Effectiveness of Live-Attenuated Chikungunya Vaccine, VAL1553
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Reviewed by Dat Tien Nguyen, B.A, ScM.
Translated by Nhi Phuong Quynh Le, B.A |
Posted on July 14th, 2025
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Chikungunya is a viral infection by the CHKV virus which is associated with arthralgia and myalgia. The virus is transmitted by the Aedes aegypti and Aedes albopictus mosquitoes, which is commonly found across Asia. With funding from the pharmaceutical company Valneva Austria and the European Union, a study was conducted to assess the effectiveness of a vaccine to prevent chikungunya infection.
The phase 3 clinical study was conducted in the United States with 363 participants. The cohort was randomly assigned to receive a single intramuscular injection with either a placebo or the VLA1553. The live-attenuated vaccine contains one thousand infectious doses per 0.5 mL of a variant of the CHKV virus that had a portion of the nsP3 gene deleted. As a result, the vaccine CHKV strain can replicate enough to induce an immune response, but not effective enough to cause disease.
Immunogenicity analysis 2 years after administration found that the VAL1553 vaccine was effective at achieving the substantial level of neutralizing antibodies. Additionally, the vaccine did not result in significant adverse events. The researchers noted that their study had some limitations with a small number of participants above the age of 65 years old, the lack of diversity in the study population, and the exclusion of immunocompromised participants and pregnant women.
The phase 3 clinical study was conducted in the United States with 363 participants. The cohort was randomly assigned to receive a single intramuscular injection with either a placebo or the VLA1553. The live-attenuated vaccine contains one thousand infectious doses per 0.5 mL of a variant of the CHKV virus that had a portion of the nsP3 gene deleted. As a result, the vaccine CHKV strain can replicate enough to induce an immune response, but not effective enough to cause disease.
Immunogenicity analysis 2 years after administration found that the VAL1553 vaccine was effective at achieving the substantial level of neutralizing antibodies. Additionally, the vaccine did not result in significant adverse events. The researchers noted that their study had some limitations with a small number of participants above the age of 65 years old, the lack of diversity in the study population, and the exclusion of immunocompromised participants and pregnant women.