Scientists close in on vaccine for dengue

Dar es Salaam. Drug giant Sanofi Pasteur is reportedly on the brink of developing a vaccine for dengue fever, which claimed five lives in Tanzania last month and put public health experts on high alert.

Announcing the breakthrough this week, the China-based drug manufacturer said the vaccine might be ready by the end of next year. Straits Times of Singapore reported last week.

If the vaccine’s efficacy is proved, it will save the lives of 50 million to 100 million people, according to the estimates of the World Health Organisation (WHO).

The outbreak of dengue in Dar es Salaam and other parts of the country grabbed the headlines, forcing public health experts to take urgent measures to contain the disease. The Health ministry then announced that over 370 people had been diagnosed with the disease this year. Four died, including a doctor at Temeke hospital who attended to the patients.

The government has allocated Sh500 million in efforts to eliminate dengue fever, which has spread fear among residents of Dar es Salaam and other parts of the country.

The Head of the company’s Vaccine Unit, Mr Guillaume Leroy, said at a two-day summit of the Association of South East Asian Nations (ASEAN) that clinical trials to test the effectiveness of the vaccine indicated success. The meeting was held in the Philippines two weeks ago. It would be the world’s first dengue vaccine, the Straits Times reported earlier this week.

But minister for Health Seif Rashid told The Citizen on Sunday that, the promising development notwithstanding, it was too early to celebrate as the vaccine was still subject to a long chain of tests before it is approved by WHO.

“WHO will notify us of the new development if the vaccine is tested and approved,” Dr Seif said on the phone. Even after WHO approves the vaccine, he added, it will be subject to approval by the Tanzania Food and Drugs Authority (TFDA).

In the trial, dengue cases in the group of about 10,000--including participants from Indonesia, Thailand and Malaysia--fell by more than half after the vaccine candidate was administered.

Another trial involving more than 20,000 people is underway in Latin America. “We are at a very critical milestone,” Mr Leroy said. “By the end of the year, we will have a full analysis of all the results.”

The outcome of these latest trials brings Sanofi Pasteur a step closer to a goal that has been more than 20 years in the making.

The company’s work has been hampered by the fact that dengue has four different strains. All must be effectively subdued before any vaccine can be counted a success, which the company said it has managed to do. Dengue is the fastest spreading vector-borne viral disease, according to the World Health Organisation, and is endemic in over 100 countries. Four in 10 people are at risk of getting infected.

There have also been a number of cases reported in Africa and Tanzania in particular. The deputy minister for Health and Social Welfare, Dr Stephen Kebwe, told Parliament recently that his ministry was embarking on a massive plan to fight the disease and ordered all buses travelling up-country from Dar es Salaam be fumigated to stop the disease from spreading to other regions.