Mosquitoes Carrying West Nile Virus Are Being Found in the U.S. — Is There a Vaccine Yet?

You may have heard the phrase West Nile virus before, but have been unsure about what the disease entails. According to the U.S. Centers for Disease Control and Prevention (CDC), the West Nile virus is a disease that is mainly spread by mosquitoes that have been infected with the illness.

Symptoms and outcomes of the virus can vary depending on severity and pre-existing conditions, which is the reason healthcare providers advise people to avoid contact with potentially infected mosquitoes.

In the most severe cases of West Nile virus, death can occur.

Is there a vaccine for West Nile virus? And if so, who should be heading to the doctor to request a shot? Here's everything we know about the illness, including some symptoms that you should be on the lookout for.

According to the CDC, there are no human vaccines for the West Nile virus. However, one does exist for horses. In fact, the American Association of Equine Practitioners recommends the West Nile vaccine for horses as part of the core list of doses every horse should receive.

That's because the virus is the number one cause of arbovirus encephalitis. According to the association, more than 25,000 cases of this type of encephalitis have been reported since 1999.

Approximately 33 percent of horses that have clinical signs of West Nile virus die, while 40 percent of the horses that survive have ongoing effects from the virus in the months following their illness.

The association reports that there are four vaccinations available in the U.S. that are approved for use against West Nile virus, and it's recommended that horses receive a new vaccine each year before mosquito season kicks off.

Exactly when the timing of that dose will come depends on where the horses live, since different regions experience different degrees of mosquito swarms depending on the environmental conditions in the area.

Since there aren't any vaccines, parents and caregivers may be especially concerned about what to look out for when it comes to their children. The Children's Hospital of Philadelphia (CHOP) says that many children will only experience mild symptoms when infected, which can present within three to 14 days of exposure.

These symptoms typically resemble the flu and last for a few days at a time.

In more extreme cases, children may develop a condition known as West Nile fever as a result of their exposure to the virus. This only happens in approximately 20 percent of cases, and CHOP says these symptoms include:

• Aches
• Rash on the trunk of the body
• Fever
• Headache
• Swollen lymph glands

In more severe cases, which happen in one out of every 150 instances of West Nile fever, CHOP says additional symptoms including stupor, neck stiffness, paralysis, muscle weakness, and coma can occur.

You can read a full list of the symptoms associated with West Nile fever by visiting the CHOP website. Fortunately for parents, it's rare for children to develop this condition, and it's typically only found in adults over the age of 60.