Scientists at the Indian Institute of Technology (IIT) Roorkee have identified a promising new approach to treating Chikungunya, a debilitating mosquito-borne viral disease that causes fever, joint pain, and rash. Their research demonstrates that efavirenz, a non-nucleoside inhibitor commonly used in HIV/AIDS treatment, can effectively inhibit Chikungunya virus replication both in laboratory settings and animal models.
The study, supported by the Indian Council of Medical Research (ICMR) and published in the journal ACS Infectious Diseases, represents a significant step forward in addressing a disease that currently has no approved antiviral treatment.
Significant Viral Inhibition in Laboratory Studies
The research team, led by Prof. Shailly Tomar from IIT Roorkee's Department of Biosciences and Bioengineering, found that efavirenz inhibited Chikungunya virus replication by nearly 99% even at low micromolar concentrations in various cell lines.
"Our findings suggest that efavirenz can interfere with the virus early in its replication process," explained Dr. Sanket Nehul, the first author of the study. "The drug acts during the early phase of Chikungunya replication after virus entry."
The researchers conducted comprehensive testing using both Vero cells and human hepatic cell lines, the latter chosen because Chikungunya virus naturally targets hepatocytes during infection. Treatment with efavirenz demonstrated prominent inhibition of viral replication up to six-eight hours post-infection.
Promising Results in Mouse Models
When tested in Chikungunya-infected mice, efavirenz treatment significantly reduced viral load, which in turn decreased viral propagation in the mice footpads. Interestingly, while the treatment led to increased swelling in the limbs—attributed to the pro-inflammatory action of efavirenz—the viral load reduction remained significant.
"Viral replication was also inhibited when Chikungunya-infected mice were treated with efavirenz," noted Prof. Tomar. "It was also observed that efavirenz is able to inhibit the replication of Sindbis virus, which is evolutionarily closely related to the Chikungunya virus."
Addressing a Growing Public Health Concern
Chikungunya has been a recurring public health challenge in India since its reappearance in 2006 after a 20-30 year gap. According to data from the National Center for Vector-Borne Disease Control, cases have surged in recent years, with over 70,000 confirmed cases reported in 2024 alone.
"At present, people infected with Chikungunya rely on symptom management as there is no specific antiviral treatment," said Prof. Tomar. "Our study provides initial scientific evidence that efavirenz might be a potential antiviral drug for Chikungunya treatment."
Advantages of Drug Repurposing
The potential repurposing of efavirenz for Chikungunya treatment offers several advantages. As an already approved medication with established safety profiles and pharmacokinetic properties, efavirenz could significantly reduce the time and cost typically required for developing new antiviral drugs.
The paper cites a case study of a 43-year-old HIV-positive person infected with Chikungunya virus who showed improved condition while being treated with antiretroviral drugs including efavirenz. While improvement cannot be solely attributed to efavirenz, as the patient was treated with multiple drugs, the observation aligns with the anti-Chikungunya activity observed in the current study.
Path Forward: Clinical Trials Needed
Prof. Kamal Kishore Pant, Director of IIT Roorkee, emphasized the institution's commitment to addressing public health challenges: "This study is a step toward finding possible solutions for mosquito-borne viral infections."
While the findings are promising, the researchers caution that further clinical trials will be necessary to determine whether efavirenz can be a safe and effective treatment for Chikungunya in humans.
"Based on good pharmacokinetics properties, previous successful applications of efavirenz to treat HIV infection, and the demonstrated anti-Chikungunya activity in this study, efavirenz shows high potential for repurposing against human Chikungunya infections," concluded Prof. Tomar. "Further clinical human trials can be conducted in this direction."
