Associated with grave birth defects, the Zika virus tearing across Latin America could eventually affect more than half of the world's population.
That's according to the London School of Hygiene & Tropical Medicine which agreed to an interview via email.
Although the current epidemic in the Americas is being spread by the Aedes aegypti mosquito, according to Jimmy Whitworth, the School's Professor of International Public Health:
"A number of mosquitos have been documented to carry the Zika virus. For example, the Aedes albopictus mosquito which resides in large parts of the U.S., southern Europe, and Asia is of particular concern because it's a competent vector for the virus."
It could therefore create large "outbreaks in the future."
His thoughts are echoed by the Pan American Health Organization, which expects the disease to spread "everywhere the mosquito is."
And, considering that Zika may have only arrived in Brazil 18 months ago via a single infected traveler who was bitten by a local mosquito, its capacity to spread at lighrening speed is quite alarming.
It has since exploded across 23 countries in the Americas.
"In the right conditions, with sufficient mosquitoes and closely packed humans, the virus can spread rapidly. Aedes aegypti, the main vector of Zika, is a domestic mosquito that can breed in any small deposit of water," says Martin Hibberd, Professor of Emerging Infectious Diseases at the School.
Climate change may have stoked the flames of this epidemic. After all, it started during the hottest year on record, and warmer temperatures dramatically speed up the breeding cycle of mosquitos.
That means that they breed more, bite more and spread more disease.
And, according to Dr Laith Yakob, the school's Lecturer in Disease Vector Biology, temperature plays a key role:
"There is some concern that the albopictus mosquito may spread the disease further because of its ability to thrive in more temperate climes. But, it is important to note that although some of the more temperate regions may well be permissive to mosquito survival, they may not be to the propagation of the virus itself. More research is required."
Like so many viruses such as Aids, Ebola, and Yellow fever, Zika originated in Africa.
Although the virus itself is of little concern, causing mild to non-existent symptoms such as a rash, itchy skin and red eyes, it wreaks havoc in pregnant women.
The virus attacks the brain of the foetus, creating babies with microcephaly - a very small underdeveloped head - and neurological problems.
And, even though there is no absolute proof that Zika is behind the recent surge in these birth defects, and outbreaks of Guillain-Barré syndrome, an auto-immune disease which causes temporary life threatening paralysis, the world's leading health authorities are close to certain that it is.
In fact, according to Whitworth, "few scientists doubt the link". Accordingly, he asserts that the "more important questions now are: how strong is the link, and are they any co-factors involved."
According to the latest W.H.O. report, Brazil normally has an average of about 160 cases of microcephaly every year. But over the past year, there have been well over 2,700 documented cases.
For more definitive proof, scientists are waiting for a large study of 5,000 pregnant women in Colombia to yield results. According to the WHO, the epidemic peaked in Colombia in early February, and most of those women are due to give birth over the next 2 months.
"Although there is a strong scientific consensus that Zika causes microcephaly and other neurological defects, the risk to women is less clear" says Whitworth.
Citing a recent study in French Polynesia, he says that the risk of the defect is about one in every 100 women infected with Zika during the first trimester", though concedes that "more research is needed."
A report in the Lancet concluded that first-trimester infections were the most dire.
But, in a smaller Rio de Janeiro study, even two fetuses which became infected at the later stages of pregnancy suddenly died upon contracting the virus.
Whitworth therefore concludes that the virus poses a risk to all pregnant women, regardless of trimester.
Moreover, "until recently it was thought that the only way Zika was transmitted was via mosquito bites. But, there are now reports of a small number of cases being transmitted sexually. So far, all reports are all of transmission from men to women" says Whitworth.
And, it's not only pregnant women and couples looking to conceive who need to worry about the virus: "As with microcephaly, the evidence that Zika can cause Guillain-Barré syndrome is mounting all the time" says Whitworth.
GBS causes temporary paralysis which requires hospitalization as the patient requires life support in order to keep breathing. Whitworth says:
"A recent study looking at the outbreak of Zika in French Polynesia estimated that 24 out of 100,000 people infected with Zika would develop GBS. If the link is proven, anyone living in, or travelling to, a country where Zika is present is at risk. But, thankfully it seems that the risk is very very small."
According to Whitworth, as Zika is only a mild disease, "the focus should be on preventing microcephaly in babies", not on preventing the disease itself.
And, as is the cases with most viruses, once infected scientists strongly suspect that one becomes immune, but "the jury is out on how long that immunity lasts," says Whitworth.
In a bid to be cautious, US health authorities advise infected women not to conceive for at least 2 months after contracting the virus, and men to abstain for at least 6 months as the virus stays in semen for longer.
"Pregnant women, or women wanting to get pregnant, should heed Public Health messages which include not travelling to areas with active Zika transmission unless it's essential," says Whitworth as there is currently no drug nor vaccine to tackle the virus.
Although the WHO has declared Zika an international public health emergency, there are no experimental treatments or vaccines in the pipeline that could be fast-tracked as was the case for Ebola.
Sanofi, the French drugs giant, is close to launching the world's first vaccine for dengue, and is "reviewing the possibility" of applying it to Zika. But, it has warned that "there are too many unknowns" to predict how long it would take.
The WHO says that there is some research into a potential Zika vaccine which they hope to accelerate. But it will take at least "12 months-plus" before a vaccine was possible.