How to Prevent the Zika Virus

While the Zika virus usually only causes mild, self-limiting illness, the transmission of the virus during pregnancy can be serious and lead to a rare birth defect known as microcephaly. Because there is neither a vaccine nor treatment for the Zika virus, the only way to prevent infection is to avoid mosquito bites if traveling to or living in an area where the Zika risk is high.

Moreover, if you are in those areas while you are pregnant, you would need to either use condoms every time you have sex or abstain from sex until your doctor tells you otherwise.

Preventing Mosquito Bites

The Zika virus is primarily spread by the Aedes aegypti mosquito, a strain prevalent in tropical and subtropical regions throughout the planet. Mosquitoes that spread Zika bite during the day and night. The mosquito can be recognized by white markings on its legs and a marking on its back in the shape of a lyre.

In the northern hemisphere, the season could start as early as April and end in November when temperatures drop below 50 degrees Fahrenheit. In the southern hemisphere, the opposite would be true, with the season running from September through May.

The Aedes aegypti mosquito can be found in most equatorial countries but is associated with large-scale infestations in South America, Central America, and the Caribbean, Central and East Africa, India, Southeast Asia, and northern Australia. In the U.S., the mosquito is most commonly seen on the Gulf Coast running from Texas to Florida, though there is no current reported transmission of the virus in these areas.

Preventing Sexual Exposure

Avoiding Zika during pregnancy requires a two-prong approach: preventing mosquito bites and avoiding exposure during oral, vaginal, or anal sex.

If you are pregnant, it is best to avoid traveling to countries where the virus is endemic. If your partner has just returned from such an area, there are several things you both can do to protect yourself.

If your partner has or develops Zika symptoms, testing should be sought from the municipal or state health department. Neither preconception testing nor the testing of an asymptomatic partner is currently advised.

If you have been trying to conceive, you may want to delay your plans until a doctor or infectious disease specialist tells you otherwise. Research has shown that the Zika virus can persist in semen for as long as 188 days following symptoms. During this time, if the virus is passed to the mother, it can lead to a potentially devastating birth defect known as microcephaly in which the baby is born with an abnormally small head and brain.

Preventing Blood Exposure

While there have been several cases in Brazil where the Zika virus has been passed through a blood transfusion, the risk is considered low. While research is ongoing, current evidence suggests that the virus is less able to persist in blood and will likely clear within 13 days.

Newly implemented guidelines by the U.S. Food and Drug Administration further reduces the risk by routinely screening blood donations and removing any which tests positive for the Zika virus from the blood supply.

If this doesn't offer you enough assurance, you can make an autologous donation by which you donate blood for yourself prior to a surgery or planned medical procedure. Autologous donations require a doctor's prescription. Contact your provider to find out if you are eligible to make such a donation.

Zika Virus Doctor Discussion Guide

Get our printable guide for your next doctor's appointment to help you ask the right questions.

Download PDF

Email the Guide

Send to yourself or a loved one.

Sign Up

This Doctor Discussion Guide has been sent to {{form.email}}.

There was an error. Please try again.

Vaccine Development

In March 2017, a Phase II human trial was approved to test a genetically engineered vaccine based on the same model used to develop a West Nile virus vaccine. A total of 80 participants were registered for the trial which will be conducted over three years at three sites in the United States.

The investigational vaccine contains genes that, when injected into the arm, provides the body with the information needed to build Zika-like particles. While these particles are not infectious, the immune system will respond to them as if they were and launch an immune defense. The same model has been used successfully in creating vaccines for other viral diseases.

Should the results of the two-stage trial be successful, Phase III testing may begin by as early as 2020. Other vaccine models are in the preliminary stages of investigation.