A comparative cost analysis of the Vaccination Program for US-bound Refugees

BackgroundVaccination Program for US-bound Refugees (VPR) currently provides one or two doses of some age-specific Advisory Committee on Immunization Practices (ACIP)-recommended vaccines to US-bound refugees prior to departure.MethodsWe quantified and compared the full vaccination costs for refugees using two scenarios: (1) the baseline of no VPR and (2) the current situation with VPR. Under the first scenario, refugees would be fully vaccinated after arrival in the United States. For the second scenario, refugees would receive one or two doses of selected vaccines before departure and complete the recommended vaccination schedule after arrival in the United States. We evaluated costs for the full vaccination schedule and for the subset of vaccines provided by VPR by four age-stratified groups; all costs were reported in 2015 US dollars. We performed one-way and probabilistic sensitivity analyses and break-even analyses to evaluate the robustness of results.ResultsVaccination costs with the VPR scenario were lower than costs of the scenario without the VPR for refugees in all examined age groups. Net cost savings per person associated with the VPR were ranged from $225.93 with estimated Refugee Medical Assistance (RMA) or Medicaid payments for domestic costs to $498.42 with estimated private sector payments. Limiting the analyses to only the vaccines included in VPR, the average costs per person were 56% less for the VPR scenario with RMA/Medicaid payments. Net cost savings with the VPR scenario were sensitive to inputs for vaccination costs, domestic vaccine coverage rates, and revaccination rates, but the VPR scenario was cost savings across a range of plausible parameter estimates.ConclusionsVPR is a cost-saving program that would also reduce the risk of refugees arriving while infected with a vaccine preventable disease.     

Cost–benefit comparison of two proposed overseas programs for reducing chronic Hepatitis B infection among refugees: Is screening essential?

BackgroundRefugees are at an increased risk of chronic Hepatitis B virus (HBV) infection because many of their countries of origin, as well as host countries, have intermediate-to-high prevalence rates. Refugees arriving to the US are also at risk of serious sequelae from chronic HBV infection because they are not routinely screened for the virus overseas or in domestic post-arrival exams, and may live in the US for years without awareness of their infection status.MethodsA cohort of 26,548 refugees who arrived in Minnesota and Georgia during 2005–2010 was evaluated to determine the prevalence of chronic HBV infection. This prevalence information was then used in a cost–benefit analysis comparing two variations of a proposed overseas program to prevent or ameliorate the effects of HBV infection, titled ‘Screen, then vaccinate or initiate management’ (SVIM) and ‘Vaccinate only’ (VO). The analyses were performed in 2013. All values were converted to US 2012 dollars.ResultsThe estimated six year period-prevalence of chronic HBV infection was 6.8% in the overall refugee population arriving to Minnesota and Georgia and 7.1% in those ≥6 years of age. The SVIM program variation was more cost beneficial than VO. While the up-front costs of SVIM were higher than VO ($154,084 vs. $73,758; n = 58,538 refugees), the SVIM proposal displayed a positive net benefit, ranging from $24 million to $130 million after only 5 years since program initiation, depending on domestic post-arrival screening rates in the VO proposal.ConclusionsChronic HBV infection remains an important health problem in refugees resettling to the United States. An overseas screening policy for chronic HBV infection is more cost–beneficial than a ‘Vaccination only’ policy. The major benefit drivers for the screening policy are earlier medical management of chronic HBV infection and averted lost societal contributions from premature death.     

Cost of vaccinating refugees overseas versus after arrival in the United States, 2005

Since 2000, approximately 50,000 refugees have entered the United States each year from various regions of the world. Although persons with immigrant status are legally required to be vaccinated before entering the United States, this requirement does not extend to U.S.-bound persons with refugee status. After 1 year in the United States, refugees can apply for a change of status to that of legal permanent resident, at which time they are required to be fully vaccinated in accordance with recommendations of the Advisory Committee on Immunization Practices (ACIP). A potentially less costly alternative might be to vaccinate U.S.-bound refugees overseas routinely, before they depart from refugee camps. To compare the cost of vaccinating refugees overseas versus after their arrival in the United States, CDC analyzed 2005 data on the number of refugees, cost of vaccine, and cost of vaccine administration. This report summarizes the results of that analysis, which suggested that, in 2005, vaccinating 50,787 refugees overseas would have cost an estimated $7.7 million, less than one third of the estimated $26.0 million cost of vaccinating in the United States. Costs were calculated from the perspective of the U.S. health-care system. To achieve public health cost savings, routine overseas vaccination of U.S.-bound refugees should be considered.     

Costs of,and reimbursement for,vaccines: A case study at the Board of Health Refugee Services in DeKalb county,Georgia

Background

Approximately 70,000 refugees are resettled to the United States each year. Providing vaccination to arriving refugees is important to both reduce the health-related barriers to successful resettlement, and protect the health of communities where refugees resettle. It is crucial to understand the process and resources expended at the state/local and federal government levels to provide vaccinations to refugees resettling to the United States.

Objectives

We estimated costs associated with delivering vaccines to refugees at the Board of Health Refugee Services, DeKalb county, Georgia (DeKalb clinic).

Methods

Vaccination costs were estimated from two perspectives: the federal government and the DeKalb clinic. Data were collected at the DeKalb clinic regarding resources used for vaccination: staff numbers and roles; type and number of vaccine doses administered; and number of patients. Clinic costs included labor and facility-related overhead. The federal government incurred costs for vaccine purchases and reimbursements for vaccine administration.

Results

The DeKalb clinic average cost to administer the first dose of vaccine was $12.70, which is lower than Georgia Medicaid reimbursement ($14.81), but higher than the State of Georgia Refugee Health Program reimbursement ($8.00). Federal government incurred per-dose costs for vaccine products and administrative reimbursement were $42.45 (adults) and $46.74 (children).

Conclusions

The total costs to the DeKalb clinic for administering vaccines to refugees are covered, but with little surplus. Because the DeKalb clinic ‘breaks even,’ it is likely they will continue to vaccinate refugees as recommended by the Centers for Disease Control and Prevention and the Advisory Committee on Immunization Practices.     

Direct costs of a single case of refugee-imported measles in Kentucky

Background

Refugees are highly vulnerable populations with limited access to health care services. The United States accepts 50,000-75,000 refugees for resettlement annually. Despite residing in camps and other locations where vaccine-preventable disease outbreaks, such as measles, occur frequently, refugees are not required to have any vaccinations before they arrive in the United States.

Purpose

We estimated the medical and public-health response costs of a case of measles imported into Kentucky by a refugee.

Methods

The Kentucky Refugee Health Coordinator recorded the time and labor of local, state, and some federal personnel involved in caring for the refugee and implementing the public health response activities. Secondary sources were used to estimate the labor and medical care costs of the event.

Results

The total costs to conduct the response to the disease event were approximately $25,000. All costs were incurred by government, either public health department or federal, because refugee health costs are paid by the federal government and the event response costs are covered by the public health department.

Conclusion

A potentially preventable case of measles that was imported into the United States cost approximately $25,000 for the public health response.

Recommendation

To maintain the elimination of measles transmission in the United States, U.S.-bound refugees should be vaccinated overseas. A refugee vaccination program administered during the overseas health assessment has the potential to reduce the risk of importation of measles and other vaccine-preventable disease and would eliminate costs associated with public health response to imported cases and outbreaks.     

Poliovirus immunity in newly resettled adult refugees in Idaho,United States of America

BackgroundIn the United States, vaccines have eliminated wild poliovirus (WPV) infection, though resettling refugees may lack immunity and importation of WPV remains a concern.MethodsA cross-sectional survey was performed to determine the prevalence of poliovirus immunity in adult refugees resettling in Boise, Idaho, U.S.A.; immunity was evaluated using two definitions: serotypes 1, 2 and 3 positive, or serotypes 1 and 3 positive.ResultsThis survey evaluated 795 adult refugees between August 2010 and November 2012. Poliovirus immunity in adults >18 years was 55.3% for serotypes 1, 2 and 3 combined, and 60% for serotypes 1 and 3 only.ConclusionThis study demonstrated a WPV immunity rate of <60% in a recently resettled adult refugee population in the United States, reinforcing the need to ensure poliovirus immunity in all newly arrived adult refugees, either by expanding pre-departure immunization or by screening for immunity at resettlement and vaccinating when indicated.     

COVID-19 vaccination intention and behavior in a large,diverse, U.S. refugee population

IntroductionRefugees often face increased risk of exposure to COVID-19 due to their disproportionate representation in the essential workforce and crowded household conditions. There is a paucity of data about risk factors for under-immunization for COVID-19 among refugees.MethodsRefugees were surveyed in two phases that corresponded to before and after wide availability of COVID-19 vaccines. Participants were asked about their attitudes, and perceptions about COVID-19, previous acceptance of vaccines, sources utilized to obtain trusted health information, and intent to get vaccinated. The overall participant vulnerability was assessed using the social vulnerability index. In-depth semi-structured interviews were completed with key stakeholders through snowball sampling.ResultsOf 247 refugees, 244 agreed to participate in the initial survey. Among those, 140 (57.4%) intended to get vaccinated, 43 (17.6%) were unsure, and 61 (25%) did not intend to get vaccinated. In the follow up survey, all 215 who were reached, agreed to provide information about their vaccination status. Among those respondents, 141 (65.6%) were either vaccinated or expressed intent to do so, and 74 (34.4%) remained hesitant. We did not observe any significant correlation between socio-demographic variables, country of origin, and vaccination status/intent. Among those who initially intended to get vaccinated, nearly 1 in 5 changed their mind and decided to forego vaccination, and among those who initially did not plan getting vaccinated, 1 in 3 changed their mind and got vaccinated. Fears related to the vaccine, concerns that the vaccine is religiously prohibited, “wait and see” how others did with the vaccine, communication and transportation barriers were commonly cited as reason not to get vaccinated.ConclusionsOver a third of refugees in our study were hesitant to get vaccinated. Refugees desired additional education about the benefits and safety of vaccines along with easier access to vaccination clinics in their communities.     

COVID-19 vaccination refusal trends in Kenya over 2021

BackgroundVaccination refusal exacerbates global COVID-19 vaccination inequities. No studies in East Africa have examined temporal trends in vaccination refusal, precluding addressing refusal. We assessed vaccine refusal over time in Kenya, and characterized factors associated with changes in vaccination refusal.MethodsWe analyzed data from the Kenya Rapid Response Phone Survey (RRPS), a household cohort survey representative of the Kenyan population including refugees. Vaccination refusal (defined as the respondent stating they would not receive the vaccine if offered to them at no cost) was measured in February and October 2021. Proportions of vaccination refusal were plotted over time. We analyzed factors in vaccination refusal using a weighted multivariable logistic regression including interactions for time.FindingsAmong 11,569 households, vaccination refusal in Kenya decreased from 24 % in February 2021 to 9 % in October 2021. Vaccination refusal was associated with having education beyond the primary level (?4.1[?0.7,?8.9] percentage point difference (ppd)); living with somebody who had symptoms of COVID-19 in the past 14 days (?13.72[?8.9,?18.6]ppd); having symptoms of COVID-19 in the past 14 days (11.0[5.1,16.9]ppd); and distrusting the government in responding to COVID-19 (14.7[7.1,22.4]ppd). There were significant interactions with time and: refugee status and geography, living with somebody with symptoms of COVID-19, having symptoms of COVID-19, and believing in misinformation.InterpretationThe temporal reduction in vaccination refusal in Kenya likely represents substantial strides by the Kenyan vaccination program and possible learnt lessons which require examination. Going forward, there are still several groups which need specific targeting to decrease vaccination refusal and improve vaccination equity, including those with lower levels of education, those with recent COVID-19 symptoms, those who do not practice personal COVID-19 mitigation measures, refugees in urban settings, and those who do not trust the government. Policy and program should focus on decreasing vaccination refusal in these populations, and research focus on understanding barriers and motivators for vaccination.     

Estimating the economic burden of pneumococcal meningitis and pneumonia in northern Ghana in the African meningitis belt post-PCV13 introduction

BackgroundGhana introduced 13-valent pneumococcal conjugate vaccine (PCV13) into the routine infant immunization program in 2012, using a three-dose primary series without a booster. Despite ≥ 88% reported three-dose vaccination coverage since 2013, PCV13-type pneumococcal meningitis outbreaks have occurred. We estimated the ongoing economic burden of PCV13-type pneumococcal meningitis and pneumonia in northern Ghana, an area within the African meningitis belt with seasonal increases of pneumococcal meningitis post-PCV13 introduction, to inform PCV13 vaccination policy.MethodsWe performed a cross-sectional survey among patients with pneumonia or meningitis at three hospitals in northern Ghana to determine patient-level costs (direct medical and nonmedical, indirect patient and caregiver costs) incurred in household, outpatient, and inpatient settings. Pneumonia burden was estimated using 2017–2018 administrative records. Pneumococcal meningitis burden was estimated using 2017–2018 case-based surveillance data. Economic burden was reported in 2019 U.S. dollars ($) from the societal perspective.ResultsFor an area with a total population of 5,068,521, our model estimated 6,441 PCV13-type pneumonia cases and 286 PCV13-type meningitis cases occurred in a typical year post-PCV13. In the base case scenario, the total economic burden was $5,230,035 per year ($777 per case). By age group, cost per PCV13-type pneumonia case was $423 (<5 years), $911 (5–14 years), and $784 (≥15 years); cost per PCV13-type meningitis case was $2,128 (<5 years), $3,247 (5–14 years), and $2,883 (≥15 years). Most (78.0–93.4%) of the total societal cost was due to indirect costs related to deaths from PCV13-type diseases.ConclusionsThe estimated economic burden of PCV13-type disease in northern Ghana remains substantial, especially in older children and adults who were expected to have benefited from indirect effects from infant immunization. Additional interventions such as changes in the infant immunization schedule, reactive vaccination, or catch-up PCV13 vaccination may be needed to control remaining vaccine-type disease.     

Provider time and costs to vaccinate adult patients: Impact of time counseling without vaccination

Amid provider reports of financial barriers as an impediment to adult immunization, this study explores the time and costs of vaccination in adult provider practices. Both a Vaccination Time-Motion Study and Vaccine Practice Management Survey were conducted (March – October 2017) in a convenience sample of 19 family medicine (FM), internal medicine (IM), and obstetrician-gynecology (OBGYN) practices, in nine states. Practices were directly observed during a one week period; estimates were collected of time spent on activities that could not be directly observed. Cost estimates were calculated by converting staff time for performed activities. In the time-motion study, FM and IM practices spent similar time conducting vaccination activities (median?=?5?min per vaccination), while OBGYN practices spent more time (median?=?29?min per vaccination). Combining results from the time-motion study and the practice management survey, the median costs of vaccination remained similar for FM practices and IM practices at $7 and $8 per vaccination, respectively, but was substantially higher for OBGYN practices at $43 per vaccination. Factors that contributed to higher costs among OBGYN practices were the increased time to counsel patients, administer vaccines, and to plan and manage vaccine supplies. In addition, 68% of OBGYN patients who were offered and counseled to receive vaccines declined to receive them. Counseling patients who ultimately do not go on to receive a vaccine may be an important cost factor. Lower costs of vaccination services may be achieved by increasing efficiencies in workflow or the volume of vaccinations.     

Analysis of the profitability of adult vaccination in 13 private provider practices in the United States

Vaccination coverage among adults remains low in the United States. Understanding the barriers to provision of adult vaccination is an important step to increasing vaccination coverage and improving public health. To better understand financial factors that may affect practice decisions about adult vaccination, this study sought to understand how costs compared with payments for adult vaccinations in a sample of U.S. physician practices. We recruited a convenience sample of 19 practices in nine states in 2017. We conducted a time-motion study to assess the time costs of vaccination activities and conducted a survey of practice managers to assess materials, management, and dose costs and payments for vaccination. We received complete cost and payment data from 13 of the 19 practices. We calculated annual income from vaccination services by comparing estimated costs with payments received for vaccine doses and vaccine administration. Median annual total income from vaccination services was $90,343 at family medicine practices (range: $3968–$249,628), $28,267 at internal medicine practices (−$32,659–$141,034) and $2886 at obstetrics and gynecology practices (−$73,451–$23,820). Adult vaccination was profitable at the median of our sample, but there is wide variation in profitability due to differences in costs and payment rates across practices. This study provides evidence on the financial viability of adult vaccination and supports actions for improving financial viability. These results can help inform practices’ decisions whether to provide adult vaccines and contribute to keeping adults up-to-date with the recommended vaccination schedule.     

Barriers and facilitators of immunisation in refugees and migrants in Australia: an east-African case study

BackgroundImmunisation programs available in low and middle-income countries include fewer vaccines in comparison to Australia’s National Immunisation Program. As a result, refugees and migrants may have a heightened risk of being inadequately immunised upon arrival to Australia. Several studies have suggested that East African immigrants have low vaccination coverage. As such, the aim of this study was to explore the underlying attitudes, barriers and facilitators to immunisation in east African communities in two states of Australia: New South Wales and Victoria.MethodsA qualitative study involving 17 semi-structured, in-depth interviews were undertaken with East African refugees and migrants living in two states of Australia: New South Wales and Victoria. These refugees and migrants were from four key East African countries: Kenya, Somalia, Ethiopia and South Sudan. Thematic analysis was undertaken to analyse and interpret the results.ResultsLanguage barriers, low risk perception and a lack of education were the key barriers identified by participants. Facilitators mentioned included the development of resources in participants’ languages and the implementation of reminder systems consistently across all GP practices. There was also a unanimous agreement amongst participants that community organisations need to play a greater role in the dissemination of information about immunisation.ConclusionsFurther research needs to be undertaken with regards to how education about immunisation is delivered and disseminated to refugee and migrant communities. Current findings also support the need to improve the health literacy of refugees and migrants by providing culturally and linguistically appropriate resources in participants’ respective languages.     

Sero-epidemiology of Hepatitis B Among New Refugees to Minnesota

Hepatitis B virus (HBV) infection is endemic in many parts of the world, and prevailing conditions in refugee situations result in greater risk of infection. The objectives of this study were to determine the period prevalence of HBV infection among primary refugees in Minnesota during 1998-2001; describe trends in prevalence over time and identify patterns of infection and immunity in various refugee populations. A retrospective analysis of health examination data from the Minnesota Department of Health was conducted to examine serologic markers for hepatitis B: HBcAb, HbsAg, and HBsAb among 12,505 refugees who participated in the voluntary domestic health examination from 1998 to 2001. One hundred and eleven refugees had at least one immunization before arrival and were excluded. There was documented HBV test results in 8,754 (70.6%) of refugees; period prevalence of hepatitis B infection was 7.1%. Africans were three times more likely and Asians 2.4 times more likely to be infected than Europeans (P < 0.001). Older African refugees and African males were more likely to be infected than younger African refugees and women African refugees (P < 0.001). Younger persons below 30 years of age accounted for over 70% of all infected refugees in this study. Reducing the burden of infection among refugees requires enhanced provider awareness as well as intensified efforts aimed at identifying new at-risk populations, modifying risk factors, and implementing preventive and treatment strategies at various levels in the refugee resettlement process.     

Enhanced Transitions of Care for Medically Complex Refugees

Background

Between 2015 and 2019, 261,091 refugees were resettled through the U.S. Refugee Admissions Program. Few are chronically ill, but previously these went to emergency rooms upon arrival. We designed a pilot program to anticipate, assess, and safely assume care of chronic health needs and stabilize sick and medically complex refugees upon arrival.

Clinical Operations

Academic internal medicine and pediatrics clinics are linked to the Washington State Refugee Health Program and Refugee Resettlement Agencies. Arriving refugees deemed medically complex through overseas medical evaluation or post-arrival were selected for the program.

Metrics

We reviewed biodata of 2,947 refugees deemed medically complex. We referred five hundred and sixty one (19%) of these for evaluation, and 257 (46%) of referrals received care.

Discussion

Safe transitions of care are standard practice in medical systems. This innovation in Seattle is one example of a system for the safe and cost-effective relocation of refugees with complex illnesses.

     

Economic burden of seasonal influenza in the United States

BackgroundSeasonal influenza is responsible for a large disease and economic burden. Despite the expanding recommendation of influenza vaccination, influenza has continued to be a major public health concern in the United States (U.S.). To evaluate influenza prevention strategies it is important that policy makers have current estimates of the economic burden of influenza.ObjectiveTo provide an updated estimate of the average annual economic burden of seasonal influenza in the U.S. population in the presence of vaccination efforts.MethodsWe evaluated estimates of age-specific influenza-attributable outcomes (ill-non medically attended, office-based outpatient visit, emergency department visits, hospitalizations and death) and associated productivity loss. Health outcome rates were applied to the 2015 U.S. population and multiplied by the relevant estimated unit costs for each outcome. We evaluated both direct healthcare costs and indirect costs (absenteeism from paid employment) reporting results from both a healthcare system and societal perspective. Results were presented in five age groups (<5 years, 5–17 years, 18–49 years, 50–64 years and ≥65 years of age).ResultsThe estimated average annual total economic burden of influenza to the healthcare system and society was $11.2 billion ($6.3–$25.3 billion). Direct medical costs were estimated to be $3.2 billion ($1.5–$11.7 billion) and indirect costs $8.0 billion ($4.8–$13.6 billion). These total costs were based on the estimated average numbers of (1) ill-non medically attended patients (21.6 million), (2) office-based outpatient visits (3.7 million), (3) emergency department visit (0.65 million) (4) hospitalizations (247.0 thousand), (5) deaths (36.3 thousand) and (6) days of productivity lost (20.1 million).ConclusionsThis study provides an updated estimate of the total economic burden of influenza in the U.S. Although we found a lower total cost than previously estimated, our results confirm that influenza is responsible for a substantial economic burden in the U.S.     

Routine immunization services costs and financing in China, 2015

ObjectiveTo estimate the costs of routine immunization (RI) services in China in 2015, to provide objective data relevant to investment in the Expanded Program on Immunization, and to contribute to global data on costing and financing of RI.MethodsThe study was conducted between January and March 2016. We selected 276 villages, 138 townships, 46 counties, and 40 prefectures from 15 provinces as investigation sites at random, stratified by eastern, middle, and western regions. Direct cost items included vaccines, personnel, cold chain, surveillance, communication, training, and supervision at the national, provincial, prefecture, county, township, and village levels. We obtained financial data from governmental and external sources. Indirect costs of RI included parents’ transportation costs and productivity lost due to taking their children for vaccination.ResultsTotal direct costs were $92.42 for each child fully immunized ($4.20/dose), which equates to $1529.55 million per birth cohort. RI costs were higher in the eastern region than in the western region, and higher than that of the central region. Vaccination coverage was positively associated with direct routine immunization costs. The cost of the recommended vaccines was $19.08/child and vaccine only accounted for 20.64% of total costs. Operational cost, including surveillance, communication, training and supervision, was $217.31/child, accounting for 14.21% of total cost. The indirect cost per child was $72.86; the total indirect cost was $1205.83 million for the birth cohort. Government investment in RI accounted for about 70% of total costs. Revenue from sales of private-sector vaccine supported the remaining 30% of RI costs.ConclusionsWhile government financing has increased, some operating costs continue to be provided from revenue generated by sales of Category 2 (private-sector) vaccines to families. China could benefit from bringing new and underutilized vaccines into the EPI system based on evidence that includes routine immunization vaccine and operations costs.     

Vaccine coverage and adherence to EPI schedules in eight resource poor settings in the MAL-ED cohort study

BackgroundLaunched in 1974, the Expanded Program on Immunization (EPI) is estimated to prevent two-three million deaths annually from polio, diphtheria, tuberculosis, pertussis, measles, and tetanus. Additional lives could be saved through better understanding what influences adherence to the EPI schedule in specific settings.MethodsThe Etiology, Risk Factors and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health and Development (MAL-ED) study followed cohorts in eight sites in South Asia, Africa, and South America and monitored vaccine receipt over the first two years of life for the children enrolled in the study. Vaccination histories were obtained monthly from vaccination cards, local clinic records and/or caregiver reports. Vaccination histories were compared against the prescribed EPI schedules for each country, and coverage rates were examined in relation to the timing of vaccination. The influence of socioeconomic factors on vaccine timing and coverage was also considered.ResultsCoverage rates for EPI vaccines varied between sites and by type of vaccine; overall, coverage was highest in the Nepal and Bangladesh sites and lowest in the Tanzania and Brazil sites. Bacillus Calmette-Guérin coverage was high across all sites, 87–100%, whereas measles vaccination rates ranged widely, 73–100%. Significant delays between the scheduled administration age and actual vaccination date were present in all sites, especially for measles vaccine where less than 40% were administered on schedule. A range of socioeconomic factors were significantly associated with vaccination status in study children but these results were largely site-specific.ConclusionsOur findings highlight the need to improve measles vaccination rates and reduce delayed vaccination to achieve EPI targets related to the establishment of herd immunity and reduction in disease transmission.     

Comparison of mRNA vaccine effectiveness against COVID-19-associated hospitalization by vaccination source: Immunization information systems,electronic medical records,and self-report—IVY Network,February 1–August 31, 2022

BackgroundAccurate determination of COVID-19 vaccination status is necessary to produce reliable COVID-19 vaccine effectiveness (VE) estimates. Data comparing differences in COVID-19 VE by vaccination sources (i.e., immunization information systems [IIS], electronic medical records [EMR], and self-report) are limited. We compared the number of mRNA COVID-19 vaccine doses identified by each of these sources to assess agreement as well as differences in VE estimates using vaccination data from each individual source and vaccination data adjudicated from all sources combined.MethodsAdults aged ≥18 years who were hospitalized with COVID-like illness at 21 hospitals in 18 U.S. states participating in the IVY Network during February 1–August 31, 2022, were enrolled. Numbers of COVID-19 vaccine doses identified by IIS, EMR, and self-report were compared in kappa agreement analyses. Effectiveness of mRNA COVID-19 vaccines against COVID-19-associated hospitalization was estimated using multivariable logistic regression models to compare the odds of COVID-19 vaccination between SARS-CoV-2-positive case-patients and SARS-CoV-2-negative control-patients. VE was estimated using each source of vaccination data separately and all sources combined.ResultsA total of 4499 patients were included. Patients with ≥1 mRNA COVID-19 vaccine dose were identified most frequently by self-report (n = 3570, 79 %), followed by IIS (n = 3272, 73 %) and EMR (n = 3057, 68 %). Agreement was highest between IIS and self-report for 4 doses with a kappa of 0.77 (95 % CI = 0.73–0.81). VE point estimates of 3 doses against COVID-19 hospitalization were substantially lower when using vaccination data from EMR only (VE = 31 %, 95 % CI = 16 %–43 %) than when using all sources combined (VE = 53 %, 95 % CI = 41 %–62%).ConclusionVaccination data from EMR only may substantially underestimate COVID-19 VE.