The chikungunya vaccine developed by the Butantan Institute and the French-Austrian company Valneva produced neutralizing antibodies in 98.8% of adolescents participating in the clinical trial carried out in Brazil, says the São Paulo institution.
The study, celebrated by researchers who follow it, also identified that the vaccine is safe, presents no points of concern and has adverse reactions that vary from mild to moderate, such as sensitivity at the injection site, headache, fever and fatigue.
“The data is excellent and shows that we are on the right path. It is a safe vaccine with a high capacity to induce protective antibodies”, says the director of the Butantan Institute, Esper Kallás.
“We are optimistic that, respecting all stages of studies and validation by regulatory bodies, we will be able to offer this vaccine to protect people from this disease that unfortunately affects the country”, he also says.
The virus that causes chikungunya is transmitted by Aedes aegypti, even the mosquito that transmits dengue and zika. Fever, red spots, joint and head pain are some of the symptoms of the disease. The pain lasts a few days, but can persist for months, even years.
For the FDA (USA food and drug regulatory agency), responsible for approving the use of the vaccine in the North American country, chikungunya “is an emerging threat to global health, with at least five million cases of infection” by viruses recorded during the last 15 years.
Approved last week in the USA for use in adults, the vaccine is studied for the first time in a country where the disease is considered endemic. In total, 750 adolescents participate in phase three of the Brazilian clinical trial.
The Butantan Institute wants to submit the results obtained to Anvisa (National Health Surveillance Agency) in the first half of 2024, in order to request authorization so that the product can be used in Brazil. The findings will also be shared with the European regulatory agency.
Valneva’s vaccine consists of an injectable dose and contains an attenuated version of the chikungunya virus, a frequently used immunization technique. The vaccine is the first in the world to be approved to combat the virus.
In Brazil, the clinical trial led by Butantan brings together young people aged 12 to 17 who live in endemic areas in the cities of São Paulo, São José do Rio Preto (SP), Salvador (BA), Fortaleza (CE), Belo Horizonte (MG ), Laranjeiras (SE), Recife (PE), Manaus (AM), Campo Grande (MS) and Boa Vista (RR).
Of the 750 who volunteered for the study, 500 received one dose of the vaccine, while another 250 took a placebo. The analysis of the immune response, carried out 29 days after application, showed that 98.8% of those who had never been infected with the chikungunya virus developed protective antibodies, compared to a rate of 100% among those who had previously been infected.
The induction of an immune response identified by Butantan is similar to the findings of studies carried out in the USA with the adult population: 98.9% of those who received the vaccine developed antibodies.
The partnership between Butantan and Valneva was closed in 2020. If the vaccine is approved, says the institute, it will be possible to produce and make the vaccine available in Brazil through the SUS (Unified Health System).
with BIANKA VIEIRA, KARINA MATIAS It is MANOELLA SMITH
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