Experimental Zika Virus Inoculation in a New World Monkey Model Reproduces Key Features of the Human Infection

Area of Science:

• Virology
• Primate Models
• Infectious Diseases

Background:

• Zika virus (ZIKV) poses significant public health risks, including fetal brain defects and neurological illness.
• An urgent need exists for a suitable animal model to study ZIKV transmission and pathogenesis.
• Current models lack comprehensive similarities to human ZIKV infection.

Purpose of the Study:

• To establish and characterize a marmoset model for Zika virus infection.
• To evaluate ZIKV transmission routes and host immune responses in non-human primates.
• To assess the utility of the marmoset model for preclinical testing of ZIKV countermeasures.

Main Methods:

• Experimental infection of male marmosets with a prototype ZIKV strain.
• Clinical monitoring and collection of various body fluids and tissues over a 3-month period.
• Re-challenge experiments with a contemporary ZIKV outbreak strain to assess protective immunity.

Main Results:

• Marmosets exhibited mild or asymptomatic ZIKV infection, mirroring human illness.
• ZIKV persisted longer in saliva and semen than in serum, indicating potential for oral and sexual transmission.
• Infectious ZIKV was detected in saliva, supporting oral transmission routes.
• Neutralizing antibodies and antiviral immune responses were generated.
• Re-challenge conferred protection and boosted immune responses.

Conclusions:

• The marmoset model closely resembles human ZIKV infection, including asymptomatic presentation and viral persistence in key body fluids.
• The model supports the potential for ZIKV transmission via the oral route.
• This primate model is valuable for evaluating the efficacy of ZIKV vaccines and therapeutics.