A framework for assessing the lifetime economic burden of congenital cytomegalovirus in the United States

Vaccine value profile for cytomegalovirus

Cytomegalovirus (CMV) is the most common infectious cause of congenital malformation and a leading cause of developmental disabilities such as sensorineural hearing loss (SNHL), motor and cognitive deficits. The significant disease burden from congenital CMV infection (cCMV) led the US National Institute of Medicine to rank CMV vaccine development as the highest priority. An average of 6.7/1000 live births are affected by cCMV, but the prevalence varies across and within countries. In contrast to other congenital infections such as rubella and toxoplasmosis, the prevalence of cCMV increases with CMV seroprevalence rates in the population. The true global burden of cCMV disease is likely underestimated because most infected infants (85-90 %) have asymptomatic infection and are not identified. However, about 7-11 % of those with asymptomatic infection will develop SNHL throughout early childhood. Although no licensed CMV vaccine exists, several candidate vaccines are in development, including one currently in phase 3 trials. Licensure of one or more vaccine candidates is feasible within the next five years. Various models of CMV vaccine strategies employing different target populations have shown to provide substantial benefit in reducing cCMV. Although CMV can cause end-organ disease with significant morbidity and mortality in immunocompromised individuals, the focus of this vaccine value profile (VVP) is on preventing or reducing the cCMV disease burden. This CMV VVP provides a high-level, comprehensive assessment of the currently available data to inform the potential public health, economic, and societal value of CMV vaccines. The CMV VVP was developed by a working group of subject matter experts from academia, public health groups, policy organizations, and non-profit organizations. All contributors have extensive expertise on various elements of the CMV VVP and have described the state of knowledge and identified the current gaps. The VVP was developed using only existing and publicly available information.

Re-Evaluating Human Cytomegalovirus Vaccine Design: Prediction of T Cell Epitopes

HCMV vaccine development has traditionally focused on viral antigens identified as key targets of neutralizing antibody (NAb) and/or T cell responses in healthy adults with chronic HCMV infection, such as glycoprotein B (gB), the glycoprotein H-anchored pentamer complex (PC), and the unique long 83 (UL83)-encoded phosphoprotein 65 (pp65). However, the protracted absence of a licensed HCMV vaccine that reduces the risk of infection in pregnancy regardless of serostatus warrants a systematic reassessment of assumptions informing vaccine design. To illustrate this imperative, we considered the hypothesis that HCMV proteins infrequently detected as targets of T cell responses may contain important vaccine antigens. Using an extant dataset from a T cell profiling study, we tested whether HCMV proteins recognized by only a small minority of participants encompass any T cell epitopes. Our analyses demonstrate a prominent skewing of T cell responses away from most viral proteins-although they contain robust predicted CD8 T cell epitopes-in favor of a more restricted set of proteins. Our findings raise the possibility that HCMV may benefit from evading the T cell recognition of certain key proteins and that, contrary to current vaccine design approaches, including them as vaccine antigens could effectively take advantage of this vulnerability.

A systematic literature review of the economic and healthcare resource burden of cytomegalovirus

OBJECTIVE

Cytomegalovirus (CMV) can infect individuals at any age, including infants, who may contract it from infected mothers (congenital CMV [cCMV]). Whereas CMV infection is typically asymptomatic or causes mild illness in healthy individuals, infection can result in severe outcomes in immunocompromised individuals and in infants with cCMV. This systematic review aims to characterize the economic impact of CMV and cCMV infections.

METHODS

Medline, Embase, and LILACS databases were searched for publications reporting the economic impact of cCMV and CMV infections across all age groups. Manuscripts published between 2010 and 2020 from Australia, Latin America, Canada, Europe, Israel, Japan, the United States, and global (international, worldwide) studies were included; congress materials were excluded. Outcomes of interest included cCMV- and CMV-attributable direct costs/charges, resource utilization, and indirect/societal costs.

RESULTS

Of 751 records identified, 518 were excluded based on duplication, population, outcome, study design, or country. Overall, 55 articles were eligible for full-text review; 25 were further excluded due to population, outcome, study design, or congress abstract. Two publications were additionally identified, resulting in economic impact data compiled from 32 publications. Of these, 24 publications reported cost studies of cCMV or CMV, including evaluation of direct costs/charges, healthcare resource utilization, and indirect/societal costs, and 7 publications reported economic evaluations of interventions. The populations, methods and outcomes used across these studies varied widely.

CONCLUSIONS

CMV and cCMV infections impose a considerable economic impact on different countries, populations, and outcomes. There are substantial evidence gaps where further research is warranted.

Healthcare costs of congenital cytomegalovirus (cCMV) disease in infants during the first two years of life: a retrospective German claims database analysis

BACKGROUND

Congenital cytomegalovirus (cCMV) infection can cause severe neurological damage, growth retardation, hearing loss, and microcephaly in infants. We aimed at assessing healthcare costs of infants with recorded cCMV diagnosis in an administrative claims database in the first 2 years of life.

METHODS

We conducted a retrospective, controlled cohort study using German claims data from the Institute for Applied Health Research Berlin (InGef) database. Incremental healthcare costs during the first and second year of life were assessed by matching (1:60) infants with cCMV diagnoses ≤ 90 days after birth (cCMV₉₀ cohort) to infants without cCMV diagnosis ("representative" controls) and infants with cCMV diagnoses ≤ 21 days after birth plus specific symptoms (cCMV_21-S) to infants without cCMV and any ICD-10-GM records (besides Z00-Z99) until 4^th preventive health check-up ("healthy" controls). Due to missing data, mean imputation was applied for aids and remedies costs.

RESULTS

We identified 54 and 24 infants born 2014-2018 for the cCMV₉₀ and cCMV_21-S cohorts, respectively. During the first year, mean (median) healthcare costs were significantly higher in cCMV₉₀ cases vs. "representative" controls (€22,737 (€9759) vs. €3091 (€863), p < 0.001), with 87.2% inpatient costs. Healthcare costs for cCMV_21-S cases compared to "healthy" controls were €34,498 (€20,924) vs. €680 (€569), p < 0.001. Differences decreased for both comparisons in the second year but remained statistically significant.

CONCLUSIONS

cCMV comprises a considerable economic burden for the German healthcare system (€19,646 to €33,818 higher mean costs for infants with recorded cCMV diagnosis in the first year of life). Attempts should be made to reduce this burden.

Universal First-Trimester Cytomegalovirus Screening and Valaciclovir Prophylaxis in Pregnant Persons: A Cost-Effectiveness Analysis

BACKGROUND

Recent studies suggest a possible benefit of valaciclovir prophylaxis to prevent vertical transmission after a positive serologic screen for primary maternal cytomegalovirus infection during pregnancy, although its cost-effectiveness remains uncertain.

OBJECTIVE

We sought to determine the circumstances under which universal first-trimester maternal serologic screening for maternal cytomegalovirus infection, with valaciclovir prophylaxis to prevent congenital cytomegalovirus, is cost-effective.

STUDY DESIGN

We performed a decision analysis from the perspective of the pregnant person to assess whether universal maternal screening in the first trimester, with subsequent valaciclovir prophylaxis (8g/day from time of positive serologic screen for primary maternal cytomegalovirus infection through 21 weeks' gestation) for those who are acutely infected, is cost-effective compared to usual care (i.e., no routine serologic screening, but amniocentesis if mid-trimester sonographic findings suggest cytomegalovirus). For baseline estimates, we assumed a 35% risk of congenital cytomegalovirus after primary maternal infection and a 71% risk reduction with valaciclovir. We varied valaciclovir's efficacy to identify whether and at what threshold universal screening would be estimated to be cost-effective, compared to usual care. Monte Carlo analyses were performed. A willingness-to-pay threshold of $100,000/quality-adjusted life year was used to define cost-effectiveness.

RESULTS

Under base-case estimates, first-trimester universal screening and valaciclovir prophylaxis for seropositive pregnant persons with acute cytomegalovirus infection is not cost-effective, with a cost of $137,854 per maternal QALY, but results in 14 fewer cytomegalovirus-affected children per 100,000 pregnancies compared to usual care. In one-way sensitivity analysis, universal screening and treatment is estimated to be the cost-effective strategy if the incidence of primary maternal cytomegalovirus infection exceeds 2.6%, baseline risk of vertical transmission of cytomegalovirus without prophylaxis is greater than 36.8%, and the risk reduction of vertical transmission of cytomegalovirus with valaciclovir prophylaxis exceeds 75.9%. In Monte Carlo analyses, first-trimester universal serologic screening with valaciclovir prophylaxis is estimated to be the cost-effective strategy in 46.8% of runs.

CONCLUSION

Universal first-trimester serologic screening with valaciclovir prophylaxis is not the cost-effective strategy for antenatal management of cytomegalovirus under the base-case estimates. Although universal screening is cost-effective in certain circumstances when the efficacy of valaciclovir exceeds the base case, that result is not robust to variation of estimates across their reasonable ranges. These data can inform future studies to evaluate screening and treatment to prevent congenital CMV.

Identification of congenital CMV cases in administrative databases and implications for monitoring prevalence, healthcare utilization, and costs

OBJECTIVE

To critically review researchers' use of diagnosis codes to identify congenital cytomegalovirus (cCMV) infection or disease in healthcare administrative databases. Understanding the limitations of cCMV ascertainment in those databases can inform cCMV surveillance and health services research.

METHODS

We identified published studies that used diagnosis codes for cCMV or CMV in hospital discharge or health insurance claims and encounters records for infants to assess prevalence, use of services, or healthcare costs. We reviewed estimates of prevalence and of charges, costs, or expenditures associated with cCMV diagnosis codes.

RESULTS

Five studies assessed hospitalizations with cCMV diagnosis codes recorded in hospital discharge databases, from the United States (n = 3), Australia (n = 1), and the United Kingdom (n = 1). Six other studies analyzed claims or encounters data from the United States (n = 5) or Japan (n = 1) to identify infants with cCMV codes. Prevalence estimates of recognized cCMV ranged from 0.6 to 3.8 per 10,000 infants. Economic analyses reported a wide range of per-hospitalization or per-infant cost estimates, which lacked standardization or comparability.

CONCLUSIONS

The administrative prevalence of cCMV cases reported in published analyses of administrative data from North America, Western Europe, Japan, and Australia (0.6-3.8 per 10,000 infants) is an order of magnitude lower than the estimates of the true birth prevalence of 3-7 per 1,000 newborns based on universal newborn screening pilot studies conducted in the same regions. Nonetheless, in the absence of systematic surveillance for cCMV, administrative data might be useful for assessing trends in testing and clinical diagnosis. To the extent that cCMV cases recorded in administrative databases are not representative of the full spectrum of cCMV infection or disease, per-child cost estimates generated from those data may not be generalizable. On the other hand, claims data may be useful for estimating patterns of healthcare use and expenditures associated with combinations of diagnoses for cCMV and known complications of cCMV.