Promising Dengue Vaccine Breakthrough In Bangladesh Trials, Could Be One For The Future.

Dengue situation worsens in Bangladesh ( Niamul Rifat - Anadolu Agency )
- Advertisement -

Bangladesh Health Minister Zahid Maleque yesterday said the recently developed dengue vaccine that was successfully tested in Bangladesh is still on trial, will have to go through more tests,  and it will only be used after approval from the World Health Organisation.

Bangladesh continues to struggle with the virus. Bangladesh has reported 390 deaths from dengue so far in September, 2023.

The dengue vaccine, developed by icddr,b and the Larner College of Medicine at the University of Vermont, requires more trials and WHO’s approval for clinical application against the mosquito-borne disease, he told journalists.

A trial of the vaccine was conducted for the first time in Bangladesh.

The work, evaluating the single-dose tetravalent dengue vaccine candidate TV005, demonstrated safety and immune responsiveness in children and adults, said icddr,b sources, adding that the accompanying study was recently published in the Lancet Infectious Diseases journal.

A brief abstract (summary) of the report on the study in the Lancet Infectious Diseases may be seen here.

Between March 13, 2016, and Feb 14, 2017, 192 volunteers were enrolled into four age groups (adults [18–50 years; 20 male and 28 female], adolescents [11–17 years; 27 male and 21 female], children [5–10 years; 15 male and 33 female], and young children [1–4 years; 29 male and 19 female]) with 48 participants in each group.
All participants were Bangladeshi. Side effects where mild, with some patients developing rashes, fevers, or body aches.
Testing showed that adults, adolescents and children in all four groups who injected with the vaccine showed antibodies (resistance) to 4 different types of dengue and that this protection remained active so for three years.

Senior scientist at the icddr,b Rashidul Haque said, “The development of an effective and tetravalent dengue vaccine is a high priority for the large population of Bangladesh, which is now having increasingly severe dengue outbreaks.”

“We are proud to participate in the evaluation of the TV005 vaccine in the Bangladeshi population and hope that our work will accelerate the development of dengue vaccines for our country.”

The TV005 vaccine is the only single-dose tetravalent dengue vaccine, which is an important feature of this vaccine,” said another scientist, Beth Kirkpatrick, who led the University of Vermont team, adding that it also appears to prompt immune responses to all four of the dengue serotypes.

The single-dose vaccine, TV005, demonstrated safety and immune responsiveness in children and adults, tested effective against all the four dengue serotypes, according to the study published in The Lancet Infectious Diseases journal on Wednesday.

Scientists from the International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR, B), a Dhaka-based international health research organization, and the Larner College of Medicine at the University of Vermont conducted the study, the ICDDR, B said in the statement.

However, there are several dengue vaccines in development, with two commercially available and a single successful trial is just one step for the latest contender.

One of the main challenges of developing a dengue vaccine is antibody-dependent enhancement (ADE) — a person with low levels of antibodies against one serotype of dengue, may end up getting a more severe infection with another serotype of dengue.

This was what led to controversy surrounding the first dengue vaccine to be approved. Only after a vaccination programme had been rolled out in the Philippines, it was found that the vaccine could actually increase the risk of severe disease in people who had not been infected before.

Dengue fever, a mosquito-borne virus, is spreading throughout the world, especially in tropical regions. Mild cases cause fever and bone pain, while serious ones are associated with shock, bleeding, and sometimes death.

At the present time there are severe epidemics of dengue in Sudan and in Bangladesh, but small outbreaks are common in the Caribbean, particularly in Puerto Rico and St. Lucia. Most islands in the Caribbean have health programs to suppress the breeding of mosquitos in marshy areas and to remove standing water close to homes.

The mainland of the US is generally free of dengue, and most cases that are reported are imported by travelers from overseas, but because the kind of mosquitos that spread dengue are common in the US, it is still possible that it could spread as an epidemic in the US.

Source: Bangladesh Star, Lancet infectious diseases, CDC.
- Advertisement -