Dengue fever is an illness transmitted by mosquito bites. Affecting around 390 million people per year, if left untreated, its mortality rate is 20%. Although vaccines have been developed to tackle the condition, so far, they have been limited in efficacy. This may change however thanks to promising preliminary results from a new vaccine developed by Japanese pharmaceutical firm, Takeda.
The first vaccine for the disease, known as Dengvaxia, was approved in 2016. Although effective in some cases, it has limited utility due to its reputation for increasing the risk of serious illness among people with no previous exposure to Dengue fever, and is thus only used on those who have already been infected with the virus.
Unlike Dengvaxia, the new vaccine developed by Takeda seems to be effective for both those who have previously had Dengue Fever and those with no previous exposure.
Based on a weakened form of the live virus, researchers compared the new drug to a placebo in a trial of over 20,000 children aged between 4 and 16 in 26 locations around Asia and Latin America. With each child receiving two doses of the vaccine three months apart, so far results from a one-year follow up after the second dose show the vaccine to be 80.2% effective (Steenhuysen: 2019).
Out of the four versions of the Dengue virus in circulation, the new vaccine appears to offer good protection against one type, and partial protection against two others. Although exciting news for regions where this condition is widespread and researchers alike however, a three-year follow-up is still necessary to confirm its protective results are stable (Wong: 2019).
According to Duane Gubler at Duke-NUS Medical, Singapore, a patent holder of the new vaccine, “If these results hold during long-term follow-up and if the vaccine shows a significant reduction in severe disease, this vaccine, if used properly, could have a major impact on our ability to prevent and control the pandemic of dengue currently ravaging the world (ibid).”,
Rajeev Venkayya, president of Takeda added, “While more data is needed to fully understand the safety and efficacy profile of TAK-003, these findings strongly suggest that it could help address the massive global burden of dengue in all populations. We look forward to sharing more data in the coming weeks, and engaging health authorities and the scientific, public health and medical communities on these findings, priorities for future evidence generation, and ways we can work together to maximise the reach and impact of this vaccine upon licensure (BL: 2019).”
Steenhuysen, Julie: Reuters
Wong, Sam: New Scientist