Lessons Learned from COVID-19 Response in Correctional and Detention Facilities.

The COVID-19 pandemic disproportionately affected persons held in and working in correctional and detention facilities, causing facilities' traditional priorities to shift when healthcare and public health needs temporarily drove many aspects of operations. During July-August 2022, we interviewed members of health departments and criminal justice organizations to document lessons learned from the COVID-19 response in correctional settings. Participants valued enhanced partnerships, flexibility, and innovation, as well as real-time data and corrections-specific public health guidance. Challenges included cross-sector collaborations, population density, scarcity of equipment and supplies, and mental health. Most participants reported improved relationships between criminal justice and public health organizations during the pandemic. Lessons from COVID-19 can be applied to everyday public health preparedness and emergency response in correctional facilities by ensuring representation of correctional health in public health strategy and practice and providing timely, data-driven, and partner-informed guidance tailored to correctional environments when public health needs arise.

Involuntary displacement and self-reported health in a cross-sectional survey of people experiencing homelessness in Denver, Colorado, 2018-2019.

BACKGROUND: The number of people experiencing unsheltered homelessness in the U.S. is increasing. Municipalities have responded with punitive responses such as involuntary displacement (i.e., encampment sweeps, move along orders), but little is known about the impact of involuntary displacement on health. The purpose of this study was to investigate the association between broadly defined experiences of involuntary displacement and self-reported health conditions among people experiencing homelessness. METHODS: We used logistic regression models to generate odds ratios using publicly available data from a cross-sectional sample of people experiencing homelessness in Denver, Colorado, during September 2018-February 2019. Hosmer-Lemeshow Goodness of Fit tests were used to assess model fit. RESULTS: Among 397 people experiencing homelessness, involuntary displacement was significantly associated with self-reported infectious diseases (adjusted odds ratio (aOR) 2.09, 95% CI 1.27, 3.41), substance and alcohol use (aOR 2.83; 95% CI 1.70, 4.73), climate-related conditions (aOR 2.27; 95% CI 1.35, 3.83), and worsening mental health (aOR 2.00; 95% CI 1.24, 3.24) after controlling for potential confounders. No statistically significant associations were identified between involuntary displacement and injuries, musculoskeletal issues, chronic conditions, and chronic mental and emotional issues. CONCLUSIONS: This research quantifies the association between involuntary displacement and multiple infectious and non-infectious health outcomes. While city officials attempt to grapple with increasing unsheltered homelessness, it is important to understand what harms are occurring that are associated with current policies. Our research adds to the growing body of literature that involuntary displacement is a harmful response to unsheltered homelessness. Alternative approaches focused on connections to housing and social services should be prioritized.

A qualitative assessment of cleaning and hand hygiene practices at shelters serving people experiencing homelessness during the COVID-19 pandemic, Atlanta, GA - May-June, 2020.

BACKGROUND: Cleaning practices and hand hygiene are important behaviors to prevent and control the spread of infectious disease, especially in congregate settings. This project explored hygiene- and cleaning-related experiences in shelters serving people experiencing homelessness (PEH) during May-June 2020 of the COVID-19 pandemic. METHODS: We conducted qualitative, in-depth interviews by phone with 22 staff from six shelters in Atlanta, Georgia. The interview guide included questions about cleaning routines, cleaning barriers and facilitators, cleaning promotion, hand hygiene promotion, and hand hygiene barriers and facilitators. We analyzed interview transcripts using thematic analysis. RESULTS: Multiple individuals, such as shelter individuals (clients), volunteers, and staff, played a role in shelter cleaning. Staff reported engaging in frequent hand hygiene and cleaning practices. Barriers to cleaning included staffing shortages and access to cleaning supplies. Staff reported barriers (e.g., differing perceptions of cleanliness) for clients who were often involved in cleaning activities. Barriers to hand hygiene included limited time to wash hands, forgetting, and inconvenient handwashing facilities. Specific guidance about when and how to clean, and what supplies to use, were requested. CONCLUSION: During the early months of the COVID-19 pandemic, shelters serving PEH in the Atlanta-metro area needed resources and support to ensure sufficient staffing and supplies for cleaning activities. As part of future pandemic planning and outbreak prevention efforts, shelters serving PEH could benefit from specific guidance and training materials on cleaning and hand hygiene practices.

Possible Undetected Mpox Infection Among Persons Accessing Homeless Services and Staying in Encampments - San Francisco, California, October-November 2022.

Monkeypox (mpox) is a disease caused by an Orthopoxvirus. The 2022 multinational outbreak, which began in May 2022, has spread primarily by close skin-to-skin contact, including through sexual contact. Persons experiencing homelessness have been disproportionately affected by severe mpox (1). However, mpox prevalence and transmission pathways among persons experiencing homelessness are not known, and persons experiencing homelessness have not been specifically recommended to receive mpox vaccine during the 2022 outbreak (2,3). During October 25-November 3, 2022, a CDC field team conducted an orthopoxvirus seroprevalence survey among persons accessing homeless services or staying in encampments, shelters, or permanent supportive housing in San Francisco, California that had noted at least one case of mpox or served populations at risk. During field team visits to 16 unique sites, 209 participants completed a 15-minute survey and provided a blood specimen. Among 80 participants aged <50 years who did not report smallpox or mpox vaccination or previous mpox infection, two (2.5%) had detectable antiorthopoxvirus immunoglobulin (Ig) G antibody. Among 73 participants who did not report mpox vaccination or previous mpox infection and who were tested for IgM, one (1.4%) had detectable antiorthopoxvirus IgM. Together, these results suggest that three possible undetected mpox infections occurred among a sample of persons experiencing homelessness, highlighting the need to ensure that community outreach and prevention interventions, such as vaccination, are accessible to this population.

Incidence of SARS-CoV-2 infection and associated risk factors among staff and residents at homeless shelters in King County, Washington: an active surveillance study.

Homeless shelter residents and staff may be at higher risk of SARS-CoV-2 infection. However, SARS-CoV-2 infection estimates in this population have been reliant on cross-sectional or outbreak investigation data. We conducted routine surveillance and outbreak testing in 23 homeless shelters in King County, Washington, to estimate the occurrence of laboratory-confirmed SARS-CoV-2 infection and risk factors during 1 January 2020-31 May 2021. Symptom surveys and nasal swabs were collected for SARS-CoV-2 testing by RT-PCR for residents aged ≥3 months and staff. We collected 12,915 specimens from 2,930 unique participants. We identified 4.74 (95% CI 4.00-5.58) SARS-CoV-2 infections per 100 individuals (residents: 4.96, 95% CI 4.12-5.91; staff: 3.86, 95% CI 2.43-5.79). Most infections were asymptomatic at the time of detection (74%) and detected during routine surveillance (73%). Outbreak testing yielded higher test positivity than routine surveillance (2.7% versus 0.9%). Among those infected, residents were less likely to report symptoms than staff. Participants who were vaccinated against seasonal influenza and were current smokers had lower odds of having an infection detected. Active surveillance that includes SARS-CoV-2 testing of all persons is essential in ascertaining the true burden of SARS-CoV-2 infections among residents and staff of congregate settings.

Population-Level Health Effects of Involuntary Displacement of People Experiencing Unsheltered Homelessness Who Inject Drugs in US Cities.

Importance: At least 500 000 people in the US experience homelessness nightly. More than 30% of people experiencing homelessness also have a substance use disorder. Involuntary displacement is a common practice in responding to unsheltered people experiencing homelessness. Understanding the health implications of displacement (eg, "sweeps," "clearings," "cleanups") is important, especially as they relate to key substance use disorder outcomes. Objective: To estimate the long-term health effects of involuntary displacement of people experiencing homelessness who inject drugs in 23 US cities. Design, Setting, and Participants: A closed cohort microsimulation model that simulates the natural history of injection drug use and health outcomes among people experiencing homelessness who inject drugs in 23 US cities. The model was populated with city-level data from the Centers for Disease Control and Prevention's National HIV Behavioral Surveillance system and published data to make representative cohorts of people experiencing homelessness who inject drugs in those cities. Main Outcomes and Measures: Projected outcomes included overdose mortality, serious injection-related infections and mortality related to serious injection-related infections, hospitalizations, initiations of medications for opioid use disorder, and life-years lived over a 10-year period for 2 scenarios: "no displacement" and "continual involuntary displacement." The population-attributable fraction of continual displacement to mortality was estimated among this population. Results: Models estimated between 974 and 2175 additional overdose deaths per 10 000 people experiencing homelessness at 10 years in scenarios in which people experiencing homelessness who inject drugs were continually involuntarily displaced compared with no displacement. Between 611 and 1360 additional people experiencing homelessness who inject drugs per 10 000 people were estimated to be hospitalized with continual involuntary displacement, and there will be an estimated 3140 to 8812 fewer initiations of medications for opioid use disorder per 10 000 people. Continual involuntary displacement may contribute to between 15.6% and 24.4% of additional deaths among unsheltered people experiencing homelessness who inject drugs over a 10-year period. Conclusion and Relevance: Involuntary displacement of people experiencing homelessness may substantially increase drug-related morbidity and mortality. These findings have implications for the practice of involuntary displacement, as well as policies such as access to housing and supportive services, that could mitigate these harms.

SARS-CoV-2 outbreak among staff and evacuees at Operation Allies Welcome Safe Havens.

We report on five SARS-CoV-2 congregate setting outbreaks at U.S. Operation Allies Welcome Safe Havens/military facilities. Outbreak data were collected, and attack rates were calculated for various populations. Even in vaccinated populations, there was rapid spread, illustrating the importance of institutional prevention and mitigation policies in congregate settings.

Strengthening Public Health Capacity to Address Infectious Diseases: Lessons From 3 Centers of Excellence in Public Health and Homelessness.

People experiencing homelessness are disproportionately affected by infectious diseases and often face barriers to receiving appropriate medical treatment. Responding to the needs of people experiencing homelessness requires state and local health departments to integrate information sources and coordinate multisector efforts. From 2021 to 2023, the CDC Foundation, in cooperation with the Centers for Disease Control and Prevention, established pilot Centers of Excellence in Public Health and Homelessness in Seattle, Washington; San Francisco, California; and the state of Minnesota. These centers strengthened their capacity to address the needs of people experiencing homelessness by supporting cross-sector partnerships, assessing the interoperability of data systems, prioritizing infectious disease needs, and identifying health disparities. These programs demonstrated that health departments are heterogeneous entities with differing resources and priorities. They also showed the importance of employing dedicated public health staff focused on homelessness, establishing diverse partnerships and the need for support from local leaders to address homelessness.

Communicating Effectively With People Experiencing Homelessness to Prevent Infectious Diseases.

BACKGROUND: People experiencing homelessness (PEH) are disproportionately affected by many infectious diseases, including coronavirus disease 2019 (COVID-19). However, communication efforts during public health emergencies like the COVID-19 pandemic often do not consider the unique needs of PEH. We examined how PEH seek and receive health information and how traditional health communication methods resonate with them. METHODS: We conducted in-person focus groups with PEH in 4 jurisdictions (Cincinnati, Ohio; Denver, Colorado; Sacramento, California; and the Bronx, New York) during July 2021. RESULTS: Findings from 15 focus groups with PEH (n = 53) revealed the need for trusted messengers and consistent messaging across local organizations, as PEH seek to verify information they receive from multiple sources. PEH overwhelmingly preferred to receive health information through face-to-face conversations, especially with healthcare providers with whom they had an established relationship, but they also cited news media, the internet, and social media as their main sources for obtaining health information. PEH reported that effective communication products pair a recommended action with instructions and resources about how to take that action within their community. CONCLUSIONS: These findings support healthcare providers collaborating with public health agencies to ensure that infectious disease prevention messages for PEH are provided by trusted messengers, multimodal, paired with resources, and consistent.

The Clinical and Genomic Epidemiology of Rhinovirus in Homeless Shelters-King County, Washington.

BACKGROUND: Rhinovirus (RV) is a common cause of respiratory illness in all people, including those experiencing homelessness. RV epidemiology in homeless shelters is unknown. METHODS: We analyzed data from a cross-sectional homeless shelter study in King County, Washington, October 2019-May 2021. Shelter residents or guardians aged ≥3 months reporting acute respiratory illness completed questionnaires and submitted nasal swabs. After 1 April 2020, enrollment expanded to residents and staff regardless of symptoms. Samples were tested by multiplex RT-PCR for respiratory viruses. A subset of RV-positive samples was sequenced. RESULTS: There were 1066 RV-positive samples with RV present every month of the study period. RV was the most common virus before and during the coronavirus disease 2019 (COVID-19) pandemic (43% and 77% of virus-positive samples, respectively). Participants from family shelters had the highest prevalence of RV. Among 131 sequenced samples, 33 RV serotypes were identified with each serotype detected for ≤4 months. CONCLUSIONS: RV infections persisted through community mitigation measures and were most prevalent in shelters housing families. Sequencing showed a diversity of circulating RV serotypes, each detected over short periods of time. Community-based surveillance in congregate settings is important to characterize respiratory viral infections during and after the COVID-19 pandemic. CLINICAL TRIALS REGISTRATION: NCT04141917.

Human Parainfluenza Virus in Homeless Shelters before and during the COVID-19 Pandemic, Washington, USA.

To determine the epidemiology of human parainfluenza virus in homeless shelters during the COVID-19 pandemic, we analyzed data and sequences from respiratory specimens collected in 23 shelters in Washington, USA, during 2019-2021. Two clusters in children were genetically similar by shelter of origin. Shelter-specific interventions are needed to reduce these infections.

Monkeypox Case Investigation - Cook County Jail, Chicago, Illinois, July-August 2022.

Knowledge about monkeypox transmission risk in congregate settings is limited. In July 2022, the Chicago Department of Public Health (CDPH) confirmed a case of monkeypox in a person detained in Cook County Jail (CCJ) in Chicago, Illinois. This case was the first identified in a correctional setting in the United States and reported to CDC during the 2022 multinational monkeypox outbreak. CDPH collaborated with CCJ, the Illinois Department of Public Health (IDPH), and CDC to evaluate transmission risk within the facility. Fifty-seven residents were classified as having intermediate-risk exposures to the patient with monkeypox during the 7-day interval between the patient's symptom onset and his isolation. (Intermediate-risk exposure was defined as potentially being within 6 ft of the patient with monkeypox for a total of ≥3 hours cumulatively, without wearing a surgical mask or respirator, or potentially having contact between their own intact skin or clothing and the skin lesions or body fluids from the patient or with materials that were in contact with the patient's skin lesions or body fluids.) No secondary cases were identified among a subset of 62% of these potentially exposed residents who received symptom monitoring, serologic testing, or both. Thirteen residents accepted postexposure prophylaxis (PEP), with higher acceptance among those who were offered counseling individually or in small groups than among those who were offered PEP together in a large group. Monkeypox virus (MPXV) DNA, but no viable virus, was detected on one surface in a dormitory where the patient had been housed with other residents before he was isolated. Although monkeypox transmission might be limited in similar congregate settings in the absence of higher-risk exposures, congregate facilities should maintain recommended infection control practices in response to monkeypox cases, including placing the person with monkeypox in medical isolation and promptly and thoroughly cleaning and disinfecting spaces where the person has spent time. In addition, officials should provide information to residents and staff members about monkeypox symptoms and transmission modes, facilitate confidential monkeypox risk and symptom disclosure and prompt medical evaluation for symptoms that are reported, and provide PEP counseling in a private setting.

COVID-19 Vaccine Acceptability Among Clients and Staff of Homeless Shelters in Detroit, Michigan, February 2021.

Understanding COVID-19 vaccine acceptability among clients and staff of homeless shelters can inform public health efforts focused on communicating with and educating this population about COVID-19 vaccines and thus improve vaccine uptake. The objective of this study was to assess COVID-19 vaccine acceptability and uptake among people in homeless shelters in Detroit, Michigan. A cross-sectional study was conducted from February 9 to 23, 2021. Seventeen homeless shelters were surveyed: seven male-only, three male/female, and seven women and family shelters. All clients and staff aged ≥18 years and able to complete a verbal survey in English or with a translator were eligible to participate; of the 168 individuals approached, 26 declined, leaving a total sample of 106 clients and 36 staff participating in the study. The median client and staff ages were 44 and 54 years, respectively. Most participants (>80%) identified as non-Hispanic Black or African American. Sixty-one (57.5%) clients and 27 (75.5%) staff had already received or planned to receive a COVID-19 vaccination. Twelve (11.3%) clients and four (11.1%) staff were unsure, and 33 (31.1%) clients and five (13.9%) staff did not plan to get vaccinated. Reasons for hesitancy were concerns over side effects (29 clients [64.4%] and seven staff [77.8%]) and unknown long-term health impacts (26 clients [57.8%] and six staff [66.7%]). More than half of the clients had already received or planned to receive the vaccine. Continuing efforts such as vaccine education for hesitant clients and staff and having accessible vaccine events for this population may improve acceptability and uptake.

COVID-19 Vaccine Acceptability Among People Experiencing Homelessness in Central Florida and Southern Nevada, March-June 2021.

CONTEXT: Understanding COVID-19 vaccine acceptability among people experiencing homelessness is critical to improve vaccine coverage during the COVID-19 pandemic. Little is known about COVID-19 vaccine acceptability people experiencing unsheltered homelessness (PEUH). OBJECTIVE: To identify and describe motivators for receiving a COVID-19 vaccine and reasons for hesitancy, information sources utilized and trusted for vaccine decision making, logistical barriers to receiving vaccination, and what might increase comfortability to receive a COVID-19 vaccination among PEUH. DESIGN: Cross-sectional survey design, implemented from March to June 2021. SETTING: Two US cities: Las Vegas and Nevada (urban), and Orlando, Florida (suburban). PARTICIPANTS: People experiencing predominantly unsheltered homelessness accessing handwashing stations and other wrap-around social services at program sites managed by Clean the World Foundation. MAIN OUTCOME MEASURES: The main outcome measures assessed included survey responses about current vaccine receipt (if participants have already received one or more doses of a COVID-19 vaccine), intention to receive a COVID-19 vaccine if not already received, motivators for receiving or wanting to receive a vaccine, reasons for hesitancy or uncertainty about receiving a vaccine, sources of information regarding COVID-19 vaccines, and actual or anticipated logistical barriers or challenges to receiving COVID-19 vaccines. RESULTS: Among 864 participants, 465 (53.8%) were classified as "vaccine accepting," and 399 were classified "vaccine hesitant or undecided." The primary motivator to be vaccinated was to protect their health (212, 45.6%). Hesitant or undecided participants reported that vaccines were too new (269, 67.4%) or they needed more information (223, 55.9%) and were more likely to receive information from social media than accepting participants (80.0% vs 58.3%, P < .001). Logistical barriers to vaccination included distance to vaccination locations (85, 21.3%), lack of transportation (79, 19.8%), and limited time (64, 16%). CONCLUSIONS: Vaccination efforts to reach PEUH should consider how information and logistical needs may be addressed.

Morbidity and Mortality Among Adults Experiencing Homelessness Hospitalized With COVID-19.

People experiencing homelessness (PEH) are at higher risk for chronic health conditions, but clinical characteristics and outcomes for PEH hospitalized with coronavirus disease 2019 (COVID-19) are not known. We analyzed population-based surveillance data of COVID-19-associated hospitalizations during 1 March to 31 May 2020. Two percent of the people hospitalized with COVID-19 for whom a housing status was recorded were homeless. Of 199 cases in the analytic sample, most were of racial/ethnic minority groups and had underlying health conditions. Clinical outcomes such as ICU admission, respiratory support including mechanical ventilation, and deaths were documented. Hispanic and non-Hispanic black persons accounted for most mechanical ventilation and deaths. Severe illness was common among persons experiencing homelessness who were hospitalized with COVID-19.

Upsurge of Conjugate Vaccine Serotype 4 Invasive Pneumococcal Disease Clusters Among Adults Experiencing Homelessness in California, Colorado, and New Mexico.

After 7-valent pneumococcal conjugate vaccine introduction in the United States in 2000, invasive pneumococcal disease (IPD) due to serotype 4 greatly decreased in children and adults. Starting in 2013, serotype 4 IPD incidence increased among adults within 3 of 10 Active Bacterial Core surveillance sites. Of 325 serotype 4 cases among adults in 2010-2018, 36% were persons experiencing homelessness (PEH); incidence of serotype 4 IPD among PEH was 100-300 times higher than in the general population within these 3 areas. Genome sequencing for isolates recovered 2015-2018 (n = 246), revealed that increases in serotype 4 IPD were driven by lineages ST10172, ST244, and ST695. Within each lineage, clusters of near-identical isolates indicated close temporal relatedness. Increases in serotype 4 IPD were limited to Colorado, California, and New Mexico, with highest increases among PEH, who were at increased risk for exposure to and infections caused by these strains.

Haemophilus influenzae Serotype a (Hia) Carriage in a Small Alaska Community After a Cluster of Invasive Hia Disease, 2018.

BACKGROUND: Between May and July 2018, 4 Haemophilus influenzae serotype a (Hia) infections occurred in a remote Alaska community. We performed a public health response to prevent further illness and understand Hia carriage. METHODS: We collected oropharyngeal samples community-wide to evaluate baseline carriage. Risk factors were evaluated by interview. We offered prophylactic rifampin to individuals in contact with invasive Hia patients (contacts) and to all children aged <10 years. Oropharyngeal samples were collected again 8 weeks after rifampin distribution. Samples were tested using real-time polymerase chain reaction and culture. RESULTS: At baseline, 4 of 27 (14.8%) contacts and 7 of 364 (1.9%) noncontacts (P < .01) carried Hia. Contacts aged <10 years were more likely to carry Hia at any timepoint (11/18 [61%]) compared to contacts aged ≥10 years (3/34 [8.8%]), noncontacts aged <10 years (2/139 [1.4%]), and noncontacts ≥10 years (6/276 [2.2%]) (P < .001 for all). Hia carriers were clustered in 9 households (7% of total households). At the household level, carriage was associated with households with ≥1 contact (prevalence ratio [PR], 5.6 [95% confidence interval {CI}, 1.3-21.6]), crowding (PR, 7.7 [95% CI, 1.1-199.5]), and ≥3 tobacco users (PR, 5.0 [95% CI, 1.2-19.6]). Elevated carriage prevalence persisted in contacts compared to noncontacts 8 weeks after rifampin distribution (6/25 [24%] contacts, 2/114 [1.8%] noncontacts; P < .001). CONCLUSIONS: Hia carriage prevalence was significantly higher among contacts than noncontacts. Rifampin prophylaxis did not result in a reduction of Hia carriage prevalence in this community.

Coronavirus Disease 2019 (COVID-19) Prevalences Among People Experiencing Homelessness and Homelessness Service Staff During Early Community Transmission in Atlanta, Georgia, April-May 2020.

BACKGROUND: In response to reported coronavirus disease 2019 (COVID-19) outbreaks among people experiencing homelessness (PEH) in other US cities, we conducted multiple, proactive, facility-wide testing events for PEH living sheltered and unsheltered and homelessness service staff in Atlanta, Georgia. We describe the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) prevalence and associated symptoms, and review shelter infection prevention and control (IPC) policies. METHODS: PEH and staff were tested for SARS-CoV-2 by reverse transcription polymerase chain reaction (RT-PCR) during 7 April-6 May 2020. A subset of PEH and staff was screened for symptoms. Shelter assessments were conducted concurrently at a convenience sample of shelters using a standardized questionnaire. RESULTS: Overall, 2875 individuals at 24 shelters and 9 unsheltered outreach events underwent SARS-CoV-2 testing, and 2860 (99.5%) had conclusive test results. The SARS-CoV-2 prevalences were 2.1% (36/1684) among PEH living sheltered, 0.5% (3/628) among PEH living unsheltered, and 1.3% (7/548) among staff. Reporting fever, cough, or shortness of breath in the last week during symptom screening was 14% sensitive and 89% specific for identifying COVID-19 cases, compared with RT-PCR. Prevalences by shelter ranged 0-27.6%. Repeat testing 3-4 weeks later at 4 shelters documented decreased SARS-CoV-2 prevalences (0-3.9%). Of 24 shelters, 9 completed shelter assessments and implemented IPC measures as part of the COVID-19 response. CONCLUSIONS: PEH living in shelters experienced a higher SARS-CoV-2 prevalence compared with PEH living unsheltered. Facility-wide testing in congregate settings allowed for the identification and isolation of COVID-19 cases, and is an important strategy to interrupt SARS-CoV-2 transmission.

Data Sources That Enumerate People Experiencing Homelessness in the United States: Opportunities and Challenges for Epidemiologic Research.

Homelessness is associated with a multitude of poor health outcomes. However, the full extent of the risks associated with homelessness is not possible to quantify without reliable population data. Here, we outline 3 federal, publicly available data sources for estimating the number of people experiencing homelessness in the United States. We describe the appropriate uses and limitations of each data source in the context of infectious disease epidemiology. These data sources provide an opportunity to expand current research and develop actionable analyses.

Hepatitis A vaccine immunogenicity 25 years after vaccination in Alaska.

The hepatitis A vaccine is recommended for all children greater than or equal to 1 year of age, however, the duration of vaccine protection is unknown and protection through adulthood is crucial to prevent symptomatic hepatitis later in life. We report on 25 years of follow-up of a cohort of Alaska Native individuals who were vaccinated in early childhood. We assessed the duration of vaccine protection by calculating the geometric mean concentration and proportion of participants with protective levels of IgG antibody to hepatitis A virus (anti-HAV) (≥20 mIU/mL) every 2 to 3 years. We estimated the amount of time until the anti-HAV dropped below protective levels using survival analyses. At 25 years, 43 of the original 144 participants were available, mean anti-HAV levels were 91.5 mIU/mL, and 35 (81.4%) had protective levels of anti-HAV. Using data from all persons and all time points, a survival analysis estimated 78.7% of participants had protective levels of anti-HAV at 25 years. The high level of protective antibodies in this cohort indicate that supplemental doses of hepatitis A vaccine are not needed 25 years after completion of the vaccine series.