The Indian Council of Medical Research (ICMR) has  revealed that the current formalin inactivated vaccine against Kyasanur Forest Disease (KFD) has no approval from the World Health Organisation (WHO) and has been found to be “ineffective” against the deadly disease which is not only on the rise but also spreading in new areas in the country.

It has now floated the expression of interest (EoI) asking pharma firms and research organizations to come forward to develop new vaccines to wipe out the deadly disease that inflicts mainly forest and agricultural workers.

The KFD is a highly infectious viral illness transmitted by infected ticks through contact with monkeys and other wild animals. While till date there is no definite treatment available for KFD, the current vaccine potency too seems to be failing as has also been noted by the ICMR.

In a latest circular inviting expression of interest (EoI), the research body said, “… recent data show recurrence of KFD cases even in the vaccinated subjects, which may probably be due to the suboptimal efficacy of the current vaccine or vaccination protocol.

Additionally, the vaccine associated side effects, such as pain, and administration of booster doses for five years are also believed to be some of the potential discouraging factors that might affect the vaccine acceptability.”

To overcome this problem, the ICMR has taken “initiative for development of a new vaccine candidate which is intended to have higher efficacy and safety of the recipients. ICMR NIV Pune has isolated and characterized KFDV isolates from the recent outbreaks of KFDV held in Karnataka State...”

 It further pointed out that KFDV outbreaks are very common in recent years highlighting the need for more potent countermeasures including more effective vaccines.

“The seed virus used for the current KFD vaccine P9605 was isolated in 1965 and has undergone several passages in mice. The current vaccine is formalin inactivated and does not have WHO approval. Also the current vaccine that was developed based on the strain isolated in early 1970s and not seem effective against the current circulating strain of KFD. There are reports of 2.24% diversity in the currently circulating strains of KFD virus in contrast to the strain used for vaccine preparation which was isolated in 1957. 

Therefore, it may be appropriate to develop a new and future ready KFD vaccine candidate using new isolates and advanced technologies, said the ICMR.

Infact, a study “A live-attenuated viral vector vaccine protects mice against lethal challenge with Kyasanur Forest disease virus,” by scientists from Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA has warned that recent expansion of the KFDV endemic region with increasing KFD case numbers are of alarming public health concern and call out for urgently needed countermeasures including more efficient second-generation vaccines. The  study is published in journal Nature in 2021.