Zika virus unlikely to infect same person twice, says new study

WASHINGTON: People infected with Zika may not be susceptible to the virus again, according to new research which found that the infection provides excellent protection against reinfection.

"This means people infected during this current epidemic will likely not be susceptible again," said Stephen Higgs, director of the Biosecurity Research Institute at Kansas State University in the US.

"When a large proportion of the population is protected - known as herd immunity - the risk of future epidemics may be low," said Higgs.

"The research shows that infection provides excellent protection against reinfection," he said.

The findings also show that Zika virus is present in the blood very early during infection and remains in some tissues for a long time but is only briefly present in other tissues.

The researchers produced Zika virus at the Biosecurity Research Institute and provided it to collaborators to support studies performed at several other laboratories.

The collaboration helped them to better understand the dynamics of Zika viral infection, replication and shedding.

Zika RNA was detected in blood plasma as early as one day after the infection.

It also was detected in saliva, urine, cerebrospinal fluid and semen, and was briefly detected in vaginal secretions, researchers said.

They found that Zika RNA cleared from blood plasma and urine within 10 days, but viral RNA was detectable in saliva and seminal fluids until at least three weeks after Zika virus was no longer present in the blood.

During early and late stages of infection, Zika RNA was detected in tissues, including the brain and male and female reproductive tissues.

The researchers also discovered better models for improving Zika virus research and more quickly testing vaccines.

The finding was published in the journal Nature Medicine.