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USU cohort study investigates COVID-19 impacts on DOD personnel

Image of Military health personnel wearing a mask and a face shield holding up a sign that has the number eighteen on it . Navy Hospital Corpsman 3rd Class Charles Cambern holds up a numbered sign as patients circle through to receive the COVID-19 vaccine at Walter Reed National Military Medical Center, in Bethesda, Maryland. WRNMMC is one of 10 DOD sites undertaking the EPICC study to better understand COVID-19 disease. (U.S. Navy photo by Ricardo Reyes)

2/18/2021 By: HealthdotMil Staff

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The Uniformed Services University of the Health Sciences’ Infectious Disease Clinical Research Program is leading a multi-year study to identify risk factors for COVID-19 in the military population, understand the symptoms and disease course, and investigate clinical outcomes.

Epidemiology, Immunology, and Clinical Characteristics of Emerging Infectious Diseases with Pandemic Potential – or EPICC – study hopes to inform the Military Health System on ways to improve the patient care and treatment, infection, and disease prevention of those with COVID-19. USU is working in partnership with a network of military commands, treatment facilities, and laboratories across the country for EPICC.

Findings from the study “will support further understanding of the impact of SARS-COV-2 infection on active-duty readiness, acute and chronic clinical outcomes, the effectiveness of new treatments and vaccines, and address questions related to the emergence of new variants and their clinical impact,” said Dr. Brian Agan, deputy science director of IDCRP and principal investigator of the study.

The study is also evaluating how long the immune response to the COVID-19 vaccines lasts, breakthrough infections – which happen when a vaccinated individual becomes sick from the same illness the vaccination is designed to prevent – and how they behave over time, and estimating vaccine effectiveness, said Agan, who is also an employee of the Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc.

Department of Defense service members and MHS beneficiaries of any age with COVID-19-like illness who are admitted to the hospital or treated as outpatients at an EPICC site can join. Likewise, those 18 years or older who have been tested for COVID-19, whether they tested positive or negative, can participate in the online portion of the study, which includes self-collected blood specimens for selected participants.

The protocol was recently updated to also enroll COVID-19 vaccine recipients and will initiate recruitment upon approval, said Navy Capt. (Dr.) Timothy Burgess, program director of IDCRP, who oversees the study. Eligible beneficiaries who are interested in participating in EPICC can submit an online screening form to join.

“In addition, asymptomatic individuals with a high risk of exposure are also eligible for enrollment in EPICC, which includes health care workers and close contacts of cases,” said Burgess. “Particularly, health care workers who have received a COVID-19 vaccination will be an important population for studies to examine vaccine effectiveness and outcomes.”

Data from inpatient, outpatient, and online participants, including their clinical characteristics, comorbidities, the clinical course of their illness, treatment, immunology, and outcomes, is being collected for the study.

“Questionnaires are provided to enrollees to collect information on demographics, symptoms at initial presentation and chronic or persisting symptoms during follow-up, exposure history, and lifestyle factors,” said Burgess. “Clinical and research specimens collected from enrollees are examined using molecular, serological, and other immune assays in collaboration USU and non-USU partner laboratories.”

Initiated in March 2020, EPICC is expected to continue enrolling participants at least through March 2022, or for as long as needed to fill in the knowledge gaps related to this disease, explained Agan.

“Once enrolled, participants are actively followed for one year to fully capture specimens and data including chronic outcomes and sequelae and will be followed for up to four additional years through electronic medical record review,” Agan said.

EPICC is being conducted at 10 military medical treatment facilities throughout the United States:

  • Brooke Army Medical Center in Fort Sam Houston, Texas
  • Carl R. Darnall Army Medical Center in Fort Hood, Texas
  • Fort Belvoir Community Hospital in Fort Belvoir, Virginia
  • Joint Base Lewis-McChord, Washington
  • Naval Medical Center Portsmouth in Portsmouth, Virginia
  • Naval Medical Center San Diego in San Diego, California
  • Tripler Army Medical Center in Honolulu, Hawaii
  • William Beaumont Army Medical Center in El Paso, Texas
  • Womack Army Medical Center in Fort Bragg, North Carolina
  • Walter Reed National Military Medical Center in Bethesda, Maryland
Military health personnel wearing a face mask and shield speaking to a man who is wearing a face mask Navy Hospital Corpsman 3rd Class Michael A. Torrent conducts a pre-screening questionnaire prior to administering the COVID-19 vaccine as part of Operation Warp Speed at Walter Reed National Military Medical Center. (U.S. Navy photo by Ricardo Reyes)

By the first week of February, more than 1,600 active-duty service members and MHS beneficiaries had enrolled in EPICC, the majority of whom are being treated as outpatients, said Agan. Approximately half of the subjects with confirmed SARS-CoV-2 diagnoses included in EPICC are active-duty service members.

Some interesting observations the researchers found thus far are that the characteristics of hospitalized COVID-19 patients compared to those treated as outpatients has shown a higher proportion of comorbidities, with hypertension, diabetes, and obesity being most prevalent, said Agan. In fact, their findings have begun to identify why obesity is a risk factor for more severe disease.

They were also able to garner valuable insight into the risk of reinfection from a military health care worker enrolled in the study who was reinfected with a symptomatic case of COVID-19. 

“A median time to recovery has been identified as 14 days, with nine lost duty days among active-duty service members,” said Agan. “These findings not only support operational planning, but also provide an important baseline to evaluate the effectiveness of vaccines as uptake widens across the DOD.”

They also found that the antibody levels that cause immunity remain in individuals for more than six months post-infection and that there were no “seroreversions” after six months post-infection. Seroreversion is the loss of serologic reactivity, or the presence of a particular antigen in the blood, whether spontaneous or in response to therapy. 

“With ongoing concerns about the magnitude and duration of immunity post-infection, our findings were both surprising and a relief,” said Burgess.

The researchers hope the information on the effectiveness and safety of the vaccines will alleviate concerns and encourage individuals to be vaccinated. And as the vaccine rollout expands to more recipients, the study will benefit from recruiting participants among the growing population of vaccinated recipients.

“This will enhance our ability to evaluate vaccine effectiveness in the population and if other reports showing high levels of protection are confirmed, our work may help boost confidence among those who are less certain,” said Burgess. “We are excited about the ability of the EPICC study to answer key questions for patients, health care providers, and leadership to guide decisions as we steer through the coming months of this unprecedented and historic pandemic.

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Last Updated: July 11, 2023
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