# Vertical Transmission of Zika Virus in Pregnant Olive Baboons FollowingVaginal Infection

> **NIH NIH R21** · UNIVERSITY OF OKLAHOMA HLTH SCIENCES CTR · 2020 · $181,250

## Abstract

PROJECT SUMMARY
Zika virus (ZIKV) infection in pregnancy is linked to a spectrum of fetal anomalies including microcephaly and
other CNS lesions. Male-to-female sexual transmission of ZIKV is well documented. ZIKV transfers to semen
and persists much longer vs. blood. Prolonged detection of ZIKV in the vagina and cervical mucus has been
noted in humans. Vaginal ZIKV infection of non-pregnant macaques leads to prolonged infection of the female
reproductive tract and systemic infection. Thus, the vagina appears to be a favorable environment for ZIKV
propagation and infection. The olive baboon's (Papio anubis) similarity to humans in terms of genetics, size,
reproductive physiology, placentation and immune repertoire makes this primate an excellent translational
model for studying ZIKV infection during pregnancy. Our team has flavivirus experience with the baboon. Our
preliminary data show that subcutaneous (sc) ZIKV inoculation during pregnancy can lead to vertical ZIKV
transfer to the fetal CNS. We hypothesize that vaginal inoculation of ZIKV infected semen in pregnant
baboons will result in 1) prolonged ZIKV persistence in the CV tract and dissemination to the local urogenital
lymphatics, including targeting of dendritic cells, macrophages and lymphocytes, enhancing ZIKV transfer to
the uterus, 2) activation of a CV mucosal immune and inflammatory response including immune cell migration
(monocyte, neutrophil, T cell) into CV tissue, 3) enhanced placental ZIKV infection resulting from enhanced
ZIKV infection of the uterus via urogenital lymphatics and/or ZIKV ascension through the cervical canal to the
intrauterine compartment and 4) enhanced vertical transmission of ZIKV with a more severe fetal CZS
pathology and/or pregnancy loss. We will determine the effect of vaginal inoculation of pregnant baboons with
ZIKV-infected semen during early- (50 days gestation, dG), and mid- (90 dG;) gestation on Aim 1) persistence
and propagation of ZIKV in the CV tract and spread to the local urogenital lymphatic system, Aim 2) CV innate
and adaptive immune responses (immune cell recruitment into CV tissue, CV inflammation, mucosal IgA
response) and Aim 3) ZIKV infection and pathology of uterus and vertical transmission placenta and fetus. We
will infect early- (50 days gestation [dG]), and mid- (90 dG; term ~181 dG) gestation baboons representing
unique periods of primate CNS development with potentially different CNS outcomes. ZIKV infection in early to
mid-gestation is linked to most severe fetal CNS outcome in humans. Pregnancies will be terminated near term
(170+/1 dG) for tissue collection in one cohort and at 28 days post-onset of maternal ZIKV viremia in a second
cohort allowing both acute (cellular/tissue targeting) and chronic maternal-fetal pathological effects of ZIKV to
be examined. We will compare outcomes from vaginal infection to our ongoing project using sc route of
inoculation as well as to age-matched control pregnancies.

## Key facts

- **NIH application ID:** 9901598
- **Project number:** 5R21HD096240-02
- **Recipient organization:** UNIVERSITY OF OKLAHOMA HLTH SCIENCES CTR
- **Principal Investigator:** DEAN MYERS
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $181,250
- **Award type:** 5
- **Project period:** 2019-03-26 → 2022-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9901598

## Citation

> US National Institutes of Health, RePORTER application 9901598, Vertical Transmission of Zika Virus in Pregnant Olive Baboons FollowingVaginal Infection (5R21HD096240-02). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/9901598. Licensed CC0.

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