NOV 17, 2016 1:38 PM PST

Why are women at a greater risk for Zika infection?

WRITTEN BY: Kara Marker
Scientists have found that the vaginal immune response is suppressed when infected with RNA viruses. The Zika virus is an RNA virus. So what does this mean for women exposed to the Zika virus?
 Council on Foreign Relations
From the Gladstone Institutes, researchers compared mice infected with Zika virus two different ways: systemically like when an individual is bitten with a mosquito, and via the vagina like when an individual has sex with someone infected with the virus. The immune system reaction is vastly different in each scenario, raising concerning for the health of women, especially pregnant women, exposed to Zika via sexual transmission.
 
"The dampened vaginal immune response is especially concerning, because it gives the virus more time to spread to the fetus if a woman is pregnant or becomes pregnant during the course of infection,” explained senior author of the recent study, Shomyseh Sanjabi, PhD.
 
During the study, the mice that were infected with Zika through the vagina were still infected after three days, when the mice infected with Zika systemically had already recovered from the infection. The scientists found that for the mice infected through the vagina, something was not happening that should have been to mount a healthy immune response. Infected cells normally release interferon first thing after being infected with the virus, fighting the infection but also warning adjacent cells of the virus’s presence, launching a full-on immune attack. Even after three days of infection, vagina-infected mice seemed to have produced zero interferon.
 
"Interferon is elicited as the first step in an immune response, and the fact that we barely detected it in the vagina was very alarming,” said first author Shahzada Khan, PhD. “Without interferon, the rest of the immune system cannot be triggered efficiently, making it extremely difficult for the body to fight viral infections."
 
However, once the infection reached the lymphoid tissue - about one week after the initial vaginal infection - the immune system kicked in high gear and began fighting the infection. Even after this step occurred, though, Zika virus never fully disappeared from the vagina.
 
The researchers also tried “priming” the vagina with an inflammatory drug, essentially giving the cells a quick start to trigger an immune response by releasing interferons. Following a Zika infection, the mice were protected, ridding themselves of the virus after two days.
 
"There is something unique going on in the female reproductive tract that makes women particularly vulnerable to RNA viruses," said Sanjabi. "Our next goal is to figure out why this is the case - whether it's a defense mechanism elicited by the pathogens themselves or an immunological loophole in the vaginal tissue."
 
Sanjabi’s study was recently published in the Journal of Experimental Medicine. Click here to read more about the Zika virus.
 

 
Source: Gladstone Institutes
 
About the Author
  • I am a scientific journalist and enthusiast, especially in the realm of biomedicine. I am passionate about conveying the truth in scientific phenomena and subsequently improving health and public awareness. Sometimes scientific research needs a translator to effectively communicate the scientific jargon present in significant findings. I plan to be that translating communicator, and I hope to decrease the spread of misrepresented scientific phenomena! Check out my science blog: ScienceKara.com.
You May Also Like
NOV 24, 2020
Immunology
Dirty Sheets Make Babies Healthier
NOV 24, 2020
Dirty Sheets Make Babies Healthier
Microbiologists have established that the development of infants’ immune systems is intricately linked to the dive ...
DEC 01, 2020
Immunology
Scar-Free Healing Starts With Mobilizing the Immune System
DEC 01, 2020
Scar-Free Healing Starts With Mobilizing the Immune System
Thanks to a new hydrogel biomaterial developed by researchers at Duke University, we are one step closer to the holy gra ...
DEC 23, 2020
Cell & Molecular Biology
Similarities Between Two Proteins May Impair One's Activity
DEC 23, 2020
Similarities Between Two Proteins May Impair One's Activity
Cytokines are a group of molecules that are involved in several processes including cell signaling and inflammation, the ...
DEC 29, 2020
Immunology
Cancer-Killing Viruses Enter in Stealth Mode, Penetrate Immune Barrier
DEC 29, 2020
Cancer-Killing Viruses Enter in Stealth Mode, Penetrate Immune Barrier
Viruses that when administered to patients preferentially attack and kill cancer cells, leaving normal tissues unscathed ...
MAR 14, 2021
Immunology
How Are Allergies Developed?
MAR 14, 2021
How Are Allergies Developed?
You might have experienced it yourself or met someone that can not eat a certain food or can not take a specific medicat ...
MAR 04, 2021
Infographics
All You Need to Know about COVID-19 Vaccines
MAR 04, 2021
All You Need to Know about COVID-19 Vaccines
After over a year lockdowns brought on by the pandemic, hopes for returning to something even similar to ' ...
Loading Comments...