Chikungunya: The Disease & Vaccines

Chikungunya: The Disease & Vaccines

Chikungunya is caused by a virus of the same name. Chikungunya virus is spread through the bite of a mosquito. The disease causes severe joint pain that may last for months or even years. 

Chikungunya occurs in tropical and subtropical regions of Africa, the Americas, Asia, Europe, and islands in the Indian and Pacific Oceans. The U.S. does not recommend chikungunya vaccination for everyone. Rather, the vaccine is recommended for people traveling to areas with current outbreaks or with an elevated risk of an outbreak, as well as laboratory workers who may be exposed to the virus. 

The disease

What is chikungunya and how do you get it?

Chikungunya is a disease caused by infection with chikungunya virus. Chikungunya virus is most often transmitted through the bite of an infected mosquito. Mosquitoes become infected when they bite an infected person or non-human primate. Humans are the main hosts of chikungunya virus during outbreaks. 

Healthcare and laboratory workers have also been infected after handling the blood of someone who is infected. And, although rare, transmission from a pregnant person to their developing fetus is possible, mostly during the second trimester. The baby can also be infected during delivery from an infected mother. The virus has not been found in breast milk. 

Not everyone with chikungunya will experience symptoms. Those who do will typically begin having symptoms 3 to 7 days after being infected. Common symptoms include: 

  • High fever
  • Joint pain that can be severe, debilitating, and affect multiple joints (most commonly those in the hands and feet)
  • Headache
  • Muscle pain
  • Nausea or vomiting
  • Rash 

Rare complications can include:

  • Inflammation of the eye
  • Damage to liver and kidney
  • Swelling of brain or spinal cord
  • Guillain-Barré syndrome (GBS)
  • Neurologic dysfunctions 

Newborns, people more than 65 years of age and those with underlying health conditions are at greater risk for severe disease. Most people recover within 7 to 10 days. However, joint pain and fatigue can be severe and may last for months or even years. People do not usually die from chikungunya disease. 

The vaccines

Chikungunya vaccine is a travel vaccine, but it’s not recommended for all travelers. Most travelers can protect themselves by taking steps to avoid mosquito bites, such as using insect repellent that contains DEET, wearing protective clothing, choosing lodging with air conditioning or screens on windows and doors, and using a mosquito net if sleeping outdoors.

People recommended to get a chikungunya vaccine include: 

  • Travelers to regions experiencing outbreaks
  • People traveling for more than 6 months to places with elevated risk of an outbreak
  • Laboratory workers who handle chikungunya virus

If you are not sure if you would be recommended to get a chikungunya vaccine, talk to your healthcare provider or occupational safety team. If you will be traveling, you might consider scheduling an appointment at a travel medicine clinic. (See “Vaccine Considerations for Travelers” webpage.)

Two vaccines are available with slightly different age recommendations:

A live, weakened vaccine is approved for people 18 years of age and older in a single dose. Currently, this version is not recommended for people 60 years of age and older while a series of serious adverse events among elderly vaccine recipients is being investigated. 

  • See the safety communication on the FDA’s website.
  • Check with your healthcare provider to see if the recommendations have changed if you are more than 60 years of age and recommended to get this vaccine.
  • Of note, the VLP version has not had a similar safety concern.

A virus-like particle (VLP) vaccine is approved for people 12 years of age and older as a single dose. 

How are the chikungunya vaccines made?

There are two chikungunya vaccines in the U.S. One is a live, weakened virus vaccine, and one is a virus-like particle (VLP) vaccine. 

Live, weakened vaccine

Scientists weakened chikungunya virus by deleting a gene from the virus that caused it to lose its ability to replicate well in people. The vaccine virus is grown in monkey kidney cells in the lab. When it is given to people, the virus reproduces enough to generate an immune response, but not well enough to make people sick. Because the vaccine contains a live, weakened virus, it is not recommended to be used in people with weakened immune systems or those who are pregnant. 

VLP vaccine

The VLP vaccine is made from structural proteins from the virus. Genes that are the blueprint for the proteins are added to a plasmid (a small circular piece of DNA) and that plasmid is placed into human embryonic kidney cells. As the cells reproduce in the lab, they also make the chikungunya virus proteins. The chikungunya proteins are then purified and used as the vaccine. The vaccine proteins assemble to look like chikungunya virus, but the structure does not contain chikungunya genetic material, so it can’t reproduce or cause illness (see” How Are Vaccines Made?”).

Do the chikungunya vaccines work?

Live, weakened vaccine

Clinical trials showed that 99 in 100 people who received the vaccine developed an immune response against chikungunya virus by four weeks after vaccination. Three years later, 96 of 100 people still had an immune response against the virus. Researchers are still collecting data to determine how long immunity lasts beyond three years. 

VLP vaccine

Clinical trials showed that 98 of 100 people 12 to 64 years of age and 87 of 100 people 65 years of age and older developed an immune response against chikungunya virus by three weeks after vaccination. Eighty-five of 100 people between 12 and 64 years of age and 76 of 100 people 65 years of age and older still had a measurable immune response against chikungunya virus six months after vaccination. Researchers are still collecting data to determine how long immunity lasts beyond six months. 

Do the chikungunya vaccines have side effects?

People who receive the live, weakened vaccine may experience soreness at the injection site, headache, fatigue, myalgia, arthralgia (joint pain), fever and nausea. In some people these side effects can be severe or prolonged (30 days or more). 

After approval, several reports of elderly people requiring hospitalization for cardiac or neurologic events after vaccination were submitted to the Vaccine Adverse Events Reporting System (VAERS). VAERS is a vaccine safety monitoring system that anyone can report safety events following vaccination. 

Many of the patients reported to VAERS had underlying health conditions and recovered within a few weeks. But because of these reports, the FDA and CDC advised people 60 years and older to refrain from receiving the live, weakened vaccine while this issue is further investigated. 

Common side effects of the VLP vaccine include pain at the injection site, fatigue, headache, and muscle aches. Similar concerns related to safety of the VLP vaccine in elderly patients have not been reported as described for the live, weakened vaccine.

Other questions you might have

What if I am traveling with a child too young to get chikungunya vaccine?

The live, weakened vaccine is not recommended for those less than 18 years of age and the VLP vaccine is not recommended for children less than 12 years of age. Both vaccines are currently being studied in younger children. Until an approved vaccine becomes available for children, they should be protected from mosquito bites in other ways, such as: 

  • Using insect repellent that contains DEET (Note: Insect repellent should not be used on children younger than 2 months of age, and only insect repellent with less than 10% DEET should be used in other children. Combination sunscreen and insect repellent products should not be used in children either).
  • Wear loose-fitting, long-sleeved shirts and pants and closed shoes. Mosquitos may still be able to bite through thin clothing.
  • Choose lodging with screens on windows and doors.
  • Use mosquito nets for sleeping if screens are not available. 

If anyone in your party develops symptoms, including fever, headache, muscle and joint pain, or a rash see a healthcare provider immediately and be sure to let them know where you recently traveled. 

Relative risks and benefits

Do the benefits of the chikungunya vaccines outweigh the risks?

Chikungunya is not common in the U.S. No cases of chikungunya acquired in the U.S. or its territories have occurred since 2019. But some U.S. travelers may benefit from vaccination based on their travel itinerary. While chikungunya is not deadly, the disease can be debilitating, including causing long-lasting joint pain. 

People who may be exposed to the virus because they work with it in a laboratory setting may also benefit from vaccination.

For these reasons only a limited number of people in the U.S. are recommended to get this vaccine. 

Disease risks

  • Fever
  • Severe joint pain
  • Headache, muscle pain, nausea and vomiting, rash
  • Joint pain lasting for months or years
  • Rare complications, including inflammation of the eye, damage to liver and kidneys, swelling of brain or spinal cord, Guillain-Barré syndrome (GBS), and neurological symptoms

Vaccine risks

Live weakened vaccine
  • Pain at the injection site, headache, fatigue, nausea, joint pain, fever
  • People 60 years and older are currently recommended against receiving this vaccine while the vaccine is investigated further following a series of cases of hospitalization for cardiac and neurologic symptoms in older recipients with underlying conditions.
VLP vaccine
  • People 12 to 64 years: Injection site pain, fatigue, headache, muscle pain
  • People over 64 years of age: Injection site pain, fatigue, muscle pain 

References

 

Reviewed by Paul A. Offit, MD, on July 24, 2025