INCIDENCE OF LATENT VIRUS SHEDDING DURING SPACEFLIGHT (LATENT VIRUS)
Research Area: Immune System
Expeditions: 1, 2, 4, 5, 11, 13- 15
Principal Investigator(s): ● Duane L. Pierson, PhD, Johnson Space Center, Houston, Texas
RESEARCH OBJECTIVES
The Incidence of Latent Virus Shielding During Spaceflight (Latent Virus) study supports and
expands information on latent viruses—or those inactive in the human system—that can
reactivate in spaceflight such as a cold sore. Latent virus reactivation could be an important
threat to crew health during extended space missions, as crew members live and work in a
closed environment. Potential applications of this research include the development of a rapid
and sensitive diagnostic method for identifying crew members at increased risk of illness
because of viral infections. New technology from this investigation benefits both NASA and
commercial applications.
EARTH BENEFITS
The viral-specific saliva DNA test currently used for spaceflight investigations are applied to the
rapid diagnosis of herpes virus disease in clinics. These studies of latent virus reactivation in the
very healthy, superbly-conditioned flight crews provide new insight into stress, immunity, and
viral disease in the general population.
SPACE BENEFITS
This investigation helps determine the clinical risk of asymptomatic reactivation and shedding
of latent viruses to astronaut health and the need for countermeasures to reduce or eliminate
the risk. Stress-induced viral reactivation may also prove useful in monitoring early changes in
immunity prior to onset of clinical disease.
RESULTS
Saliva samples collected from crew members
traveling on the shuttle to and from the
International Space Station (ISS) have provided
valuable data for the Latent Virus investigation.
Epstein-Barr (EBV) and Varicella zoster (VZV)
viruses were studied and results indicate that these
latent viruses can become active under stressful
conditions such as spaceflight. The pattern and
amount of EBV shedding in the astronauts are likely
related to spaceflight conditions. The types, levels,
and combination of stresses experienced before,
during, and after flight, as well as the different
ways individuals cope with stress may result in
changes in the EBV shedding frequency. Healthy
astronauts from 3 shuttle missions along with
ground volunteers were also studied to determine
Electron micrograph of a Varicella-Zoster
Virus. Center for Disease Control and
Prevention image, Atlanta, Georgia.