Times of India
10 February 2011
By Kounteya Sinha
New Delhi, India

India To Join Phase–3 Of Tests; Shot Has Shown 90% Efficacy So Far
India could soon be part of a large global trial to test the world’s first effective vaccine against dengue. Drug controller general of India (DCGI) is studying a proposal from French vaccine makers, Sanofi Pasteur, to test their candidate vaccine’s effectiveness among Indians. This vaccine is the most advanced candidate, and is undergoing phase III trials – final stage of clinical development – in 10 countries.

Interestingly, the vaccine has shown over 90% safety and efficacy profile during the phase II trials. DCGI sources told TOI that "we have received a proposal from Sanofi to conduct a registration trial of their CYD tetravalent dengue vaccine in India. The proposal has been referred to our Investigations New Drug (IND) committee. They want to conduct a three–centre trial in the 2–45 age group."

Speaking to TOI from Lyon in France, Dr Jean Lang, who is associated with Sanofi’s endemic new vaccines programme, said the shot is likely to be available by 2015.

He added, "We should have a viable, effective and safe dengue vaccine by 2015. However, results of an efficacy trial ongoing in Thailand on 4,000 children will be a critical milestone in its development. Data from that will be available by the end of 2012."

According to Dr Lang, the global trial involves 30,000 people.
"In India, the two–year trial will involve 1,000 people. We will first try the three–shot vaccine on the 2–45 age group. After reviewing that result, we will use it on those between 9 months and 65 years. We want to see the immunogenicity response in Indians," he explained.

There is no vaccine available for dengue fever that is a threat to around three billion people, mostly in Latin America and Asia. This candidate vaccine targets all four virus serotypes circulating in the US, Asia and Latin America. Clinical studies (phase III) among adults and children are now on in Mexico, Colombia, Honduras, Puerto Rico, Peru, the Philippines, Vietnam, Singapore, Australia and Thailand.

"Thailand was selected because of high incidence of dengue. By selecting a country where it is endemic, we maximize the chances to generate statistically significant clinical data in a stringent environment. Hence, we will be able to demonstrate a clinically meaningful efficacy of the vaccine," he added.

Dengue is a mosquitoborne disease caused by four dengue virus serotypes – 1 to 4). Of the estimated 220 million people infected annually, two million – mostly children – develop dengue hemorrhagic fever (DHF). Globally, the projected number of annual dengue infections is estimated between 50–100 million, with 24,000 deaths, who are mainly children.