annual cost for the four adult VPDs was $26.5 billion (B) among adults aged 50 years and older, $15.3B (58 %) of which was attributable to those 65 and older. Among adults 50 and older, influenza, pneumococcal disease, herpes zoster, and pertussis made up $16.0B (60 %), $5.1B (19 %), $5.0B (19 %), and $0.4B (2 %) of the cost, respectively. Among those 65 and older, they made up $8.3B (54 %), $3.8B (25 %), $3.0B (20 %), and 0.2B (1 %) of the cost, respectively. Most (80-85 %) pneumococcal costs stemmed from nonbacteremic pneumococcal pneumonia (NPP). Cost attributable to adult VPD in the United States is substantial. Broadening adult immunization efforts beyond influenza only may help reduce the economic burden of adult VPD, and a pneumococcal vaccination effort, primarily focused on reducing NPP, may constitute a logical starting place. Sensitivity analyses revealed that a pandemic influenza season or change in size of the US elderly population could increase these costs dramatically.

[Hospitalization due to whooping cough in Spain (1997-2011)]. / Hospitalización por tos ferina en España (1997-2011).

INTRODUCTION: Pertussis incidence has increased in recent years in countries with high vaccination coverage. The aim of this study was to determine the health impact of pertussis in Spain in the period 1997-2011 in relation to hospitalizations, mortality, and associated costs. METHODS: We retrospectively analyzed hospital discharges included in the Minimum Data Set (MDS) in Spain for the period 1997-2011, with a primary or secondary diagnosis related to pertussis. We calculated incidence rates of hospitalization for pertussis (per 100,000) per year, by age group and by Autonomous Region, along with the mortality and lethality rates. RESULTS: A total of 8,331 hospital discharges with a diagnosis of pertussis were recorded in Spain between 1997 and 2011. The overall incidence of pertussis hospitalizations was 1.3 cases per 100,000 inhabitants. The large majority (92%) of hospitalizations occurred in children under one year of age, with an incidence of 115.2 hospitalizations per 100,000. There were 47 deaths, 37 (79%) in the group of children under 1 year and 6 (13%) in the group older than 65 years. The estimated cost of hospitalization for pertussis was 1,841 euros. CONCLUSION: The epidemiology of severe cases of pertussis, and its clinical and economic impact, confirms the need to modify the vaccination strategies for Spain to achieve more effective control in the most vulnerable groups.

Pertussis in young infants: clinical presentation, course and prevention.

Pertussis is a highly contagious disease caused by the Gram negative aerobic coccobacillus, Bordetella pertussis. It may present with severe symptoms and complications in infants and can pose a diagnostic challenge. This is a vaccine preventable illness covered by the Irish Childhood Immunisation Schedule. In 2011, a retrospective review was conducted of the records of infants, under six months, with a confirmed diagnosis of pertussis, presenting to Temple Street Children's University Hospital (TSCUH). A summery of notifications of pertussis nationally, from 2001 to 2012, was also examined as part of the study. This found that the rate of reported cases of pertussis has been increasing in Ireland. This national increase corresponds with a rising number of cases identified at TSCUH. Patients commonly presented severely ill with cyanosis and apnoea, on a background of prolonged cough. We found that pertussis was diagnosed rapidly in most cases however in all cases there was a delay to commencement of appropriate macrolide therapy.

Economic burden of pertussis in children: A single-center analysis in Hangzhou, China.

The "reemergence of pertussis" has elicited international concerns, occurring paradoxically amidst the expansion of immunization programs. This study was aimed to evaluate quantitatively the economic burden and identify the determinants that influence the cost associated with treating pertussis in Chinese children. We evaluated the economic burden by Chinese children diagnosed with pertussis at the Children's Hospital, Zhejiang University School of Medicine in 2022. Direct medical expenses and the utilization of medical resources attributed to pertussis were calculated. A generalized linear regression model was applied to analyze the determinants that were associated with the direct medical expenses among patients. Among the 1110 pertussis patients included in the study, 1060 were outpatients and 50 were inpatients. The average direct medical cost was ¥1878.70(i.e. $279.33). Living in urban areas (OR:1.27, p = .04), complications (OR:1.40, p < .001), hospitalization (OR:10.04, p < .001), and ≥ 3 medical visits (OR:3.71, p < .001) were associated with increased direct medical expenses. Having received four doses of the pertussis vaccine was associated with reduced direct medical expenses (OR:0.81, p = .04). This study underscores a substantial economic burden of pertussis in Hangzhou, with pronounced implications for patients residing in urban areas, experiencing complications, requiring hospitalization, having multiple medical consultations, or lacking comprehensive pertussis vaccination.

Evaluation of pre-school pertussis booster vaccination in Shanghai, China: A cost-effectiveness analysis.

BACKGROUND: In recent years, notified pertussis cases have been increasingly documented in China. It raised a new public health concern of potential optimization in immunization strategy. This study was aimed to determine the cost-effectiveness of different immunization strategies against pertussis-containing vaccines for 6-year-old pre-school children in Shanghai. METHODS: A Markov-decision tree model was applied to evaluate two pertussis immunization strategies for 6-year-old pre-school children as following: (1) 1 dose of acellular pertussis (aP) contained vaccine (DTaP or Tdap) booster vaccinated at 6 years of age, and (2) no booster at 6 years of age regimen. Primary outcomes included quality-adjusted life years (QALYs), costs, and incremental cost-utility ratios (ICUR). Sensitivity analyses were performed. The analysis was conducted over a study period of 14 years from a societal perspective. RESULTS: Compared to no booster immunization strategy, administering 1 dose of acellular pertussis (aP) contained vaccine (DTaP or Tdap) booster at 6 years of age, resulted in an average cost reduction of CNY 814.16 (USD 116) per individual, an increase in QALYs by 0.00066, and a rise in per capita net monetary benefit (NMB) by CNY 933.51 (USD 132). The total costs over the study period were reduced by CNY 160.59 million (USD 23 million), utility increased by 130.49 QALYs, and NMB increased by CNY 184.14 million (USD 26 million). CONCLUSIONS: Implementing acellular pertussis booster immunization for 6-year-old pre-school children in Shanghai emerges as a cost-saving immunization strategy, with both cost savings and utility gains.

The disease burden of pertussis in adults 50 years old and older in the United States: a retrospective study.

BACKGROUND: While the incidence of pertussis has increased in adolescents and adults in recent years in the U.S., little is known about the incidence and economic burden of pertussis in older adults. This study provides evidence of the incidence of pertussis and direct medical charges associated with pertussis episodes of care (PEOCs) in adults aged 50 years and older in the U.S. METHODS: PEOCs were divided into periods before and after the initial pertussis diagnosis was made (i.e., the index date) to capture any conditions immediately preceding the pertussis diagnosis that may have represented misdiagnoses and subsequent conditions that may have represented sequelae. Data were extracted from IMS's recently acquired SDI databases of longitudinal, patient-level practitioner claims and hospital operational billing records collected from private practitioners and hospitals, respectively, across the U.S. Patients 50 years and older with one or more ICD-9-CM diagnoses for pertussis/whooping cough and/or a laboratory test positive for Bordetella pertussis between 1/1/2006 and 10/31/2010 were eligible for study inclusion. Resource utilization and charges (i.e., unadjudicated claims) associated with the patient's physician and hospital care were analyzed. The nationally projected incidence of pertussis was estimated using a subsample of patients with the required data necessary for projection. RESULTS: Estimated incidence of diagnosed pertussis ranged from 2.1-4.6 cases per 100,000 people across the two age groups (50-64 and [greater than or equal to] 65) during the years 2006 to 2010. The analysis of charges included 5,748 patients [greater than or equal to] 50 years of age with pertussis. Average charges across the entire episode of care were $1,835 and $14,428 per patient in the outpatient and inpatient settings, respectively. The average number of outpatient (i.e., private practitioner) visits was 2 per patient in both the pre-index and post-index periods. CONCLUSIONS: In the U.S., the incidence of diagnosed pertussis in adults 50 years and older has increased between 2006 and 2010. Healthcare utilization and charges associated with pertussis are substantial, suggesting the need for additional prevention and control strategies and a higher degree of clinical awareness on the part of health care providers. Additional research regarding pertussis in older populations is needed to substantiate these findings.

Local health department costs associated with response to a school-based pertussis outbreak --- Omaha, Nebraska, September-November 2008.

Pertussis is a highly infectious, vaccine-preventable respiratory illness. With the advent of a vaccine, case numbers fell in the United States from a high of 265,269 in 1934 to a low of 1,010 cases in 1976, but then resurged to 25,827 in 2004. During 2004-2008, the average was 18,161 cases per year. Close contacts of persons with pertussis are at increased risk for developing infection and are recommended to receive preventive antibiotics for two reasons: 1) the illness can be debilitating, with cough lasting several weeks and sometimes being severe enough to cause urinary incontinence, rib fracture, or other complications; and 2) the illness can be fatal in infants; it caused an average of 17 deaths each year during 2002-2006. During pertussis outbreaks, the resources needed to identify and treat contacts can strain local public health resources. The Douglas County Health Department (DCHD) in Omaha, Nebraska, responded to a school-based pertussis outbreak with 26 cases occurring in late 2008. To assess the costs incurred by a local health department responding to such an outbreak, DCHD and CDC evaluated the total resources used by DCHD. This report describes the results of that analysis, which indicated that 1) staff members reported 1,032 person-hours spent responding to the outbreak, and 2) the total cost of outbreak response, including overhead, labor, travel, and other costs, was $52,131 (measured in 2008 U.S. dollars). The majority of costs (59%) occurred during an intensive 10-day period, when most of the contact tracing and prophylaxis recommendations were made. The elevated incidence of pertussis and the burden of response placed on health departments warrants exploring the impact of alternative response and chemoprophylaxis strategies.

The distribution over time of costs and social net benefits for pertussis immunization programs.

The cost of a six-dose pertussis immunization programs for children and adolescents is investigated in relation to estimators of the price of acellular vaccine, the value of a child's life, levels of vaccination rate and discount rates. We compare the cost of the program maintained over time at 90% with three alternative strategies, each involving a decrease in vaccination coverage. Data from England and Wales, 1966-2005, is used to formalize a delay in occurrence of pertussis cases as a result of a fall in coverage. We first apply the criterion of minimization of the total social cost of pertussis to identify the best cost saving immunization strategy. The results are also discussed in form of the discounted present value of the total social net benefits. We find that the discounted present value of the total social net benefit is maximized when a stable vaccination program at 90% is compared to a gradual decrease in vaccination coverage leading to the lowest vaccination rate. The benefits to society of providing sustained immunization strategy, vaccinating the highest proportion of children and adolescents, are systematically proved on the basis of the second optimisation criterion, independently of the level of estimators applied during economic evaluation for the cost variables.

Pertussis vaccination for health care workers.

Pertussis, an acute respiratory infection caused by Bordetella pertussis, classically manifests as a protracted cough illness. The incidence of pertussis in the United States has been increasing in recent years. Immunity wanes after childhood vaccination, leaving adolescents and adults susceptible to infection. The transmission of pertussis in health care settings has important medical and economic consequences. Acellular pertussis booster vaccines are now available for use and have been recommended for all adolescents and adults. These vaccines are safe, immunogenic, and effective. Health care workers are a priority group for vaccination because of their increased risk of acquiring infection and the potential to transmit pertussis to high-risk patients. Health care worker vaccination programs are likely to be cost-effective, but further research is needed to determine the acceptability of pertussis vaccines among health care workers, the duration of immunity after booster doses, and the impact of vaccination on the management of pertussis exposures in health care settings.

Pertussis vaccination in mixed markets: Recommendations from the Global Pertussis Initiative.

The Global Pertussis Initiative is an expert scientific forum that publishes consensus recommendations concerning pertussis for many regions of the world. Here, we give recommendations for the primary vaccination of infants in those countries where whole-cell pertussis (wP)- and acellular pertussis (aP)-containing combination vaccines are used in parallel. A selective literature review was performed concerning the influence on safety, immunogenicity, and effectiveness of mixing wP- and aP-containing vaccines for primary immunization of infants. In addition, local data were collected from various countries and the results discussed in a face-to-face meeting. Very few data addressing issues of mixing combination vaccines were identified, and no data were available concerning the effectiveness or duration of protection. It was also found that pharmacovigilance data are scarce or lacking in those countries where they would be needed the most. We then identified frequent problems occurring in low- and middle-income countries (LMICs) where both vaccine types are used. Relying on local knowledge, we give practical recommendations for a variety of situations in different settings. Specific needs for additional data addressing these issues were also identified. International bodies, such as the World Health Organization (WHO), as well as vaccine producers should try to find ways to highlight the problems of mixing wP- and aP-containing combination vaccines with robust data. Countries are urged to improve on their pharmacovigilance for vaccines. For practicing physicians, our recommendations offer guidance when wP- and aP-containing vaccines are used in parallel during primary immunization.

Epidemiology and disease burden of pertussis in the United States among individuals aged 0-64 over a 10-year period (2006-2015).

Background: Pertussis incidence has increased in recent decades despite childhood vaccination programs and high vaccination rates. To quantify the burden of pertussis, incidence, healthcare resource utilization, and costs among pertussis patients were estimated in a US managed care setting.Methods: Patients aged 0-64 years with evidence of pertussis (ICD-9-CM codes 033.0, 033.9, 484.3, ICD-10-CM codes A37.0, A37.9) and commercial insurance from 1 January 2006-12 December 2015 were identified. Incidence rates were calculated and standardized to the 2010 US Census on age, sex, and geographic region. Healthcare costs and resource utilization were compared between patients and matched comparators (health plan members without pertussis).Results: From 2006 to 2015, 11,378 pertussis cases were identified. Adjusted pertussis incidence was 15.55 cases per 100,000 person-years. Incidence was highest among infants and children; however, 59.0% of total cases were among adolescents or adults. Average adjusted healthcare costs per episode were 3.17 times higher among pertussis patients versus comparators ($5195 versus $1637, p < .001). Stratifying by age group, adjusted incremental healthcare costs per episode were $5581, $827, $700, $1429, $2530, and $4849 for patients aged <1 year, 1-6 years, 7-10 years, 11-19 years, 20-49 years, and 50-64 years, respectively.Conclusions: Managing pertussis is associated with substantial economic burden. Incidence rate estimates from this study were higher than CDC-reported rates; however, similar overall trends were observed. Although pertussis incidence has been declining since CDC-recommended vaccination for all adults in 2012, this study highlights the importance of continued management and prevention strategies, especially among adolescents and adults as they represent an important source of transmission to infants.

Economic impact of implementing decennial tetanus toxoid, reduced diphtheria toxoid and acellular pertussis (Tdap) vaccination in adults in the United States.

BACKGROUND: In the United States, persons ≥11 years are recommended to receive one dose of tetanus toxoid, reduced diphtheria toxoid and acellular pertussis (Tdap) vaccine, followed by decennial tetanus- and diphtheria-toxoid (Td) boosters. Many providers use Tdap instead of Td. We evaluated epidemiologic and economic impacts of replacing Td boosters with Tdap. METHODS: We used a static cohort model to examine replacing Td with Tdap over the lifetime of 4,386,854 adults ≥21 years. Because pertussis is underdiagnosed and true incidence is unknown, we varied incidence from 2.5 cases/100,000 person-years to 500 cases/100,000 person-years. We calculated vaccine and medical costs from claims data. We estimated cost per case prevented and per quality-adjusted life year (QALY) saved; sensitivity analyses were conducted on vaccine effectiveness (VE), protection duration, vaccine cost, disease duration, hospitalization rates, productivity loss and missed work. We did not include programmatic advantages resulting from use of a single tetanus-toxoid containing vaccine. RESULTS: At lowest incidence estimates, administering Tdap resulted in high costs per averted case ($111,540) and QALY saved ($8,972,848). As incidence increased, cases averted increased and cost per QALY saved decreased rapidly. With incidence estimates of 250 cases/100,000 person-years, cost per averted case and QALY saved were $984 and $81,678 respectively; at 500 cases/100,000 person-years, these values were $427 and $35,474. In multivariate sensitivity analyses, assuming 250 cases/100,000 person-years, estimated cost per QALY saved ranged from $971 (most favorable) to $217,370 (least favorable). CONCLUSIONS: Our findings suggest that replacing Td with Tdap for the decennial booster would result in high cost per QALY saved based on reported cases. However, programmatic considerations were not accounted for, and if pertussis incidence, which is incompletely measured, is assumed to be higher than reported through national surveillance, substituting Tdap for Td may lead to moderate decreases in pertussis cases and cost per QALY.

The burden of pertussis in older adults: what is the role of vaccination? A systematic literature review.

INTRODUCTION: Pertussis (whooping cough) is a vaccine-preventable disease; however, neither natural- nor vaccine-induced protection is life-long. Although generally not severe in adults, pertussis can be associated with complications in patients with chronic conditions such as asthma or chronic obstructive pulmonary disease, and can be readily transmitted to more vulnerable populations, including neonates before they complete their primary vaccination. Furthermore, as the global population ages, the health and economic burden of the disease is expected to rise. Areas covered: A systematic literature review was conducted to ascertain the current epidemiological and financial burden of pertussis in older adults and to discuss the potential value of a booster vaccination in this population. Expert commentary: Our review indicates a considerable underestimation of the pertussis burden amongst older adults. Seroprevalence studies consistently demonstrate that the reported incidence may be much lower than the actual incidence. Tetanus toxoid-reduced diphtheria toxoid and acellular pertussis vaccines are immunogenic in older adults, induce high booster responses and are well-tolerated. There is therefore a good rationale for the advocacy of booster pertussis vaccination throughout life to prevent pertussis infection and its transmission, especially in adults aged ≥50 years.

The health and economic burden of pertussis in Canada: A microsimulation study.

BACKGROUND: Despite excellent vaccine coverage, pertussis persists in Canada, with high incidence during recent outbreaks and non-negligible incidence in non-outbreak years. While Canadian pertussis incidence is well-characterized, the full health and economic impact of pertussis have not been examined in Canada. We estimated age-specific life years (LYs) and quality-adjusted life years (QALYs) lost, and costs due to pertussis in Ontario, Canada, using a model-based approach. METHODS: We developed a microsimulation model to simulate pertussis natural history. Daily probabilities of pertussis complications, hospitalizations, and disease sequelae as well as utilities and costs for health states were literature-derived. A healthcare payer perspective was used with a lifetime time horizon. Model outcomes were compared to those from a model with no pertussis health states. Probabilistic sensitivity analyses were used to generate distributions for estimates. Economic burden was estimated by multiplying case cost estimates by annual age-specific incidence. RESULTS: Overall, LYs lost per pertussis case was low, with negligible LYs lost in those aged >4 years. Infants (<6 months) had the greatest mean QALY loss per case (0.58), while adults lost only 0.05 QALYs per case. Infants experienced the greatest mean cost per case of $22,768 (95% CI: 21,144-23,406). Case costs generally declined with age, but increased in seniors (aged 65+) with mean cost of $1920 (95% CI: 1800-2033). Based on historic age-specific incidence, pertussis costs the Ontario healthcare system approximately $7.6-$21.5 M annually. In total economic cost estimates with QALYs valued at 1xGDP (3xGDP) per capita, the net impact of pertussis in Ontario was estimated at $21.7-$66.5 M annually ($50.0-$156.3 M). For all of Canada, total economic costs were estimated at $79.6-$241.3 M ($187.5-$580.5 M) annually. CONCLUSION: The health and economic consequences of pertussis persistence are substantial and highlight the need for improved control strategies.

Trends and costs of pertussis hospitalizations in Portugal, 2000 to 2015: from 0 to 95 years old.

BACKGROUND: Pertussis has caused several outbreaks and concern worldwide. Despite high vaccination coverage, people of all ages are still affected with significant morbidity and mortality. We aimed to analyse all pertussis hospitalizations in Portugal to help to delineate preventive policies. METHODS: Data were collected from a Portuguese administrative database, which contains all registered hospitalizations in mainland Portugal. Cases were identified using the ICD-9-CM code 033.x (whooping cough) as principal or secondary diagnosis, with hospital discharges between 2000 and 2015. Data were analysed by age groups. RESULTS: Of 2281 hospitalizations, 94% occurred in infants (<1 year). The mean and median ages were 20 and 2 months, respectively. A seasonal pattern was observed, with higher number of hospitalizations during the winter for infants, and during the summer for other age groups. Higher hospitalization rates were registered in the Southern regions. The mean and median lengths of hospital stay were 8 and 6 days, respectively. The main complications were acute respiratory failure and pneumonia. Invasive or non-invasive ventilation, or both, was required in 2.4, 1.8 and 0.6% of hospitalized cases, respectively. The overall inpatient case fatality rate was 0.7%; 0.8, 11.5 and 17.4% for the age groups 0-1 months, 18-64 years and ≥65 years, respectively. Total hospitalization costs were estimated to be 2,698,995€. CONCLUSION: Our study emphasizes the need to adopt new preventive strategies mainly focused on infants, to reduce morbidity and costs of hospitalizations related to pertussis.