The World Health Organization has recently warned that the Zika virus is spreading fast in South America and approximately 4 million people could be at risk when the XXXI Olympics is held in Brazil on August this year.

This virus is being linked to around 4,000 recent cases of microcephaly in Brazil. If a newborn is affected with the virus, the baby stands the risk of having abnormally small head and brain.

The spread of this fearsome virus comes at the time when tens of thousands Olympic fans around the world are scheduled to descend on Brazil for the sports event that comes only once in four years.

This makes the event a possible springboard for the spread of the virus globally when Olympic visitors return home.

"For most people, the Zika virus is not a problem," says Dr. Beth Bell of the Centers for Disease Control and Prevention in an interview with Voice of America. "It can cause mild, flu-like symptoms, but the virus can also cause babies to be born with a serious condition called microcephaly," she explains. 

In a related event, there is a possibility that before the year ends, a vaccine to fight this virus could be ready for emergency use. This was announced Thursday by the lead developers of the vaccine, ahead of the time schedule set by U.S. officials.

"The first thing is to be ready for the worst," says Gary Kobinger, a Canadian scientist who was part of the team that developed a trial vaccine used in defeating the Ebola virus in Guinea.

He also stated that the vaccine is easy to produce and can be tweaked to high levels in just a short time. However, he did not mention when it will be commercially available.

According to the WHO, Zika virus was seen initially as just a mild risk to humans. However, it has spread quickly to be a public-health threat of "alarming proportions."