BRASÍLIA – The National Sanitary Surveillance Authority (ANVISA) has decided to contraindicate the dengue vaccine produced by Sanofi Pasteur for people who have never had contact with the virus. Under the new leadership of the agency, the vaccine should only be applied to people who have antibodies against one of the four subtypes of the virus that cause the disease. Immunization should also only be applied in cities where dengue is considered endemic – at least 70% of the population has had contact with the agent.
With the decision, the agency has raised the warning tone about the immuniser, registered in the country since 2015 and with distribution starting in 2016. The change takes place nine months after a work produced by the manufacturer, which showed that people who never contact with the virus, gave a risk of 0.5% hospitalization for dengue complications and 0.2% of the development of the severe form of the disease.
At that time, the agency had already noticed a change in the bull. At the time, however, there was only a recommendation that the vaccine should not be given to people who had never had contact with the virus. In April it was the turn of the World Health Organization give a warning about restrictions on the use of the vaccine.
"This change is part of the improvement process," said Alessandra Bastos Soares, director of the permit and health records. According to the director, there have been no changes so far in the studies of the risks of the vaccine for people who have never had the disease. "The indicators remain, only a more detailed assessment of the work has been done."
In Paraná the dengue vaccine was used in campaigns of the public network. In the rest of the country it is only available in private clinics. According to Anvisa, 350,000 people were vaccinated with the immunization produced by Sanofi Pasteur since the product arrived in the country. Data reported by the industry to the agency reported that there were 128 cases of serious adverse reactions.
The medical director of Sanofi Pasteur, Sheila Homsani, however, ensures that the side effects are not related to the use of the vaccine. She says that during the evaluation period all problems are seen with which people who have been immunized with Dengvaxia (the trade name of the immunizing agent) are reported. "They are on this list of harmful effects, for example people who have died from drowning," he says. According to Sheila, Brazil is the first country to contraindicate the vaccine for people who have never had contact with the virus. Elsewhere there is only one recommendation.
For the chairman of the Brazilian Immunity Association, Isabella Ballalai, the change is appropriate. "It is clearer, especially for the health professional," he says.
Paraná health secretary Antonio Carlos Nardi said that the recommendation does not change the state's strategy. New initiatives to complete the immunization schedule will be made. "Vaccination was recommended for 30 municipalities with the highest number of clinical cases of the disease. We keep track of what accompanies Anvisa," he says.
Anvisa said in his Thursday statement that the vaccine itself does not cause dengue or the severe form of the disease. The risk of serious cases is limited according to the study to people who have never had contact with the virus. "It is not the ideal vaccine, the protection level is 76%", says Isabella. However, she concludes that for places where the prevalence is high and the person has already had the disease, the recommendation can be made.
Anvisa recommends that people who have already taken one of the doses ask health experts to know if it is advisable to terminate the vaccination schedule, which consists of three doses. According to Anvisa, the monitoring of people who have been immunized by the company will be maintained.