NMRC Research Shows Antibodies Not Guarantee

SILVER SPRING, MD, UNITED STATES

04.15.2021

Courtesy Story

Naval Medical Research Command

SILVER SPRING Md. (NNS)--Researchers from Naval Medical Research Center (NMRC) found that antibodies produced after SARS-CoV-2 infections are largely protective against future infections but they are not a guarantee. Findings from theCOVID-19 Health Action Response for Marines (CHARM) study were published April 15, in the Lancet Respiratory Medicine Journal.

The study was conducted by NMRC in collaboration with the Icahn School of Medicine at Mount Sinai to examine how effective protective, detectable antibodies are in preventing future SARS-CoV-2 infections.

The CHARM study began in May 2020 with the Navy and Marine Corps working together to ensure military training could safely continue during the pandemic. It was the only study focused on young adults in groups settings at that time and the data collected has proven helpful in informing public health measures.

In order to mitigate the spread of the virus, the U.S. Marine Corps (USMC) implemented two separate quarantine protocols. The first was a two-week home quarantine followed by a USMC-supervised quarantine upon arrival for basic training.

To determine how widespread SARS-CoV-2, with and without symptoms, was among study participants during the quarantine period and transmission rates, researchers collected and tested specimen samples weekly to assess for the presence of antibodies.

“To determine if a person had been previously infected, we used two different tests to assess for the presence of antibodies, both of which are very specific for SARS-CoV-2, the virus that causes COVID-19, and will only be positive if a participant had been previously exposed to the virus,” Cmdr. Andrew Letizia, deputy director infectious disease directorate, NMRC. Researchers found that the presence of antibodies conferred an 82% reduction rate for future SARS-CoV-2 infections. Among the seropositive group, participants who became infected had fewer antibodies in general than those who were uninfected.

The next step for researchers is determining if re-infected people can infect other people. This is key to working towards herd immunity and life without masks.

Young adults, many of whom are asymptomatically infected and develop antibodies without known infection, can be a primary source of transmitting COVID-19 to more vulnerable populations. Evaluating the protection provided by antibodies against future SARS-CoV-2 infection is important for determining the need for vaccinating previously infected individuals in this age group.

“If we’re going to achieve herd immunity, we have to get enough people vaccinated,” Letizia said.

The CHARM study is ongoing and research teams will travel throughout the year to all locations the recruits, now Marines, are currently stationed.

NMRC's eight laboratories are engaged in a broad spectrum of activity from basic science in the laboratory to field studies at sites in austere and remote areas of the world to operational environments. In support of the Navy, Marine Corps, and joint U.S. warfighters, researchers study infectious diseases, biological warfare detection and defense, combat casualty care, environmental health concerns, aerospace and undersea medicine, medical modeling, simulation and operational mission support, and epidemiology and behavioral sciences.

• Date Taken: 04.15.2021
• Date Posted: 04.15.2021 11:14
• Story ID: 393917
• Location: SILVER SPRING, MD, US