New dengue vaccine expected in Tanzania soon

HILDA MHAGAMA and Agencies

TANZANIA and other countries may benefit from dengue fever vaccine which has been developed by a French pharmaceutical company, Sanofi.

As there has never been any vaccine to prevent infection, a new drug called Dengvaxia was approved for use earlier last month in three countries namely Mexico, the Philippines, and Brazil, which documented about 1.4 million new cases of dengue in 2015.

This breakthrough is the result of over two decades of work involving 25 clinical studies in 15 countries around the world. Over 40,000 volunteers worked on the project and some 29,000 volunteers received the vaccine. Though other vaccinations are currently in development, only Dengvaxia has been given the green light.

Sanofi’s facilities are reportedly capable of producing 100 million vaccine doses annually. “Approval of the first dengue vaccine is an important public health breakthrough with critical importance to our country, which bears the greatest dengue burden in Latin America,” noted Mr Joao Bosco from Brazil’s Institute of Tropical Pathology and Public Health in a Sanofi statement.

Mr Bosco said the 2015 dengue outbreak was still very present in the minds of Brazilians so Dengvaxia’s approval was a most welcome addition to their ongoing dengue prevention efforts, adding that Brazil recorded more than 1.4 million cases of dengue in 2015.

In clinical trials the vaccine proved effective for about 65 per cent of participants aged 9 to 16 and it prevented 8 out of 10 hospitalizations and up to 93 per cent of severe dengue cases.

Dengvaxia can only be used on people age nine to 45 years old that live in areas susceptible to dengue fever. Unfortunately, the vaccine appears to be the least effective among those who need it the most, children under six.

In February 2014, the Ministry for Health, Community Development, Gender, Children and the Elderly notified the World Health Organization that dengue fever outbreak was spreading very fast in Dar es Salaam and neighbouring regions.

By the end of May 2014, the dengue fever outbreak had spread to seven regions on the mainland and two regions in Zanzibar.

The geographical distribution of cases and deaths was mainland (1,017 confirmed cases out of a total of 2,121 suspected cases including four deaths) and Zanzibar (one confirmed case out of eight suspected cases, and no deaths).

Ninety-nine of the cases of the mainland were reported from three districts of Dar es Salaam: Kinondoni, Temeke, and Ilala.

When contacted for comment about the matter, Chief Medical Officer, Prof Muhammad Bakari said he was not in a position to talk about the status of the disease and specifically the new vaccination.

The WHO’s immunization advisers will issue their recommendations for its use in April 2016 and by then more countries may join in allowing its use.

Dengue is transmitted by the bite of a mosquito infected with one of the four dengue virus serotypes. It is a febrile illness that affects infants, young children and adults with symptoms appearing 3-14 days after the infective bite.

Dengue is not transmitted directly from person-to-person and symptoms range from mild fever to incapacitating high fever, with severe headache, pain behind the eyes, muscle and joint pain, and rash.