Chikungunya cases in the European continent due to autochthonous transmission [ver]
Development of vaccines against the chikungunya virus [ver]
More information on this website, bibliographical references and recommended links [ver]
In a nutshell
Vector-borne diseases account for more than 17% of all infectious diseases and each year cause more than 700,000 deaths worldwide. They can be caused by parasites, bacteria or viruses.
The chikungunya virus is transmitted by the bite of the Aedes mosquito and is present in vast regions of the American, African and Asian continents. No autochthonous case has been registered on the European continent since 2017 (cases in France and Italy between 2007 and 2017).
In the first five months of 2023, almost half a million cases have been reported (most of them in Brazil, Paraguay, Argentina, Bolivia and Thailand) and almost 300 deaths (most in Paraguay).
There are no specific treatments or vaccines for this disease. The treatment used is symptomatic and supportive, and prevention rests on the control of the vector mosquito and the avoidance of its bites.
Data from phase 3 studies with two vaccine candidates have recently become known: an inactivated one for people aged 65 or over and an attenuated one in adults from 18 years of age.
The live vaccine tested (VLA1553-301, from Valneva) shows promising immunogenicity, efficacy and safety data. It could play a relevant role in the control of outbreaks (a single dose, early serological response).
However, more research is needed with other products to overcome the limitations of live vaccines.
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Vector-borne diseases
The transmission of diseases through vectors, known as vector-borne diseases (VBD), refers to human diseases caused by bacteria, parasites, or viruses that are transmitted by living organisms. These vectors transmit infections from infected animals to humans or other animals.
VBDs account for more than 17% of all infectious diseases and cause over 700,000 deaths worldwide each year. They can be caused by parasites, bacteria, or viruses. Some examples of vector-borne diseases include:
Malaria or malaria, which is a parasitic infection transmitted by mosquitoes of the Anopheles genus. It is estimated to cause 219 million cases and over 400,000 deaths annually, with most deaths occurring in children under 5 years of age.
Dengue, the most common viral infection transmitted by Aedes mosquitoes. Over 3.9 billion people in more than 129 countries are at risk of contracting dengue, with an estimated 96 million symptomatic cases and 40,000 deaths reported each year.
Other vector-borne viral diseases include chikungunya, Zika, yellow fever, West Nile fever, and Japanese encephalitis, all transmitted by mosquitoes, as well as tick-borne encephalitis.
Other vector-borne diseases include schistosomiasis, human African trypanosomiasis, leishmaniasis, Chagas disease, and onchocerciasis.
These diseases primarily affect low development index countries in tropical and subtropical regions.
Source: WorldHealth Organization (WHO), March 2020.
Vector-borne diseases
Vector
Diseases
Virus
Bacteria
Parasite
Mosquito
Anopheles
Chikungunya, dengue, Rift Valley fever, yellow fever and Zika
From 2007 to January 2023, the ECDC has recorded the following cases of autochthonous chikungunya in Europe:
In 2007, Italy reported around 330 cases, with the index case originating from India.
In 2010, France reported 2 cases, with the index case originating from India.
In 2014, France reported 12 cases, with the index case originating from Cameroon.
In 2017, France reported 17 cases, with the index case originating from Central Africa.
In 2017, Italy reported 270 confirmed and 219 probable cases, with the index case originating from India and Pakistan.
No cases have been registered since 2017.
Progress in Chikungunya Vaccines
Recent advancements have been made in the development of vaccines against the chikungunya virus:
Bavarian Nordic has reported positive results from a Phase 3 study of their vaccine in adults aged 65 and older.
Valneva has published the results of a Phase 3 study with their vaccine, showing promising immunogenicity and safety profiles.
Valneva’s vaccine is based on an attenuated virus isolated from an outbreak in Réunion in 2006. The vaccine has shown good results in preclinical studies.
The studies conducted in the US have limitations in terms of generalizability to endemic regions. However, the vaccines show potential in controlling outbreaks and protecting against chikungunya.
In a study conducted in the US, 99% of vaccinated participants developed a response after a single dose. Seroprotection persisted in over 96% of participants after six months.
The vaccine demonstrated a good safety profile with mild adverse effects.
This vaccine, although effective, has limitations such as restricted use in certain populations and storage requirements. Additional vaccines are needed to cater to all age groups and conditions.
With the impact of climate change on vector habitats, the need for effective prevention tools will continue to grow in the future.
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For more information:
CAV-AEP: Other news about the chikungunya virus and its vaccines.
CAV-AEP, October 23, 2017: Autochthonous chikungunya outbreaks in Europe.
CAV-AEP, August 3, 2018: The return of the tiger mosquito and the risk of chikungunya and dengue fever in Europe.
CAV-AEP, June 22, 2018: Mosquito saliva vaccine: the universal solution against arboviruses?
References and recommended links:
Bartholomeeusen K. et al. Chikungunya fever. Nat Rev Dis Primers. 2023;9:17.
Bavarian Nordic, June 20, 2023. Bavarian Nordic Reports Data from a Phase 3 Clinical Trial of its VLP-Based Chikungunya Virus Vaccine in Adults ≥65 Years of Age.
CDC. Chikungunya virus.
ECDC, Factsheet. Chikungunya virus disease.
ECDC, Latest outputs. Chikungunya virus disease.
ECDC, June 19, 2023. Chikungunya worldwide overview.
ECDC, January 30, 2023. Autochthonous transmission of chikungunya virus in mainland EU/EEA, 2007–present.
Chikungunya: A Growing Threat to the Americas
The World Health Organization (WHO) has identified Chikungunya as a significant concern, with outbreaks occurring worldwide. According to a report published by the WHO on December 8, 2022, Chikungunya is a viral disease transmitted by mosquitoes. It causes fever, joint pain, and other debilitating symptoms. The disease has been spreading rapidly, posing a threat to the population of the Americas.
Vector-Borne Diseases: A Widespread Issue
In a separate report released on March 20, 2020, the WHO highlighted the alarming rise of vector-borne diseases. These diseases, including Chikungunya, are transmitted by insects such as mosquitoes and ticks. The report emphasized the need for increased efforts to control and prevent these diseases to protect public health.
10 Vector-Borne Diseases Putting the Americas at Risk
A joint publication by the Pan American Health Organization (PAHO) and the WHO identified ten vector-borne diseases that pose a significant risk to the population of the Americas. Chikungunya was listed as one of the diseases with the potential to cause widespread harm. The report called for urgent action to address the growing threat and protect vulnerable communities.
Promising Results from Chikungunya Vaccine Trial
A recent study published in The Lancet on June 12, 2023, showcased the safety and effectiveness of a single-shot live-attenuated Chikungunya vaccine. The double-blind, multicenter, randomized, placebo-controlled phase 3 trial demonstrated positive outcomes, providing hope for the prevention and control of Chikungunya. Experts have hailed this development as a potential game-changer in the fight against the disease.
A New Era in Chikungunya Prevention
Another article published in The Lancet on June 12, 2023, discussed the live-attenuated Chikungunya vaccine as a significant advancement in disease prevention. The study highlighted the potential of this vaccine to revolutionize the approach to Chikungunya control and reduce the burden on healthcare systems.
Valneva, a leading pharmaceutical company, announced on June 13, 2023, the publication of its Chikungunya vaccine candidate’s phase 3 data in The Lancet. The results demonstrated the vaccine’s efficacy and safety, further fueling optimism in the fight against Chikungunya.
Chikungunya: A Global Threat with Historical Roots
A study published in the Journal of Infectious Diseases in 2016 explored the history and spread of Chikungunya. The research traced the origins of the disease in Africa and Asia and its subsequent emergence in new regions, including the Americas, in 2013-2014. Understanding the historical context of Chikungunya is crucial in developing effective strategies to combat its spread.
