Biologist develops nasal vaccine against hepatitis B

Method uses the chitosan polymer produced from chitin. Substance is found in camaões and crabs

Research has proven the feasibility of using chitosan polymer in vaccine production Dispensing needles for your aplicação.Uma new form of immunization (intranasal) was developed from the vaccine against hepatitis B, available on the Institute Butantan.O polymer coats the vaccine antigen, ensuring its absorption by the organism to be applied intranasally. The idea was to create a model that could be adapted to other vaccines, says biologist Jony Yohsida Takao, who conducted the research at the Faculty of Pharmaceutical Sciences (FCF) of USP.

In the production of the vaccine was employed chitosan polymer produced from chitin. This substance is found in arthropods such as shrimp and crab, says the biologist. Chitosan involves the vaccine antigen, which may be a protein or a virus. When vaccination is performed, the polymer sticks to the nasal passages, allowing antigen uptake by the body and the development of antibodies.

Chitosan prevents the vaccine is expelled from the body through sneezing after application. The vaccine is not swallowed by the renewal of the nasal mucus, preventing it from being destroyed by stomach acids, says Yoshida. Tests carried out on mice have shown that it is possible to immunize nasally with the use of chitosan.

According to Yoshida, the main advantage of intranasal immunization is to dispense with the use of needles to perform immunization. Many people are afraid to take injection. The new method would increase adherence and effectiveness of vaccination among the population, he says. The disposal of needles also reduce the risk of contamination between healthcare professionals.

Animal experiments also demonstrated that the polymer can be linked to any other protein. Thus, antigens can be used for other diseases, says the biologist. The vaccine may be applied by means of spray or mist.

For the vaccine to be used in humans, further studies are needed. The research proved that the method is feasible. However, you must perform clinical and immunological tests, first in animals and then in humans, to verify that there are no side effects, says the biologist. Despite the low cost of the raw material polymer, there is need for standardization and quality control to verify the feasibility of industrial production.

The new research also define the dosage and quantity of necessary immunizations nasally. In the United States approved a vaccine against influenza that is used as a nasal spray route of immunization and there are many researches on this type of immunization, says biologist. In Brazil, according to the Ministry of Health, there were 120 343 cases of hepatitis B per year between 1999 and 2011, with an average of 14,000 new cases and 500 deaths per year.