Chikungunya: Are We on the Way to Finally Having a Vaccine?

A recent trial shows promising results for a chikungunya vaccine, providing a ray of hope against the disease.

Highlights:

Chikungunya is a viral disease spread to humans by mosquito bites infected with the chikungunya virus
A recent study has shown that a new single-shot vaccine could be on the horizon
The vaccine showed an efficacy of 99%, however, studies in endemic areas are required

The chikungunya virus is transmitted to humans by the bite of an infected mosquito. Fever and joint discomfort are the most typical symptoms of infection. Other signs and symptoms may include a headache, muscle soreness, joint swelling, or a rash.

There have been outbreaks in Africa, the Americas, Asia, Europe, and the Caribbean, Indian, and Pacific Oceans. Infected tourists pose a risk of spreading the illness to uninfected places. Currently, there is no treatment or vaccine for chikungunya. A recent study gives hope for a potential vaccine.

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‘A new trial shows that a single-shot vaccine against the chikungunya virus is 99% effective.’

VLA1553: A Promising Vaccine for Chikungunya

A vaccine candidate developed by the French-Austrian pharmaceutical company Valneva against chikungunya showed promising results in a big new trial, according to a recent report ().

While the findings were welcomed as promising in the fight against chikungunya, the experiment was conducted on patients in the United States, where the illness is extremely rare, and experts said additional research was required.

According to Valneva, its vaccine candidate, VLA1553, is the first to be assessed by health authorities after submitting for clearance in the United States and Canada.

The new randomized, placebo-controlled phase three experiment sought to determine how frequently the live-attenuated vaccine, which employs a weakened version of the virus, elicited an immune response.

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The Chikungunya Vaccine is 99% Effective

The study, which was published in the journal The Lancet, found that 263 of a subgroup of 266 recipients of the vaccine - or 99% - developed antibodies that could destroy the chikungunya virus.

The single-shot vaccination was declared "generally safe" with adverse effects comparable to previous vaccines in a larger experiment involving 4,100 healthy adults.

In the study, just two people experienced severe adverse effects related to the vaccine, and both made a full recovery.

The study's principal author and manager of clinical strategy at Valneva, Martina Schneider, termed the findings "promising."

"This could be the first chikungunya vaccine available for people living in endemic regions, as well as for travelers to endemic areas or areas at risk for an upcoming outbreak," she said in a statement.

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Vaccine is Esssential as Chikungunya Could be the Next Pandemic

Public health experts are concerned that chikungunya could become a future pandemic threat if climate change pushes the mosquitos that spread it into new areas.

The latest study, according to Kathryn Stephenson, an infectious disease specialist at the Beth Israel Deaconess Medical Center in the United States, is "good news for chikungunya virus pandemic preparedness."

“But the vaccine might be less effective in areas with a built-up immunity to chikungunya, which can happen with such live-attenuated shots”, she added.

Since chikungunya was first identified in Tanzania in 1952, it has been recorded in more than 110 countries, according to the World Health Organization ().

The US Food and Drug Administration may decide whether to approve the vaccine around the end of August, according to Valneva.

The vaccine is also being tested on adolescents in areas of Brazil where the virus is endemic.

Stephenson said the Brazilian trial and further research conducted during actual chikungunya outbreaks were "crucial" to establishing the vaccine's effectiveness.

A chikungunya vaccine candidate produced by Bavarian Nordic in Denmark is also in phase three trials.

References:

Safety and immunogenicity of a single-shot live-attenuated chikungunya vaccine: a double-blind, multicentre, randomised, placebo-controlled, phase 3 trial - (https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(23)00641-4/fulltext)
Chikungunya - (https://www.who.int/news-room/fact-sheets/detail/chikungunya)

Source-Medindia

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