A vaccine for the chikungunya virus is entering human trials, despite the vaccine only being in phase I trials, the media are once again hailing it as a predestined success. The vaccine is being developed by Hyderabad-based Bharat Biotech. Currently there are no commercial chikungunya vaccines available; Bharat Biotech hopes its vaccine will become the first offering hope that the disease will become preventable in the coming years.
A sceptical approach to the vaccine is warranted. The Business Standard suggests that Bharat Biotech have been announcing a number of vaccines since 2016 in order to increase their publicity in the wake of calls by their shareholders of a major selloff of stocks. Early announcements are a dangerous practice, and inviting of disappointing news down the line. As noted in an article on Hyderus, the rate of failure during clinical trials is extremely high.
Chinkungunya is a clear threat in India due to its transmission via a mosquito vector. This makes the disease difficult to eradicate from a population due to high recurrence rates. The disease is characterised by acute fever and joint pain, potentially lasting for months. Though the disease is not often fatal, it can contribute to the deaths of the elderly, or those who are already in a weakened state.
The vaccine has so far shown promising results in animal models (mice, rats and rabbits) claims Bharat Biotech during a press release. The testing has been extensive and applied to several strains of chikungunya. Mentioned during the press release were the Asian virus isolated in 1963 as well as the East Central South African viruses responsible for outbreaks in India since 2006. A patent was filed for the vaccine in 2007.
The vaccine is currently in phase I human trials, the first step of a three stage process designed to test the safety and efficacy of a medication. Phase I involves a small scale trial, in this case conducted on 60 people. The intention of this part of the trial is to assess safety in human patients. Of the 60 people, either the vaccine or a placebo will be administered and the results compared.
The vaccine uses a dead strain of the chikungunya virus. This means that the virus present in the vaccine should not have the capacity to replicate itself, though introducing it would expose the vaccines recipient to the virus’s genetic material. This allows for the body to develop antibodies specific to the virus without any risk of harm. In the future, the immune response to a potential infection by a live virus is far more rapid and efficient, giving an increased chance of fighting off the infection.
Should the vaccine pass the safety tests of phase I trials, it will pass into the efficacy and dosage analysis stages. This will analyse at what dose the vaccine is most effective without causing any major side effects, as well as assess the protection rate against the disease in those who received the vaccination.
Parallel to Bharat Biotech’s vaccine, another chikungunya vaccine from Themis Bioscience of Vienna, Austria, is also undergoing human trials. This vaccine takes a different route and uses a modified measles virus expressing chikungunya proteins to stimulate immune response.
Both vaccines represent a shred of hope to those under constant threat of infection from chikungunya, in India as well as internationally. Bharat Biotech’s vaccine also represents a domestic research effort within India against a disease that has had yearly outbreaks following rainy periods when mosquito populations soar. However, due to the high rates of failure in pharmaceutical research, a cautious approach is advised, success in this industry is never a guarantee.