Why are US health officials advising against chikungunya vaccine for the elderly?

The Centers for Disease Control (CDC) issued an advisory last week urging the American travellers to avoid taking chikungunya vaccine, Valneva's 'Ixchiq'. In the wake of the chikungunya outbreaks in several regions including the islands of the Indian Ocean, health officials had urged the elderly to take the vaccine shots against the disease.

 

France's Departments of La Reunion and Mayotte have reported chikungunya outbreaks. La Reunion has reported over 47,000 cases and 12 associated deaths as on May 4 this year. 

 

According to the World Health Organisation (WHO), cases are expected to further rise in the islands of the Indian Ocean. 

 

With the chikungunya cases rising, CDC issued a travel advisory saying pregnant women to reconsider their travel plans to the affected areas. "Mothers infected around the time of delivery can pass the virus to their baby before or during delivery," it said. 

 

The Chikungunya vaccine was recommended by the government especially for those frequently travelling.

 

However, after adverse events were reported following the vaccine administration globally, the CDC has issued another advisory, advising the elderly to refrain from taking the vaccine. 

 

Those who received the vaccination, especially the elderly with comorbidities, were affected with heart or brain-related issues within a week of vaccination. 

 

What is chikungunya?

 

Chikungunya is a mosquito-borne viral disease caused by the chikungunya virus. Symptoms of the disease include fever and joint pain. The risk of a person spreading the virus is highest during the first week of illness.  

 

The European Union's health regulator is currently reviewing Valneva's chikungunya vaccine after reports of serious adverse events, including two deaths globally. 

 

The European Medicines Agency's safety committee has temporarily suspended the use of the vaccine- Ixchiq, in adults aged 65 years and above. 

 

Ixchiq is the first preventive vaccine against the chikungunya virus authorised in Europe and the US. 

 

Among the adverse events included the death of adults aged 62 and 89 years. However, the exact link between the vaccine and the death is being determined by the health officials. 

 

The French government had suspended the use of the vaccine pending investigation after adverse events were reported as well. 

 

Meanwhile, the US advisors have recommended the second chikungunya vaccine, Bavarian Nordic's Vimkunya to those above 12 years of age. 

Health