India Approves QDENGA Vaccine To Fight Dengue

India has approved a new vaccine, QDENGA, to fight dengue, a disease that has seen a significant rise in reported infections over the past two decades. The vaccine, developed by Takeda Biopharmaceuticals India, has been granted market authorisation by the Drug Controller General for use in individuals between 4 and 60 years of age.

The QDENGA vaccine is designed to provide protection against all four types of dengue viruses through a two-shot regimen, with a claimed efficacy of 80.2% on infection and 90.4% on hospitalisation. This is a significant development, given the high burden of dengue in India, with reported cases rising from 44,585 in 2020 to 2.33 lakh in 2024.

The government has been working to prevent and diagnose dengue through a network of 869 sentinel surveillance hospitals and 27 apex referral laboratories, providing free diagnosis and treatment. However, the availability of an effective vaccine is expected to be a game changer for millions of people who encounter health system bottlenecks.

The QDENGA vaccine uses a combination of antibody defences against the four types of dengue viruses through live attenuated, or weakened, viruses, regardless of previous infection. This comprehensive protection is aimed at reducing the significant disease burden in India.

However, it is essential to closely watch the progress of vaccination and the phenomenon of adverse events that sometimes follows. The experience of Brazil, where adverse events after dengue vaccination using a similar tetravalent vaccine took a deadly turn due to a phenomenon known as Antibody Dependent Enhancement (ADE), is instructive.

ADE occurs when antibody levels are insufficient, and the infection worsens, requiring vigilance and treatment to prevent fatal consequences. The makers of QDENGA will need to work closely with state public health authorities to scale up the vaccination effort and institute a system to report side effects, adverse events, and provide free medical care to those who may be at risk of ADE.

Other dengue vaccine candidates, including DengiAll, are also in clinical trials, with potential for approval. Diligent vigilance and transparency in publishing clinical trial data for all these candidates will raise confidence that the vaccines are safe and well tolerated.

The approval of QDENGA marks a public health milestone in India's fight against dengue. With the vaccine's efficacy and safety closely monitored, it is expected to make a significant impact in reducing the disease burden in the country.

The government's approach to dengue has been one of prevention and free diagnosis, but the availability of an effective vaccine is expected to change the landscape of dengue prevention and treatment in India. As the vaccination effort scales up, it is essential to ensure that supportive policies are in place to provide treatment to those who may develop complications.

In conclusion, the approval of QDENGA is a significant step forward in India's fight against dengue. With its efficacy and safety closely monitored, the vaccine is expected to make a significant impact in reducing the disease burden in the country.