Researchers at the Medical University of Vienna create a promising vaccine for Chikungunya, a virus with currently no preventative treatment. The virus is becoming a global threat after spreading to the United States and Europe, causing high fever and debilitating arthritis in those infected.
The word Chikungunya in the Kimakonde language (mid-east African region) means, “that which bends-up.” The infection can cause severe joint pains, which forces the joints to bend in order to decrease the discomfort. The virus is transmitted to humans through mosquito bites infected with CHIKV.
In the study, the researchers developed a recombinant measles virus-based vaccine with CHIKV features to induce antibodies’ production against CHIKV. Forty-two participants were divided across four groups, received either a control measles vaccine or the candidate Chikungunya vaccine in either a low, medium or high dosage, and were tested 28 and 90 days later for immunogenicity by measuring the anti-Chikungunya antibodies present in the blood.
Functional antibodies against Chikungunya were found in all groups that received the candidate vaccine, but only the high-dose group had steady levels of antibodies after three months. The medium and low dosages, on the other hand, required booster shots of vaccine for antibody levels to remain elevated.
The total number of adverse side effects due to the candidate vaccine increased in higher dosage groups. Five side effects were related to the candidate vaccine, including severe headaches, swelling or severe pain at the site of injection, hardening of the soft tissue near the site of injection, and high fever. These more serious side effects were mostly present in the high dosage group, and may have been related to either the high inoculation volume (1mL) or the content of the salt buffer used to deliver the vaccine.
Before the candidate vaccine, only two other Chikungunya vaccines have made it to human trials. An advantage of this candidate vaccine is that it is based on the measles vaccine, which is considered one of the safest and most efficient human vaccines. Since the vaccine does not contain live Chikungunya virus but certain attributes of the same, it allows the body’s immune system to create antibodies for Chikungunya, while completely removing the risk of Chikungunya-like symptoms in patients.
Based on the results of the first trials, researchers believe that the medium dose has the best ratio of immunogenicity and tolerability, still requiring a booster shot to achieve full immunity.
According to the authors, further clinical tests would be required to check the efficacy of the vaccine in different age, racial and ethnic groups, since the preliminary results were obtained in a volunteer Caucasian population. Nevertheless, as the authors state in the publication, “This vaccine is the first promising measles virus-based candidate vaccine for the prevention of Chikungunya fever in human beings.”
Written by Aaron Oraham
Ramsauer, K., Schwameis, M., Firbas, C., Müllner, M., Putnak, R., Thomas, S., . . . Tangy, F. (2015). Immunogenicity, safety, and tolerability of a recombinant measles-virus-based chikungunya vaccine: A randomised, double-blind, placebo-controlled, active-comparator, first-in-man trial. The Lancet Infectious Diseases, 15(5), 519-527.
Chikungunya. (n.d.). Retrieved November 19, 2015, from http://www.dovemed.com/chikungunya/