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Clinical trials on a vaccine for Zika virus could start this year, U.S. health official says
WHO estimates 3 million to 4 million cases of Zika possible in Americas in 12-month period
(CNN) —
The Zika virus “is now spreading explosively” in the Americas, the head of the World Health Organization said Thursday, with another official estimating between 3 million to 4 million infections in the region over a 12-month period.
“The level of concern is high, as is the level of uncertainty,” Dr. Margaret Chan, WHO’s director-general, told her organization’s executive board members. “We need to get some answers quickly.”
Five things you need to know about Zika
The lack of any immunity to Zika and the fact that mosquitoes spreading the virus can be found most “everywhere in the Americas” – from Argentina to the southern United States – explains the speed of its transmission, said Dr. Sylvain Aldighieri, an official with the WHO and Pan American Health Organization.
Aldighieri gave the estimate for Zika infections (including people who do not report clinical symptoms) based on data regarding the spread of a different mosquito-borne virus – dengue. He acknowledged the virus is circulating with “very high intensity.”
Some 80% of those infected with the Zika virus don’t even feel sick, and most who do have relatively mild symptoms such as a fever, rash, joint pain or pink eye. But there are major worries about the dangers pregnant women and their babies face.
Chan said that, where the virus has arrived, there’s been a corresponding “steep increase in the birth of babies with abnormally small heads and in cases of Guillain-Barre syndrome.” Having small heads can cause severe developmental issues and sometimes death. Guillain-Barre is a rare autoimmune disorder that can lead to life-threatening paralysis.
The WHO’s Dr. Bruce Aylward cautioned there was no definitive link between Zika and these disorders but sees a legitimate reason for concern. The Centers for Disease Control and Prevention’s Dr. Anne Schuchat said there is a “strong” suggestion they are connected.
Complete Zika virus coverage
While studies are underway to determine any links, millions of people live in areas with real fears about what this virus can do.
After first being detected in 1947 in a monkey in Uganda, Zika was most often found along the equator from Africa into Asia. Nine years ago, new cases popped up in islands in the Pacific Ocean.
The children of Zika: Babies born with disorder linked to virus
Last year, the virus made its way to the Americas – with devastating results.
Since Brazil made its first discovery of Zika in May, the number of cases there and elsewhere in the Americas has grown exponentially. The virus had been thought to be relatively harmless over the long term, but that view changed late last year.
Health authorities began to suspect a connection between Zika and neurological ailments, especially in fetuses and newborns. Brazil alone has reported more than 4,000 cases of microcephaly – a neurological disorder resulting in the births of babies with small heads – in infants born to women infected with Zika while pregnant.
Map: Tracking Zika virus
“Zika is not a new virus,” the CDC’s Schuchat said. “But what we are seeing in the Americas is new.”
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MOHD RASFAN/AFP/Getty Images
A pest control worker fumigates a school corridor on the eve of the annual national Primary School Evaluation Test in Kuala Lumpur on Sunday, September 4. Malaysia reported its first locally transmitted Zika case on September 3.
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A banner about Zika virus is seen as ferry passengers arriving from Singapore get in line at the immigration check on September 4, in Batam, Indonesia.
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Alan Diaz/AP
A banner is flown over the South Pointe Park area, Tuesday, September 6, in Miami Beach, Florida.
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A pest control worker fumigates drains at a local housing estate where the latest case of Zika infections were reported on Thursday, September 1, in Singapore.
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Florida Gov. Rick Scott and Florida Surgeon General Dr. Celeste Philip address the media gathered at the Miami-Dade County Department of Health as they announce five cases of Zika in a 1.5 mile area of Miami Beach on Friday, August 19, in Miami, Florida.
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Brazil's interim President Michel Temer, center right, meets with officials during Temer's first visit to the Olympic Park on Thursday, June 14, in Rio de Janeiro. The Rio 2016 Olympic Games commence August 5 amid a political and economic crisis in the country along with the Zika virus outbreak.
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Rio 2016 Chief Medical Officer Joao Grangeiro, Municipal Secretary of Health Daniel Soranz and Sub-secretary of the State for Health and Surveillence Alexandre Chieppe field questions from the media during an International Media Briefing to address the Zika virus on Tuesday, June 7, in Rio de Janeiro.
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A health worker fumigates an area in Gama, Brazil, to combat the Aedes aegypti mosquito on Wednesday, February 17. The mosquito carries the Zika virus, which has suspected links to birth defects in newborn children. The World Health Organization expects the Zika outbreak to spread to almost every country in the Americas.
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OSWALDO RIVAS/REUTERS/Newscom
A man places a mosquito net over a bed at a home for the elderly in Masaya, Nicaragua, on Thursday, February 11.
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Fernando Vergara/AP
An Aedes aegypti mosquito floats in stagnant water inside a tire at a used tire store in Villavicencio, Colombia, on Thursday, February 4.
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A health worker fumigates an area in Caracas, Venezuela, on Tuesday, February 2.
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A lab worker exposes his arm to Aedes aegypti mosquitoes during testing at the Roosevelt Hospital in Guatemala City, Guatemala, on Monday, February 1.
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Felipe Dana/AP
Tainara Lourenco sits inside her home in Recife, Brazil, on Friday, January 29. Lourenco, five months pregnant, lives at the epicenter of Brazil's Zika outbreak. The Zika virus has been linked to microcephaly, a neurological disorder that results in newborns with small heads and abnormal brain development.
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Dr. Angela Rocha shows brain scans of a baby born with microcephaly at the Oswaldo Cruz Hospital in Recife on Thursday, January 28.
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Alice Vitoria Gomes Bezerra, a 3