Dengue vaccines should be available on the market in 201513/09/2012
Over the past 50 years, the number of dengue cases in the world has multiplied. The World Health Organization (WHO) estimates that there are 200 million new cases per year. To try to reverse the situation, several groups of scientists around the world devote time, money and effort into producing a vaccine: an immunobiological substance able to fight all four serotypes at one time.
According to Mitermayer Galvão dos Reis, SBMT vice president, four vaccines have already gone through preclinical testing and are just waiting for human trials to evaluate the result. “The most advanced vaccine is Sanofi, which is developed with recombinant DNA. But, also under development are: a vaccine by Bio-Manguinhos in partnership with GSK, using dead virus; another one, with genetically modified virus, developed at the Butatan Institute and also, one by Merck”, says the specialist who is also the Director of Fiocruz in Bahia.
Given the extent of the disease and the economic potential of a future vaccine, studies have mobilized organisations such as the Butantan Institute in São Paulo, and the Oswaldo Cruz Foundation (Fiocruz) in Rio de Janeiro. As regards public research, the Butantan Institute has announced that it has found a vaccine and forecasts that it will come to market in 2015. According to the Institute, the vaccine, developed in partnership with the US National Health Institutes, has been tested in North America and is safe. Butatan predicts the first phase of testing will take place by the end of 2012.
Currently, the vaccines must pass through phases 1,2 and 3. First, the reactions and safety are checked, then the production of protective antibodies. If proven, the last step is to test it on people in different parts of the world”, says Mitermayer, who says one must take into account the different genetic characteristics of populations.
According to Dr. Akira Homma, chairman of the Political and Strategic Board of Bio-Manguinhos/Fiocruz, the vaccine that is being developed in Biomanguinhos should have completed phase 1 clinical studies by the first quarter of next year. “We are currently organizing epidemiological studies in communities in Fortaleza, Manaus, Salvador and Rio de Janeiro, in order to understand in more detail the incidence of dengue in these different communities”, he says. Akira Homma believes that when you reach the stage of clinical trials in the country, certainly, these locations will have a greater chance of being selected.
Akira Homma says that as the new vaccine strategies for dengue in the world are still in preclinical or clinical trials stages, it would be premature to say which would be the best or has the greatest potential for immunization. “The approach of the tetravalent vaccine of the inactivated virus, purified against dengue, proposed by Fiocruz and GSK, formulated with its own adjuvant systems seems to have a higher probability of success, since it does not cause viral interference, enables a shorter immunization/faster schedule protection and enables a less complex development process than a live attenuated vaccine”, he says. He points out that there is already another inactivated flavivirus vaccine, with optimal efficiency and low reactogenicity: the vaccine for Japanese encephalitis.
He explains that the agreement, finalized in 2009, provides a comprehensive program of joint research and development for an inactivated dengue vaccine, able to fight the four serotypes. “This is not exactly a technology transfer, although there is a component of the agreement with this feature. This agreement will enable an intensive exchange of information and technology, because Fiocruz and GSK will work in the development units in Brazil and Belgium, where GSK’s vaccines division is headquartered”, he explains.
Despite ensuring that he does not have data to make a more accurate assessment of the economic issue, about the price of the vaccine, Dr. Akira ensures that both Fiocruz and GSK are committed to ensuring that the cost is not a barrier for epidemic areas in Brazil and the world.” He thinks that once the effectiveness of the immunobiological substance is proven, and considered feasible and safe by the Ministry of Health (MOH) and the National Health Surveillance Agency (ANVISA), it will be part of the vaccination schedule.
Sanofi is already testing vaccine in humans
In the private sector, the French laboratory Sanofi-Pasteur forecasts that production will begin between 2014 and 2015 of the candidate vaccine that it has been testing in 13 countries in Asia, the United States and Latin America (including Brazil).
Sanofis vaccine has generated an immune response to four strains, but there has only been evidence of its effectiveness against three of them. Sanofi says it has been conducting tests to understand the resistance to the fourth kind. Phase 3 of the study includes 31,000 participants.
Sanofi Pasteur, the vaccines unit of the laboratory, has invested 350 million Euros (US$ 423 million) in a new factory in France to produce the vaccine, which is administered in three doses. The company expects an annual turnover of 1 billion euros with the product.
Dr. Akira believes that one must be open to the development of new vaccine products. “It is very important because it opens a whole new field of research, quite innovative in terms of science and technology and will probably have a huge impact on public health”, he stresses.
* Interview featured the contribution of Dr. Eduardo Ortega and Dr. Cristina Possas