The FDA’s information on the vaccine says that ‘vaccination with IXCHIQ may cause severe or prolonged chikungunya-like adverse reactions.’
The U.S. Centers for Disease Control and Prevention said it is investigating the hospitalizations of five people who recently received a vaccine for the chikungunya virus, which is transmitted via mosquitoes.
In a notice on Tuesday, the CDC said that the five hospitalizations occurred in people aged 65 and older and that they suffered cardiac or neurologic problems after receiving a vaccine known as IXCHIQ.
“This topic will be discussed at an upcoming meeting of the Advisory Committee on Immunization Practices (ACIP). Healthcare providers should discuss the benefits and risks of vaccination with individual travelers based on their age, destination, trip duration, and planned activities,” the agency said.
Chikungunya is a rare viral disease spread by infected mosquitoes that can cause joint pain and fever, circulating in subtropical and tropical areas. There have been outbreaks of the disease in the United States, namely in the years 2014, 2015, and 2016, but local cases have not been reported since 2019, the CDC says.
According to the CDC’s website, the IXCHIQ vaccine contains a live but weakened version of the chikungunya virus. The shot, made by Valneva, was approved by the U.S. Food and Drug Administration (FDA) in November 2023, described as “the first chikungunya vaccine” and for adults who are “at increased risk of exposure to chikungunya virus.”
The FDA’s information on the vaccine says that “vaccination with IXCHIQ may cause severe or prolonged chikungunya-like adverse reactions” and it lists contraindications such as an immune-compromising condition or an allergic reaction.
“Common adverse reactions following vaccination that occurred in [greater than 10 percent] of vaccinated persons in clinical trials included tenderness, headache, fatigue, myalgia, arthralgia, fever, and nausea,” the CDC said.
The chikungunya vaccine would have been discussed in an ACIP meeting scheduled for Feb. 26, according to a readout of proposed topics for discussion during that meeting. The meeting was postponed by the CDC earlier this week.
