Marines volunteering for a groundbreaking study on COVID-19's long-term effects on young people could help commanders better understand the risks of deploying both vaccinated and unvaccinated military personnel during the pandemic.
More than 460 Marines so far have volunteered to participate in the second portion of the COVID-19 Health Action Response for Marines -- or CHARM -- study. The study is open to nearly 3,000 Marines, now in the fleet or their military occupational specialty school, who participated in the first portion of the CHARM study during boot camp in South Carolina.
While the first part of the study required volunteers to complete questionnaires, give blood and saliva samples, and take a nasal swab, the new portion also includes a neurological assessment, a breathing test, and an electrocardiogram and ultrasound on their hearts.
Navy Cmdr. Andrew Letizia, the CHARM study's principal investigator, said there isn't much data about how young people have been affected by the sometimes-fatal COVID-19 illness, which has caused a global pandemic and killed more than two dozen troops. Between 10% and 15% of civilians infected with the virus have shown long-term health effects, but questions remain about how the illness affects young and otherwise-healthy people, he said.
"This follow-on study," Letizia said, "is designed to continue to support the medical readiness of the Marine Corps specifically -- and by extension our sister services, and ensuring that these Marines are safe to deploy."
The study examines both Marines who tested positive for COVID and those who didn't. The group also includes Marines in both of those categories who've gotten the COVID-19 vaccine and those who've declined it.
Letizia and his team are taking blood samples from Marines to test how their antibodies -- whether built up from a past COVID-19 infection or the vaccine -- respond to new variants of the illness in a lab.
"We want to make sure that individuals in our study continue to be making protective antibodies ... six, nine or even 12 months after they're originally infected," Letizia said. Marine Corps deployments typically last between six and nine months.
Researchers also want to know how the Marines' antibodies -- whether from past infections, the vaccine or both -- stand up to new strains of the virus, which vary by region. Strains prominent on the East Coast of the U.S. are currently different from those dominating on the West, and abroad other types are found.
"We want to better understand how well these Marines [might react] if they were to encounter one of the emerging variants or strains since they'll be deployed around the world," Letizia said.
The study will also examine whether a condition often referred to as "long-haul COVID" might be affecting the military community. The Centers for Disease Control and Prevention describe those symptoms that can linger for weeks after a COVID-19 infection as fatigue, heart palpitations, shortness of breath, headache, and joint or muscle pain, among other problems.
Chronic conditions in Marines, including cardiopulmonary or neurologic problems, are of concern, Letizia said, even if the Marines were asymptomatic -- or showed no signs of being infected with COVID-19. About two-thirds of the participants in the first portion of the study who tested positive for the virus were asymptomatic, he said.
Navy corpsmen are performing ultrasounds for the study on Marines' hearts using artificial intelligence technology developed by Caption Health. The tool allows people without formal ultrasound training to take high-quality images.
That's important since viruses such as COVID-19 can attack the heart and cause inflammation -- a condition called myocarditis, said Dr. Randolph Martin, Caption Health's chief medical officer who's also a cardiologist and Army veteran.
"This is really an attempt to look at those individuals that might have been exposed and get some baseline evaluation of their cardiac status for them," Martin said. "... It is a good way to look at the cardiac structure and function [to] see if there are any abnormalities that might be attributed to COVID exposure or other abnormalities. Then they can be evaluated further."
That's something that could prove useful beyond the pandemic to find previously undetected heart problems in troops, Martin added. The ultrasound technology is portable, and thus could be used in the field or on ships. It could also be used to assess potential recruits' hearts for abnormalities before they start training.
Caption Health's AI tool can also flag abnormalities that might need further attention, he said. So far, none of the findings flagged during the study have led any Marines to be sidelined from their duties, Letizia added.
The evaluation for the second portion of the CHARM study takes about 60 minutes. Since those eligible to participate have now left Parris Island for training schoolhouses or their assigned units and squadrons, Letizia and his team have taken their study on the road to major installations across the country.
Marines in California, Virginia and North Carolina have been given the chance to volunteer to participate in the new leg of the study and they're working to identify other duty stations.
More than 3,000 Marines participated in the first portion of the study. So far, Letizia said between 60 and 65% of those given the chance to opt into the second part of the study have volunteered.
As more older Americans get vaccinated, some states are reporting a rise in serious COVID-19 cases among young adults or those middle aged. The CHARM study gives a unique look at how younger cohorts could be affected by the disease long term.
"My job is really to help [commanders] operationalize the data in order to make some key decisions that ensure that our Marines and [Defense Department] service members as a whole are educated when it comes to informed decisions about obtaining a vaccine and that they can deploy safely," Letizia said.