Zika Virus Outbreak Update: Vaccine Could Be in Safety Trials by Fall

— -- The Zika virus outbreak continues spread throughout the Western Hemisphere, including in wide swaths of Central and South America, and concerns are growing for pregnant women because the mosquito-borne virus has been linked with a serious birth defect called microcephaly, characterized by an abnormally small head and brain.

Here are the latest updates about the outbreak, which the World Health Organization has deemed a "global health emergency."

NIH Official Says Zika Vaccine Trials May Start in Fall

Trials to find an effective vaccine for the Zika virus may start this summer or fall, according to Dr. Anthony Fauci, director of the National Institute for Allergy and Infectious Diseases.

Fauci, along with U.S. Centers for Disease Control and Prevention Director Dr. Tom Frieden, spoke to reporters today about the battle to contain the Zika outbreak. Fauci said NIAID is looking at multiple vaccine options and that a phase 1 trial to test Zika vaccine safety is expected to start in the coming months.

"I’m confident we'll get there," Fauci said of finding a vaccine. He cautioned that getting a vaccine approved by the U.S. Food and Drug Administration is likely at least a few years away.

"We may able to know if it’s effective or safe at end of 2017," Fauci said of early testing.

Both Fauci and Frieden said getting congressional funding for the vaccine research and to combat the spreading Zika virus is key. The White House has asked Congress for $1.8 billion in emergency funding to fight the Zika outbreak.

"We might find ourselves halfway through phase 1 and not be able to make a larger step to phase 2," Fauci said, describing a second trial that would test how effective a vaccine is against the virus. "If we don’t get the money the president asked for, it’s going to slow down a number of things."

Sexually Transmitted Zika Virus Reported in Florida for First Time

For the first time in Florida, the Zika virus has spread through sexual contact, according to the State Surgeon General and Secretary of Health Dr. John Armstrong.

Armstrong announced the news this week during his daily update on the Zika outbreak in the state.

At least 52 people have been diagnosed with the virus in the state, leading the governor to declare a state of emergency in 12 counties where people have been diagnosed with the virus.

In all cases except the newly reported sexually transmitted case, the virus was contracted while outside the U.S., health officials said.

The World Health Organization said this week that the virus appeared to spread more easily through sexual contact than previously believed. The virus has been spread through sexual contact in the U.S. at least one other time during this outbreak.

What Does the Virus Do?

Common symptoms of the Zika virus include fever, rash, joint pain and conjunctivitis, according to the CDC. Approximately one in five people infected with the virus show symptoms. Severe complications from the virus that require hospitalization are rare, according to the CDC.

The virus has also been associated with a rise of microcephaly birth defect cases.

The CDC is also investigating if a rare paralysis syndrome called Guillain-Barre is related to the virus. The syndrome is an immunological reaction that can also occur after other viral or bacterial infections.

How Is It Transmitted?

The virus is transmitted mainly through the bite of the Aedes aegypti species of mosquito. This is the same type of mosquito that spreads dengue fever. The Aedes albopictus species has also been identified as a potential carrier.

Before the current outbreak, the virus had been found mainly in tropical settings in Africa, Southeast Asia and the Pacific Islands. An outbreak of the disease in Brazil led to an alert by the Pan American Health Organization last May.

Health officials have also reported rare cases of transmission through blood transfusions and through sexual contact, including one case in Dallas, Texas.

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