For more than a year one third of the world has been highly concerned about the Zika virus outbreak and Splice has covered amazing achievements regarding Zika infection. These days it is one of the main newspaper topics because of the upcoming Rio de Janeiro Summer Olympics in Brazil, the country where most of the cases of Zika infection were reported.
Zika virus (ZIKV) is mainly transmitted by Aedes mosquitoes and it can cause severe brain damage in infants of pregnant women such as microcephaly and very common mild, short-lived symptoms in adults that can also result in more serious neurologic conditions such as Guillain-Barré syndrome (GBS).
Two weeks ago a first report on vaccine protection against the Zika virus was published in Nature magazine. A paper was written by researchers from University of São Paulo in Brazil, Harvard Medical School and Walter Reed Army Institute of Research. They reported first vaccines to effectively protect mice against the Zika infection after a single dose injection.
We are actually talking about two different vaccines, one being a subunit vaccine, which includes only a part of the virus, and the other a purified inactivated virus vaccine, where the whole virus is used and inactivated by chemicals or heat. Such technology was already used for many other diseases such as flu, polio or Japanese encephalitis, where about 1 in 4 cases are reported to be fatal because of the inflammation of the brain. Despite the fact that this vaccine technology has been used for many years, the main reason for its use is a superior safety profile. This is especially important factor when the infected patients are pregnant women. The main idea is to develop a vaccine that would be given to young women regularly, so they would develop immunity before their childbearing years (1, 2, 3).
The whole research took only five months, from the beginning of the work to publishing a scientific paper. The reason for this lies in good collaboration amongst different institutes and pharmaceutical companies, whose conduct of research was really exemplary. However, the clinical trial still has to be carried out. According to the researchers it will take at least three additional years before the actual vaccines reach the market (1, 2).
Nevertheless, the discovery makes us more optimistic when fighting dreadful epidemic. When fast and affordable diagnostic tests for Zika virus detection will be available as well, we will be able to limit the occurrence and spreading of the infection.
Blazka Orel, MSc, BioSistemika LLC
Science in the news: A Tale of Two Vaccines: Zika Vaccines Show Promise in Mice
- Nature: Vaccine protection against Zika virus from Brazil
- The Wall Street Journal: Sanofi Teams Up With U.S. Army on Zika Vaccine
- Center for Disease Control and Prevention: Japanese Encephalitis