Researchers from Butantan Institute work in a new vaccine for Covid-19, the disease caused by new coronavirus. According to a note published by the State Government on Monday (4), the initiative aims to produce an acellular solution, which stimulates the body’s immune response through the injection of organic membranes with proteins from the surface of the virus.
The vaccine is inspired by a mechanism observed in certain bacteria to deceive the immune system. They release vesicles that attract the action of antibodies and other cells related to the body’s defense. These membranes serve as bait to occupy the immune system while the bacteria are free to multiply.
Despite being a “distraction”, the vesicles stimulate the body’s immune memory. Butantan scientists intend to produce similar structures in the laboratory, but with proteins from the new coronavirus attached to them. The expectation that the vaccine can induce the body to create defense mechanisms against the specific activities of these viral proteins.
“The new technique allows formulations to contain a large amount of one or more antigens from the virus on a strongly adjuvant platform, inducing a more pronounced immune response”, explains Luciana Cezar Cerqueira Leite, a researcher at the Butantan Institute’s Vaccine Development Laboratory, Fapesp agency.
In practice, recombinant proteins from the new coronavirus are used to stimulate the production of antibodies specific for the antigen, while the outer membranes (also known as OMVs) serve as a support to “present” the proteins to the body, as well as to strengthen the immunological reaction.
“External membrane vesicles can modulate the immune response, in general, increasing and improving protection. In our case, we will use OMVs for a presentation of the antigen with strong built-in adjuvant power, which guarantees a better response”, points out Cerqueira Leite.
The development of the vaccine supported by the São Paulo State Research Foundation (FAPESP) and integrates a research platform that involves the study of vaccines for pertussis, pneumonia, tuberculosis and schistosomiasis using techniques associated with BCG vaccine – used to prevent forms severe tuberculosis in children and tested as a possible treatment for Covid-19 in other countries.
According to the note from the Government of So Paulo, in the face of the new coronavirus pandemic, a new line of research was created exclusively for the investigation of a vaccine against Covid-19.
Although the statement does not provide forecasts for the completion of the Butantan Institute study, researcher Cerqueira Leite points out that “around the world, and here in Brazil, different techniques are also being tested” and the body’s approach should “take longer to leave”. She stresses, however, the importance of developing multiple techniques simultaneously.
“We hope [as vacinas em desenvolvimento] work, but the fact that no one knows whether they will really protect. In this pandemic moment, do not try different strategies. Our approach will take longer to leave, but if those being tested do not work, we already have plans B, C or D “, says the researcher.