The National Health Surveillance Agency (Anvisa) authorized the start of the phase III clinical trial of the tetravalent influenza vaccine, produced by the Butantan Institute. “The study aims to evaluate the safety, immunogenicity and consistency of the immune response in the vaccine batches”, informed Anvisa. In 2019, the agency had already authorized the clinical trial for the initial version of the vaccine’s clinical protocol. Due to the covid-19 pandemic, the trial only started in 2021. In 2022, Butantan announced the interruption of the study, before having completed the number of participants required. The trivalent vaccine against influenza from the Butantan Institute is already used in the campaigns of the Ministry of Health’s National Vaccination Program. production of the tetravalent vaccine, according to Anvisa, is similar to that of the trivalent vaccine. However, while one of the trivalent vaccines contains the B virus (Yamagata lineage – TIV-Y-IB) and the other contains the influenza B virus (Victoria lineage – TIV -V-IB) , the tetravalent has the two strains of strain B in the same formulation. “It is expected to obtain a vaccine analogous to the trivalent one, but with additional protection against a second B strain, determined seasonally by the World Health Organization. The addition of the second B strain of influenza (fourth strain in the vaccine) occurred in the transition from the seasonal bivalent to the trivalent vaccine following the H1N1 influenza pandemic,” the agency reported.
Agência Brasil
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