A fever, followed by joint pain for years: this is the reality for many people affected by chikungunya, a disease transmitted by mosquitoes. While the initial symptoms are often intense, it is especially the long-term complications that capture the attention of healthcare professionals.
A notable proportion of patients indeed suffer from persistent pain, sometimes lasting months or even years, similar to certain forms of arthritis. In this context, finding an effective means of prevention is a priority.
Researchers from Griffith University in Australia have made a significant advance in this direction. Their work is based on an innovative approach to developing a vaccine against this virus. Instead of using attenuated or inactivated viruses, the team opted to create synthetic particles that perfectly mimic the outside of the chikungunya virus. These particles serve as decoys to train the immune system without causing the disease.
The tiger mosquito Aedes albopictus is recognizable by the white bands that stripe its legs. It is notably the vector for dengue and chikungunya viruses as well as the Zika virus.
Wikimedia Commons / Centers for Disease Control and Prevention To manufacture these decoys, the scientists used modified E. coli bacteria as tiny biological factories. These bacteria produce biopolymer particles carrying chikungunya-specific antigens on their surface, particularly the E2 and E1 proteins. Professor Bernd Rehm specifies that these particles, without adjuvants, so closely resemble the real virus that they trigger a robust immune reaction. The body's defense system identifies them and thus prepares to fight a future real infection.
This method has the advantage of being safe, as it does not require the use of the live virus, attenuated virus, or even viral fragments. The synthetic particles are simply absorbed by key immune cells, which then learn to recognize the true enemy. Preclinical trials indicated that this approach induced promising immune protection, paving the way for human testing. The results of this study were published in the journal
Biomaterials.
The progression of the disease itself helps to grasp the importance of such a discovery. After a bite from an infected mosquito, the virus multiplies in the blood and heads primarily to the joints, muscles, and connective tissues. It then causes significant inflammation and direct damage. Even after the virus is cleared, the immune system may continue to attack joint tissues, leading to chronic pain for up to 60% of patients.
The research team now plans to move to the clinical development of the vaccine candidate. The next steps will involve conducting trials to assess the safety of the formulation in human volunteers, before testing its real effectiveness in preventing infection. This strategy could provide a valuable tool for limiting outbreaks, particularly in tropical and subtropical regions where the vector mosquitoes are very prevalent.