Vaccine is almost 100% effective against chikungunya – 06/12/2023 – Health

A chikungunya vaccine bordered on complete efficacy in its ability to generate an immune system response against the infection. The vaccine was also safe, with low-risk side effects. The conclusions are from a survey published this Monday (12) in The Lancet.

The virus that causes chikungunya is transmitted by Aedes aegypti, even the mosquito that transmits dengue and zika. Fever, red spots, pain in the joints and head are some of the symptoms of the disease.

For the time being, there is no vaccine against the disease, but studies are being carried out to find out whether a model developed by the company Valneva can be effective in controlling the disease. Single dose, the vaccine consists of an attenuated virus that does not have the ability to infect cells. According to the pharmaceutical company, a part of the pathogen’s genome was deleted and, therefore, it was possible to develop the drug.

The data recently released in the scientific article are from one of these surveys. Signed by the Austrian subsidiary of Valneva, the survey was carried out in the United States, where 3,644 people started in the study and reached the end of the investigation. Among them, 362 underwent the analysis of the immune response: 266 had received the immunizer, while 96 had accessed the placebo.

In the group of those with immunizer application, 263 had their immune system induced to produce neutralizing antibodies against the virus after 28 days of application. The index was measured again 180 days after the beginning of the research, registering a 96% rate in continuing with the adequate level in the production of neutralizing antibodies.

The research also disclosed details about the safety of the drug. About half of the participants who took the vaccine had a side effect related to the drug. In the placebo group, that number was nearly a third. But most of the problems reported were simple: 1.5% of those in the vaccine group had more serious symptoms, compared with 0.8% in those with access to placebo.

Although the results are a good indication of the efficacy and safety of the vaccine, the study has an important limitation: it was carried out in a country where the disease is not endemic, in this case, the USA. This makes it not possible to fully observe the protection conferred by the drug. The location of the research also makes it difficult to conclude its effect on people who have already been infected by the virus, something pointed out as a weakness of the research.

Brazil, where there is a high incidence of the disease, is an example of a place that could overcome this bottleneck. The Butantan Institute is Valneva’s partner in the country and planned a survey with 750 Brazilian teenagers. According to a spokesperson for the institution, recruitment for the study was completed in February of this year, but there is still no forecast for disclosing the results.