Scientific background

What kind of mosquitoes transmit Zika?

The Aedes aegypti mosquito is known to transmit the Zika virus, and researchers believe the Aedes albopictus mosquito may also spread the virus.

What is microcephaly? How is it linked to the Zika virus?

Microcephaly is a condition in which a child’s brain fails to develop properly in the womb, often leading to diminished brain size, impaired cognitive ability, motor control problems, seizures and related symptoms. The condition has been found in some infants whose mothers were infected with the Zika virus during pregnancy. In April 2016, a link between the Zika virus and microcephaly was confirmed by the Center for Disease Control.

What are other potential complications that might be linked to the Zika virus?

In addition to microcephaly, conditions suspected of being associated with Zika include:

  • Guillain–Barré syndrome, which causes sudden muscle weakness and even paralysis in adults.
  • Myelitis, which is an infection of the spinal cord.
  • Meningoencephalitis, an inflammation of the brain and surrounding tissues, usually caused by infection.
These neurological effects have caused great concern and prompted the World Health Organization to form a Zika Emergency Committee to address the problem.

Why should pregnant women be concerned?

Pregnant women infected with the Zika virus can transmit the virus to the fetus. Additionally, infants of women who are infected with Zika during pregnancy have a higher risk than normal of microcephaly, which is a condition where the brain does not develop properly in the womb. A link between a Zika infection during pregnancy and microcephaly was confirmed in April 2016. Due to this risk, some countries have advised women to delay pregnancy until the Zika outbreak is over.

What is a flavivirus?

The flavivirus genus, which includes Zika, dengue, yellow fever, West Nile viruses and others – are viruses which are transmitted to humans by a mosquito or tick bite. The Zika virus is transmitted primarily by two kinds of mosquitos: the yellow fever mosquito (Aedes aegypti) and the Asian tiger mosquito (Aedes albopictus).

Can work on related diseases help fight Zika?

Closely related viruses may give clues that could help researchers fight Zika. This is one of the reasons why OpenZika includes “template” crystal structures of targets from related viruses in our virtual screening experiments against the Zika models. However, although Zika may look like dengue, subtle changes on the virus surface and in the viral enzymes could impact how antivirals or even vaccines may work. The mechanism for these viruses getting into cells and their effects can vary dramatically. The top computational results from OpenZika will thus be tested in “wet lab” experiments with the actual Zika virus, to verify which compounds can help fight Zika.

What is the history of the Zika virus?

The original description of the virus was published in 1952, although it was originally isolated in 1947 in Uganda, Africa. It was subsequently isolated from mosquitos in 1948 and from humans in 1952. Zika is a re-emerging, mosquito-transmitted virus that was relatively unknown until 2007, when it caused a major epidemic on Yap Island in Micronesia, followed by outbreaks in Oceania in 2013-2014. Following its introduction into Brazil in 2015, the virus has spread rapidly across the Americas.

What are the symptoms of Zika?

The symptoms of Zika are usually relatively mild, including fever, joint pains, rash, conjunctivitis (red eyes), headache, and/or swollen lymph nodes.

How is Zika diagnosed?

Zika virus can be diagnosed by performing specific blood serum tests during the first week after onset of symptoms. Additional antibody testing can be performed to confirm an initial diagnosis.

How is Zika transmitted?

Scientists have confirmed a number of different means of transmission, including:

  • Bite from an infected mosquito
  • Blood transfusion
  • Sexual transmission
  • Transmission from mother to fetus

Are there any existing treatments for the Zika virus?

There are currently no treatments for the Zika virus, and there is no vaccine. Because the disease’s symptoms are usually mild, it has not been widely researched until the most recent outbreak began in the Americas. Therefore, scientists are just beginning to understand the molecular structure of the viral components and the full implications of the disease.

Is there a Zika vaccine?

Because the Zika virus usually only has mild symptoms, and because it was not widespread until recently, there has been little research on a vaccine until the outbreak in Brazil began in 2015. Currently, there are several groups researching vaccines in India, Brazil and the United States, but no vaccine has been approved as of May 2016.

What is the difference between a vaccine and an antiviral drug?

A vaccine is administered before a person becomes infected. Vaccination usually consists of one or several shots which stimulate the immune system to protect against subsequent exposure to the virus.

Antiviral drugs are used when a patient is currently infected with the virus. They generally work by blocking the activity of the proteins that the virus uses to replicate itself or to infect other cells. These drugs must be taken by an infected patient multiple times, until the virus is destroyed.

Are there other research efforts to fight Zika?

There are other efforts to fight the Zika virus throughout the world, most involving research into the atomic structure of the virus itself (or its individual components) and work on potential vaccines, based on viruses that are thought to be similar in structure to Zika. Organizations such as the World Health Organization, the Ministry of Health in Brazil, the Oswaldo Cruz Foundation (Fiocruz), and the Centers for Disease Control (U.S. CDC) are heavily involved in publicizing and supporting these efforts, and in encouraging researchers to share their data. Limited funding makes many research efforts difficult.

How is this project different from other Zika research efforts?

The OpenZika project is searching for potential antiviral drugs to combat the virus, whereas many other projects are looking for a vaccine or are studying the structure of the Zika virus itself. The exact, atomic scale structures of most of the proteins that play a key role in the Zika virus lifecycle have yet to be determined (by experiments called “X-ray crystallography”). Until then, scientists will use approximate structures derived from a process called “homology modeling.” This involves using the genetic information for the Zika proteins and looking for very similar target proteins from other organisms, such as the dengue virus, for which some of the protein structures are known at atomic detail. These known structures (called “templates”) are then used as the basis to develop models of the targets that likely resemble the Zika proteins. As scientists learn more about the structure of the Zika virus, we and they will be able to focus on the target proteins that are most crucial to finding antiviral drugs.

What efforts are there to control the mosquitos that transmit the Zika virus?

Countries in South America and Central America have launched plans to contain and eliminate mosquitos through widespread use of insecticides, mosquito traps, bedding nets, window screens, and other measures. In the United States, similar measures are being planned under the direction of the Centers for Disease Control. These measures are helpful, but can be limited by the fact that Aedes mosquitoes tend to hide in homes, they generally feed on humans during the day, and most types of mosquitoes are becoming increasingly resistant to many insecticides.

Where can I learn more about Zika?

World Health Organization:


Centers for Disease Control and Prevention:

National Institute of Allergy and Infectious Diseases:

U.S. Food and Drug Administration: