Sanofi Pasteur on April 15, 2016, announced the approval of a vaccine for dengue to be used in endemic countries by World Health Organization (WHO). The corporation holds the patent for first ever licensed vaccine Dengvaxia (CYD-TDV) for dengue.
“These WHO SAGE recommendations further validate the scientific and medical value of Dengvaxia® and send a clear message to endemic countries about the strong public health benefit to be gained by introducing the dengue vaccine in integrated disease management efforts to combat their dengue burden,” President of Global R&D, Sanofi, Elias Zerhouni, MD, said in a statement.
The move came after the Strategic Advisory Group of Experts on Immunizations (SAGE) submitted their recommendations to WHO after a meeting in Geneva.
Before this WHO only recommended dengue control and prevention method based on effective vector control methods. Measures such as environmental management and modification, vector control through community outreach, participation and mobilization were advised.
SAGE advised the use of the vaccine in the countries with prevalent dengue infections to adopt it as a part of integrated disease prevention strategy. The panel also recommended the use of an effective communication strategy, reliable dengue surveillance, best clinical care for dengue patients, and a sustainable vector-control programme.
When Health Units asked what were his views on the SAGE recommendations to WHO regarding the approval of Dengvaxia, Dr Donald Shepard said, “The recommendations based on seroprevalence make sense. I endorse them.”
The recommendations were based on data from 25 different clinical studies conducted in nearly 15 endemic and non-endemic countries in the world, with almost 40,000 participants. Dengvaxia is recommended to be used in individuals with 9-16 years of age.
According to the corporation’s media statement, the vaccine prevented 8 out of 10 hospitalizations, 93 percent of severe cases of dengue and reduced dengue to two-thirds of the total participants, in all of the four serotypes.
“Successful introduction of dengue immunization alongside other prevention efforts should help endemic countries achieve the WHO objectives to reduce dengue morbidity by 25 percent and mortality by 50 percent by 2020,” Sanofi also said in the statement.
Other vaccines under development include a live attenuated vaccine from NIH, DNA dengue vaccine from US Naval Medical Research Center, purified inactivated vaccine with novel adjuvants from GlaxoSmithKline, and an adjuvanted recombinant envelope protein vaccine from Merck.
A Vaccine Position Paper will be published in July 2016, highlighting the WHO international recommendations for dengue.
An increase in the global economic burden of dengue has been observed in the previous years. The global dengue virus infections were estimated at 58.40 million cases including the 13,586 deaths in the year 2013. But just in two years the total symptomatic dengue patients worldwide increased between 67 million to 136 million, according to WHO.
WHO also reported that, in 2015, Brazil alone reported 1.5 million cases which were three times higher than in 2014. Philippines reported more than 169,000 cases and Malaysia exceeded 111,000 suspected cases of dengue, which is a 59.5 and 16 percent increase than the previous year, respectively.
The latest research effort to estimate the global economic burden of dengue was led by Dr Donald Shepard and his team, which published their findings in Lancet, on April 15, 2016.
The professor who is currently affiliated with Schneider Institutes for Health Policy, Heller School for Social Policy and Management, and Brandies University in the State of Massachusetts, analyzed data from 141 countries using the incidence statistics estimates from the ‘Global Burden of Disease Study 2013’, and estimated that nearly $8.9 billion are spent globally on this prevalent disease. The study was sponsored by Sanofi Pasteur.
Dr Shepard gave his opinion that ‘recent estimates indicate that while the number of symptomatic cases is probably at the bottom end of the range reported by WHO, the growth is worrying, with several countries reporting record outbreaks within the last five years’, according to Infectious Disease News.
Dr Shepard proposed the use of prevention strategies to reduce the incidence of the dengue and save billions of dollars that are spent every year on the disease.
Dengue has four distinct serotypes (DEN-1, DEN-2, DEN-3, and DEN-4) that can cause nearly 390 million infections each year with no specific treatment designed for dengue in existence.
Aedes Aegypti: A Vector For Dengue And Zika Virus
Dengue is transmitted by female Aedes Aegypti and can present itself with symptoms like a characteristic measles like rash, joint pain, muscle pain, fever, and headache which can sometimes develop into a severe illness with fluid accumulation, respiratory distress, organ impairment, severe bleeding and plasma leaking.
The same species of the mosquito, Aedes Aegypti, is linked to the transmission of Zika virus, which shows devastating effects in the newborn.
CDC reports the prevalence of the Aedes Aegypti, responsible for not only dengue and Zika but also for yellow fever virus and chikungunya globally throughout temperate, subtropical and tropical regions.
This situation is becoming increasingly alarming due to the recent reporting of Zika virus cases in America. Though none of the cases reported have been vector borne, the possibility of people who are already infected passing on the virus through the mosquito vector is increasing.
Currently 358 cases have been reported in US states, which were only acquired through travel to endemic areas.
If the mosquito Aedes starts the transmission of Zika in United States, it can potentially start a local epidemic because there is no cure available and the only strategy available right now is the preventive measures for vector control.
In America the mosquito is prevalent in California, Arizona, New Mexico, Texas, Louisiana, Arkansas, Kansas, Tennessee, Alabama, Mississippi, Georgia, Florida, South Carolina, North Carolina, Kentucky, Virginia, West Virginia, Maryland, Delaware and New Jersey.