The mosquito-borne Zika virus has been active for decades. Zika preventive vaccine research is ongoing investigating the effects of Zika virus infection on pregnancy outcomes, strategies for prevention, and infection effects on neurological disorders. However, there are no approved Zika vaccines available in the USA.
Clinical trials involving candidate DNA and purified inactivated virus vaccines showed all were safe and well-tolerated in small studies and all induced neutralizing antibodies, although these studies varied by vaccine candidate and dosing regimen. Previous study results suggest that a Zika vaccine can be developed.
There are several Zika vaccine candidates in various stages of a clinical study.
Zika Vaccine Candidates
TAK-426 (PIZV) is a purified, inactivated, alum-adjuvanted, whole Zika virus vaccine candidate. The vaccine being tested in a phase 1 study is called PIZV or TAK-426 adjuvanted with aluminum hydroxide. The Zika virus vaccine is being tested to provide safety and immunogenicity data to enable the vaccine to be further developed clinically.
Ad26.ZIKV.001 is a replication-incompetent human adenovirus serotype 26 (ad26) vector vaccine candidate. In phase 1 clinical trial, researchers found that 2 doses of Ad26.ZIKV.001 was safe, causing mild to moderate reactogenicity and induced persistent neutralizing antibody responses. The single-dose had lower peak antibodies but were durable after 1 year.
mRNA-1893 contains an mRNA sequence encoding for the structural proteins of the Zika virus.
ZPIV is a Zika virus vaccine candidate that consists of a purified formalin-inactivated Zika virus.
INO-A002 is a DNA-encoded monoclonal antibody (dMAb™) technology.
VLA1601 is a purified, inactivated, whole Zika virus vaccine candidate adsorbed on aluminum hydroxide (alum).
VRC5283 is a Zika Virus DNA Vaccine composed of a single closed-circular DNA plasmid that encodes with wild-type precursor transmembrane M and envelope proteins from the H/PF/2013 strain of ZIKV.
Zika Vaccine News
February 18, 2021 - The Center for Infectious Disease Research and Policy at the University of Minnesota, the University of Texas Medical Branch, an expert team of task force members from around the world, and the World Health Organization have developed a draft Zika virus (ZIKV) Research and Development Roadmap. The roadmap is a key component of the WHO’s R&D Blueprint, a global strategy and preparedness plan that allows the activation of R&D activities in advance of and during epidemics.
February 16, 2021 - The Zika virus candidate, Ad26.ZIKV.001, a replication-incompetent human adenovirus serotype 26 (ad26) vector, showed promising safety and immunogenicity in phase I clinical trial. Researchers say the vaccine warrants further development should the need reemerge.
October 29, 2020 - Genetic factors that reduce the placenta's capacity to protect a fetus from the Zika virus are described by Brazilian researchers in an article published in PLOS Neglected Tropical Diseases.
October 14, 2020 - Study published by The Lancet: Vertical transmission of Zika virus and its outcomes: a Bayesian synthesis of prospective studies.
August 7, 2020 - A new study describes the preclinical selection and development of a potent ZIKV vaccine from 9 constructs using SAM technology expressing various forms of the ZIKV prM-E antigen. This study identified one ZIKV SAM vaccine candidate, VRC5283, that provided complete protection from the ZIKV challenge in both mice and NHPs.
April 15, 2020 - Moderna's Zika vaccine mRNA1893 low dose levels were found very effective.
January 23, 2020 - Researchers at the CUNY Graduate School of Public Health and Health Policy (CUNY SPH) and the National School of Tropical Medicine at Baylor College of Medicine announced that they had developed a computer model representing the impact to a woman if she becomes infected with Zika, how it varies with pregnancy. The potential benefits of a vaccine to prevent Zika infection.
December 19, 2019 - U.S. NIH-developed Zika vaccine improves fetal outcomes in an animal model.
December 13, 2019 - Researchers have made significant advances in developing a novel vaccine against the Zika virus, which could potentially lead to global elimination of the disease.
December 11, 2019 - Study: NS1 DNA vaccination protects against Zika infection through T cell-mediated immunity in immunocompetent mice.
September 3, 2019 - Article: A Gorilla Adenovirus-Based Vaccine against Zika Virus Induces Durable Immunity and Confers Protection in Pregnancy.
January 17, 2019 - A Measles Virus-Based Vaccine Candidate Mediates Protection against Zika Virus in an Allogeneic Mouse Pregnancy Model.
November 2, 2018 - Zika Virus Vaccine Development: Progress in the Face of New Challenges.
November 28, 2017 - Takeda Pharmaceutical announced that its purified, inactivated, alum-adjuvanted whole Zika virus vaccine candidate (TAK-426) has progressed into a Phase 1 clinical trial.
Zika Virus Overview
Zika virus is spread mainly through the bite of an infected mosquito. Female mosquitoes can bite several people in a short period of time, meaning that a Zika-carrier has the potential to spread the virus rapidly. Until a Zika preventive vaccine becomes available, pregnant women should delay visiting Zika endemic countries, says the U.S. CDC.
Zika virus infection during pregnancy is a cause of microcephaly and other congenital abnormalities in the developing fetus and newborn. Zika infection in pregnancy also results in pregnancy complications such as fetal loss, stillbirth, and preterm birth. Zika virus infection is also a trigger of Guillain-Barré syndrome, neuropathy, and myelitis, particularly in adults and older children.
While Zika virus-associated congenital disabilities have been well-documented, it was unknown if most of the infants who were potentially exposed to Zika (90% to 95%) without developing Zika-associated congenital disabilities had a higher-than-baseline risk of neurodevelopmental abnormalities.
"Understanding the full spectrum of effects associated with congenital Zika virus exposure will help public health respond quickly to future outbreaks, prevent Zika virus infection whenever possible, and provide the most up-to-date clinical guidance for the care of infants and children with congenital Zika virus exposure," researchers concluded.
On February 16, 2021, PLOS published 'Estimating the Effect of Discontinuing Universal Screening of Donated Blood for Zika Virus in the 50 U.S. States, which concluded by saying 'A simulation study published in January 2019 estimated that serious complications due to transfusion-transmitted Zika (TT-Zika) were unlikely and that universal screening for Zika was not cost-effective during the first year of screening.'
Note: Zika vaccine content sources include, but are not limited to, the World Health Organization, the US Centers for Disease Control and Prevention, clinicaltrials.gov, and the Precision Vaccinations news network. And this content has been reviewed by healthcare providers.