If you have suffered from Chikungunya once, you are immune for lifetime, to be suffered from it again. As per the microbiology department of AIMS, Chikungunya disease is caused by one serotype and the chances of repeated infection caused by the same serotype is minimum. Whereas; Dengue is caused by 4 closely related serotypes of the virus. After recovery, Dengue patient develops life long immunity from one serotype of virus, from which he got sick. Cross immunity to other serotypes is partial and temporary after recovery. Second time infection from other serotypes makes the patient’s condition worse and often turns fatal. This is the biggest challenge in inventing the vaccine for Dengue. Dengvaxia, the first Dengue vaccine is approved in some endemic countries (not India) for use in ages 9-45 years. However, this vaccine should not be given to persons who have never been infected with Dengue, even once in life. As, Dengue vaccine has attenuated or weak virus, which acts very much, like a natural infection, without making the recipient sick. But, if the vaccinated person is infected with virus again in life, immune system treats it as a second infection that has much severe consequences. This drawback prohibits the use of vaccine in children below 9 years, as they may be the ones who are most likely to be untouched by the prior Dengue infection.
Aedes aegypti mosquito is responsible for the spread of viral infections like Dengue, Chikungunya and Zika. The vector control strategies may work best right now. The right vaccine, best suited to prevent these viral infections for all the age groups might take years of research and trials.
Chikungunya victims might heave a sigh of relief with the news confirming that, they will never suffer from this highly painful disease again. The fatalities observed in case of Chikungunya cannot be solely related to it but the concurrent underlying other medical conditions like sepsis, kidney injury and pneumonia in the patient.
Source: AIMS microbiology