“

zikaimage.pngIndia is among the five countries that are working on developing vaccine to protect against Zika virus, the World Health Organisation has said. As many 23 projects are being worked on by 14 vaccine developers in the US, France, Brazil, India, and Austria. As the vaccine will be used to protect pregnant women or women of child-bearing age, it must meet an extremely high standard of safety, WHO Director General Margaret Chan said at the United Nations. WHO estimates that at least some of the projects will move into clinical trials before the end of this year, but several years may be needed before a fully tested and licensed vaccine is ready for use. However, several scientists have warned that the first explosive wave of spread may be over before a vaccine is available. But all agreed that development of a vaccine is imperative.

More than half of the worldâÂÂs population lives in an area where the Aedes aegypti mosquito is present. The world was alerted to the first appearance of Zika in the Western Hemisphere on 7 May 2015, when Brazil confirmed that a mysterious outbreak of thousands of cases of mild disease with rash was caused by the Zika virus. The absence of population immunity gives the virus license to spread rapidly and behave in possibly unexpected ways, the WHO statement said. At the time of the May announcement, the disease looked reassuringly mild, with no hospitalizations or deaths reported. In July, Brazil reported an increase in cases of Guillain-Barré syndrome, followed by an unusual increase in microcephaly among newborns which were reported to WHO in late October. The possibility that a mosquito bite could be linked to severe fetal malformations alarmed the public and astonished scientists, WHO has said.

The association with Guillain-Barré syndrome and other severe disorders of the central nervous system has expanded the risk group well beyond women of child-bearing age. “”We now know that sexual transmission of the virus occurs. In less than a year, the status of Zika has changed from a mild medical curiosity to a disease with severe public health implications,”” the statement said. A pattern has emerged in which initial detection of virus circulation is followed, within about three weeks, by an unusual increase in cases of Guillain-Barré syndrome. Detection of microcephaly and other fetal malformations comes later, as pregnancies of infected women come to term. In the current outbreak, Brazil and Panama have reported microcephaly. Colombia is investigating several cases of microcephaly for a possible link to Zika.

In other countries and territories, the virus has not been circulating long enough for pregnancies to come to term. To date, 12 countries and territories have now reported an increased incidence of Guillain-Barré syndrome or laboratory confirmation of Zika infection among GBS cases. Additional effects on the central nervous system have been documented, notably inflammation of the spinal cord and inflammation of the brain and its membranes. The virus is currently circulating in 38 countries and territories. On present knowledge, no one can predict whether the virus will spread to other parts of the world and cause a similar pattern of fetal malformations and neurological disorders. If this pattern is confirmed beyond Latin America and the Caribbean, the world will face a severe public health crisis, the WHO has warned.”