The first live-attenuated vaccine candidate completely protects against Zika infection

The first live-attenuated Zika vaccine still in the development stage completely protected mice against the virus after a single vaccination dose, according to new research from The University of Texas Medical Branch at Galveston and Instituto Evandro Chagas at the Ministry of Health in Brazil. The findings are currently available in Nature Medicine.

While a Zika infection typically results in mild or symptom-free infections in healthy adults and children, the risk of microcephaly and other diseases in the developing fetus is an alarming consequence that has created a worldwide health threat. Pregnant women who are infected with the Zika virus but never display any disease symptoms may still give birth to a baby with microcephaly.

An effective vaccine is urgently needed for women of childbearing age and travelers to areas where the virus has been reported. Since Zika virus could also be sexually transmitted, prevention of men from infection through vaccination could also halt Zika transmission and diseases.

Rapid and promising progress has been made toward a Zika vaccine. These developing vaccines have been made from an inactivated version of the Zika virus or subunits of the virus; these vaccine candidates have been shown effective in mice and nonhuman primates.

"We chose to pursue a vaccine made from live virus that has been sufficiently attenuated, or weakened, to be safe, and is able to illicit robust immune response to protect us from Zika virus infection. Such live-attenuated vaccine has the advantage of single-dose immunization, rapid and strong immune response and potentially long-lived protection," said UTMB's Pei-Yong Shi, senior author and the I.H. Kempner professor at the Department of Biochemistry and Molecular Biology. "A successful vaccine requires a fine balance between efficacy and safety - vaccines made from attenuated live viruses generally offer fast and durable immunity, but sometimes with the trade-off of reduced safety, whereas inactivated and subunit viruses often provide enhanced safety but may require several doses initially and periodic boosters. Therefore, a safe live-attenuated vaccine will be ideal in prevention of Zika virus infection, especially in developing countries."

To create the vaccine, the researchers engineered the Zika virus by deleting one segment of the viral genome. A similar approach has successfully been used to develop a dengue virus vaccine, which is currently in phase three clinical trials.

Shi explained that the data indicate that the vaccine the team is developing has a good balance between safety and efficacy. A single immunization with the vaccine candidate produced strong immune responses and prevented the virus from infecting mice at all.

"Safety is a major hurdle when developing a live-attenuated vaccine. Our Zika vaccine showed promising safety profile in mice when compared with clinically approved live-attenuated vaccines, such as the yellow fever vaccine," Shi said.

"Vaccines are an important tool for preventing Zika virus transmission and microcephaly," said Pedro F. C. Vasconcelos, medical virologist and present director of the Evandro Chagas Institute and co-author. "This vaccine, the first live-attenuated vaccine for Zika, will improve the public health efforts to avoid the birth defects and diseases caused by Zika in countries where the virus is commonly found. The initial target of this vaccine is women of childbearing age, their sexual partners and children less than 10 years old.

This work was supported by UTMB, The University of Texas System, the Centers for Disease Control and Prevention, the Pan American Health Organization and the National Institutes of Health.

Chao Shan, Antonio E Muruato, Bruno T D Nunes, Huanle Luo, Xuping Xie, Daniele B A Medeiros, Maki Wakamiya, Robert B Tesh, Alan D Barrett, Tian Wang, Scott C Weaver, Pedro F C Vasconcelos, Shannan L Rossi, Pei-Yong Shi.
A live-attenuated Zika virus vaccine candidate induces sterilizing immunity in mouse models.
Nature Medicine (2017), doi: 10.1038/nm.4322.

Most Popular Now

FDA approves first biosimilar for the treatment of…

The U.S. Food and Drug Administration today approved Mvasi (bevacizumab-awwb) as a biosimilar to Avastin (bevacizumab) for the treatment of multiple types of cancer. Mvas...

Merck set to join forces with Project Data Sphere …

Merck, a leading science and technology company has announced that it will enter into a strategic collaboration with Project Data Sphere LLC, an independent, not-for-prof...

FDA approval brings first gene therapy to the Unit…

The U.S. Food and Drug Administration issued a historic action today making the first gene therapy available in the United States, ushering in a new approach to the treat...

Novartis appoints Bertrand Bodson as Chief Digital…

Novartis announced today that Bertrand Bodson, Chief Digital and Marketing Officer for Sainsbury's Argos, has been appointed to the new role of Chief Digital Officer, rep...

Boehringer Ingelheim Pharmaceuticals, Inc. receive…

Boehringer Ingelheim Pharmaceuticals, Inc. has announced that the U.S. Food and Drug Administration (FDA) approved CyltezoTM, a biosimilar to Humira®*, in a pre-filled sy...

Amgen and Humana partner for improved health outco…

Two of the nation's leading health organizations, health and well-being company Humana Inc. (NYSE: HUM) and biotechnology company Amgen (NASDAQ:AMGN), have teamed up to i...

This is how belly fat could increase your cancer r…

It's been well established that obesity is a contributor to cancer risk, but how it actually causes cancer is still a question that hasn't been fully explained. A new Mic...

Asthma medicine halves risk of Parkinson's

Parkinson's disease is a chronic disease with unknown causes. The disease destroys the brain cells that control body movements. Shivering, stiff arms and legs and poor co...

Tezepelumab significantly reduced asthma exacerbat…

AstraZeneca and Amgen Inc. (Amgen) announce results from the PATHWAY Phase IIb trial of tezepelumab that showed a significant reduction in the annual asthma exacerbation ...

Boehringer Ingelheim initiates Phase IIa study of …

Boehringer Ingelheim and pharmaceutical company Pharmaxis (ASX: PXS) announce that Boehringer Ingelheim has initiated a European and North American Phase IIa trial in NAS...

Victoza® reduces the risk of major cardiovascular …

A new analysis of the landmark LEADER trial shows that Victoza® (liraglutide) reduced the risk of major cardiovascular (CV) events in people with type 2 diabetes at high ...

Extended treatment with Brilinta reduces risk of c…

AstraZeneca today announced results from a new sub-analysis of data from the Phase III PEGASUS-TIMI 54 trial demonstrating a 29% risk reduction in CV death (p=0.0041) fro...

Pharmaceutical Companies

[ A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Z ]