Sunday, 24 October, 2021

Govt has no plan to import dengue vaccine

  • Mohammad Al Amin
  • 12 October, 2021 12:00 AM
  • Print news

The government has no plan to bring the dengue vaccine or run any trial in the country at this moment as the only dengue vaccine approved by the World Health Organization (WHO) is expensive and not suitable for all.

Experts said the first dengue vaccine Dengvaxia was endorsed by the European Medicine Agency and the US Food and Drug Administration (FDA). The vaccine can be given only to people who had already been infected with the virus.

“I don’t know about the dengue vaccine. We have no initiative to bring it now,” Prof Dr ABM Khurshid Alam, director-general of the Directorate General of Health Services (DGHS) told the Daily Sun.

The DGHS earlier had carried out a feasibility study on the use of the dengue vaccine in Bangladesh and held a meeting with a delegation of Sanofi, the manufacturer of the vaccine in August 2019. But the move to import the vaccine didn’t move ahead as the authorities didn’t find it feasible here.

Talking to the Daily Sun, former DGHS director-general Prof Dr Abul Kalam Azad had said a dengue vaccine might cost Tk 5,000-6,000. He said the vaccine is not feasible in Bangladesh as it might be used only for the patients who are infected for a second time.

Talking to the Daily Sun, Dr. ASM Alamgir, principal scientific officer of the Institute of Epidemiology, Disease Control and Research (IEDCR), said, “The dengue vaccine can only be used for the patients diagnosed with dengue for the second time.”         

According to the WHO, Dengvaxia (CYD-TDV) is the first dengue vaccine to be licensed in the world. CYD-TDV is a live recombinant tetravalent dengue vaccine developed by Sanofi Pasteur (CYD-TDV), given as a 3-dose series on a 0/6/12 month schedule. It was first licensed in Mexico in December 2015 for use in individuals 9-45 years of age living in endemic areas, and is now licensed in 20 countries.

As described in the WHO position paper on the Dengvaxia vaccine (September 2018) the live attenuated dengue vaccine CYD-TDV has been shown in clinical trials to be efficacious and safe in persons who have had a previous dengue virus infection (seropositive individuals).

However, it carries an increased risk of severe dengue in those who experience their first natural dengue infection after vaccination (those who were seronegative at the time of vaccination).

For countries considering vaccination, pre-vaccination screening is the recommended strategy. With this strategy, only persons with evidence of a past dengue infection would be vaccinated (based on an antibody test, or a documented laboratory-confirmed dengue infection in the past). 

The WHO further said vaccination should be considered as part of an integrated dengue prevention and control strategy. There is an ongoing need to adhere to other disease prevention measures such as well-executed and sustained vector control. Individuals, whether vaccinated or not, should seek prompt medical care if dengue-like symptoms occur.

The European Medicines Agency (EMA) said Dengvaxia is only for people from 9 to 45 years of age who have been infected with the dengue virus before and who live in areas where this infection is endemic. Endemic areas are areas where the disease occurs regularly throughout the year.

Dengvaxia contains attenuated (weakened) yellow fever viruses that have been manipulated so that they contain proteins from the dengue virus.

The US, CDC, In May 2019, Dengvaxia was approved by the U.S. Food and Drug Administration (FDA) in the United States for use in children aged 9 to 16 years, with laboratory-confirmed previous dengue virus infection and living in an area where dengue is endemic (common).

In June 2021, the Advisory Committee on Immunization Practices (ACIP) recommended the use of Dengvaxia to prevent dengue in children aged 9 to 16 years, with laboratory-confirmed previous dengue virus infection and living in areas where dengue is common. Three doses of vaccine are required. Each shot is spaced six months apart, the US CDC added.

According to a report published in the Sanofi Pasteur, licensed for producing the dengue vaccine, the European Commission has granted marketing authorization for Dengvaxia, dengue vaccine in 2018.

Some other dengue vaccines also are now in the trial process like LATV by NIAID/Butantan/Merck, TAK-003 by Takeda, TDEN by U.S. Army Medical Research and Materiel Command, DPIV by U.S. Army Medical Research and Materiel Command, TVDV by U.S. Army Medical Research and Materiel Command and V180 by Merck.

Experts said that developing a viable vaccine against the dengue virus has proved difficult because the pathogen is four different virus types or serotypes. Unless a vaccine protects against all four, a vaccine can wind up doing more harm than good.

According to the WHO, dengue is a mosquito-borne viral disease and the dengue virus is transmitted by female mosquitoes mainly of the species Aedes aegypti and, to a lesser extent, Ae. albopictus.

Dengue is caused by a virus of the Flaviviridae family and there are four distinct, but closely related, serotypes of the virus that cause dengue (DEN-1, DEN-2, DEN-3 and DEN-4).

Recovery from infection by one provides lifelong immunity against that particular serotype. Cross-immunity to the other serotypes after recovery is only partial and temporary. Subsequent infections (secondary infection) by other serotypes increase the risk of developing severe dengue, it added.