The trial includes 2 stages (Stage I and Stage II). The aim of the Stage I is to assess the tolerability, reactogenicity and safety of the Hib vaccine in the first 10 volunteers during the first 7 days after vaccination.~The aim of the Stage I is to assess the tolerability, reactogenicity and safety of the Hib vaccine during 28 days after vaccination and also to conduct a comparative assessment of the safety and reactogenicity of the Hib vaccine and placebo during 28 days after vaccination.
Trial purpose is to evaluate the safety, tolerability and reactogenicity of the Vaccine for the prevention of infections caused by Haemophilus Influenzae Type b in volunteers aged 18-50.