Zika is the name of a fear especially to the women who are pregnant as there is no medicine for treating Zika virus. Scientists have been trying heart and soul for few years to invent a vaccine for Zika. Good news is that they are much closer to develop a vaccine for Zika virus.
Today researchers have released a study in the journal ‘mBio’, speak that they have created a clone of Zika virus. The scientist hopes that this new invention might help in the design and production of an effective vaccine.
The Zika virus was first identified almost 7 years ago, in Uganda. Over the last few months, however, it has rarely been out of the news.
Zika is spread by the bite of a mosquito and can also be passed on through sexual intercourse. Mainly, pregnant women can pass the virus onto their fetus,causing birth defects which are called microcephaly.
Before present situation, Zika had only circulated in a small geographical area,predominantly affecting primates.
In Brazil, in early 2015, the small local virus became an epidemic. From there it spread through South and Central America. But in February 2016, the World Health Organization (WHO) declared the Zika pandemic a public health emergency.Five months on, the United States Centers for Disease Control and Prevention(CDC) documented the first cases of infection in residents of Florida.
Presently,there is no vaccine for Zika and, consequently, medical researchers are pooling their resources in order to design one.
The problems which is facing by the researchers with Zika virus
Zika virus behavior is notoriously unpredictable, making them very difficult to stop. Zika is a member of the Flavivirus group, a group that includes yellow and dengue fever.
The Flaviviruses have a single strand of RNA and have proven very challenging to manipulate or clone. As DNA technology has advanced, reverse genetics has allowed scientists to examine single-stranded RNA using viral complementary DNA (cDNA) - a double-stranded DNA created from the virus' single-stranded genome.
The process relies on growing the virus inside a bacterium; however, Zika's toxicity to bacteria has previously been a substantial stumbling block.
Because of the inherent difficulties, a team of researchers at the National Institutes of Health, led by molecular biologist Alexander Pletnev,have made it their aim to create a live, attenuated vaccine similar to those already in use for yellow fever, Japanese encephalitis, and polio.
Pletnev's group had earlier successes with similar challenges; they created a vaccine for
West Nile virus, which is currently being trialed; they also worked on vaccines for St. Louis and Japanese encephalitis.
"Our goal is to create long-term immunity after one short immunization," says study leader and molecular biologist Alexander Pletnev, at the National Institute of Health's National Institute of Allergy and Infectious Diseases in Bethesda, Maryland.
The event for invention of a Zika vaccine
Pletnev,working alongside a team from the University of Texas and the U.S. Food and Drug Administration, started their work with a viral strain taken from an infected, febrile patient in Brazil.
The investigators managed to grow the strain within Escherichia Coli. To prevent Zika from destroying the bacterium, they reduced its toxicity and improved its stability by adding in trons (non-coding DNA) to the viral cDNA genome.
As the resulting clone named ZIKV was examined, it showed fewer genetic variability than the original virus; additionally, ZIKV was found to be attenuated, in other words, much less virile.
The new clone was further tweaked by the team so that it could be grown in Vero cells,which are derived from the kidneys of African green monkeys and commonly used when manufacturing human vaccines.
ZIKV was shown to replicate in various types of tissue, including placental and brain tissue - both of which are particularly sensitive to Zika attack. Theteam has already begun trials on mice using the cloned virus. Pletnev is encouraging other teams of scientists to use the ZIKV clone in their own studies in the hope that a vaccine for Zika can be designed as quickly as possible.
Though the scientists have not yet created a Zika vaccine, having a reliable model will assit biologists develop and test interventions designed to stem the pandemic. With an open invitation for other researchers to use ZIKV, advancement is likely to be swift.
Further a team from the University of Texas Medical Branch at Galveston was able to genetically engineer Zika, so researchers can now make the virus in test tubes and on Petri dishes,according to a study published Monday.
Lead author Pei-Yong Shi said his team's man made Zika means scientists can study and adapt the virus to develop a vaccine. It could also be used to test the efficacy of their own vaccines.
The team was able to infect mosquitoes with the cloned virus as well as mice, which went on to develop neurological diseases.
"What we've created is something that is reproducible, meaning that batches of this virus can be made in large quantities," Shi said.
The day is not so far when scientists will be succeed to develop the Zika vaccine and will help people for fighting against Zika and it will be disappeared from the planet. So the best wishes for the noble researchers who are involve with the study.