The present article describes clinical signs of meningococcal disease. It justifies the necessity of its vaccine prevention. The article provides with the historical data on the evolution of inoculants from corpuscular inactivated vaccines to modern chemical polyvalent vaccines. It provides a glimpse of the efficacy of the use of corpuscular vaccines and considers the corresponding implications. The historical overview includes the use of mono-, di-, tetravalent polysaccharide vaccines, and the discussion on the role of bactericidal antibodies in the formation of immunity against meningococcal disease. The article also describes the experience of using polysaccharide vaccines in various countries and in different age groups in randomized clinical trials. It provides with the data analysis about the effect of vaccination on the level of meningococcal carriage and the incidence of meningococcal disease. The WHO’s position on the use of polysaccharide meningococcal vaccines in routine practice are also provided. In the conclusion the article presents the prospects for further use of polysaccharide vaccines to control the spread of meningococcal disease.

The article summarizes the existing knowledge on the infection caused by Haemophilus influenzaetypeb (Hib-infection). It examines clinical immunology aspects of vaccination against Hib-infection. The authors cite data on the incidence of invasive Hib-infections in the Russia and other countries. Special attention is given to preventive vaccination against Hib-infection. The article describes properties of polysaccharide and conjugate vaccines against Hib-infection and examines different immunization schedules, therapeutic indications and contraindications, potential adverse reactions, and the vaccination procedure.

Despite the progress in fighting against infectious diseases of bacterial origin, the incidence of generalized forms of meningococcal infection (GFMI) remains a topical public health problem not only in countries with historical high incidence, but also in countries considered to be relatively «secured» in regard to the mentioned infection. In the 60s of the last century the production of high-polymer forms of meningococcal polysaccharides was started. These high molecular weight polysaccharides were used for the development of vaccines. They helped to significantly reduce the incidence of GFMI in certain countries, including the countries of the so-called African «meningitis belt». Unfortunately, polysaccharide vaccines have well-known deficiencies, prompting the researchers to develop advanced conjugate vaccines. Current new generation of vaccines are based on conjugates of polysaccharides of different serogroups with carrier proteins such as tetanus toxoid, a modified diphtheria toxin (CRM197) or outer membrane proteins. Mono- and multivalent conjugate vaccines were developed and tested. Conjugate vaccines have several advantages compared to the polysaccharide vaccines. They stimulate the formation of immunological memory, and therefore are able to provide consistent protection against meningococcal disease in children of an early age group. In particular, monovalent conjugate vaccine against serogroup C meningococcal disease were proven to be very effective. This vaccine was successfully used in the UK. There are also tetravalent conjugate vaccines Menactra and Menveo. These preparations consist of serotype A, C, W135 and Y meningococcal polysaccharide conjugates. These polysaccharides stimulated the production of bactericidal antibodies in 90% of immunized individuals. Certain success was also achieved in developing genetically engineered vaccines and the vaccines based in meningococcal outer membrane vesicles (OMV-vaccines). OMV-vaccines showed to be effective in the fight against epidemics of meningitis caused by serogroup B meningococcus. Polysaccharide vaccines against serogroup B meningococcus in different designs proved to be ineffective because of their low immunogenicity. There are certain difficulties in developing an ultimate vaccine that protects against GFMI, due to the fact that there is a variety of antigenic types of serogroup B meningococcus. So far the scientists only have managed to develop a strain-specific vaccine suitable for fighting GFMI outbreaks, caused by the specific strain of serogroup B meningococcus. The opportunities to enhance the efficacy of vaccines against serogroup B meningococcus are still being discussed.

The article summarizes the existing knowledge on the infection caused by Haemophilus influenzae type b (Hib-infection). It examines clinical immunology aspects of vaccination against Hib-infection. The authors cite data on the incidence of invasive Hib-infections in the Russia and other countries. Special attention is given to preventive vaccination against Hib-infection. The article describes properties of polysaccharide and conjugate vaccines against Hib-infection and examines different immunization schedules, therapeutic indications and contraindications, potential adverse reactions, and the vaccination procedure.

Despite the progress in fighting against infectious diseases of bacterial origin, the incidence of generalized forms of meningococcal infection (GFMI) remains a topical public health problem not only in countries with historical high incidence, but also in countries considered to be relatively «secured» in regard to the mentioned infection. In the 60s of the last century the production of high-polymer forms of meningococcal polysaccharides was started. These high molecular weight polysaccharides were used for the development of vaccines. They helped to significantly reduce the incidence of GFMI in certain countries, including the countries of the so-called African «meningitis belt». Unfortunately, polysaccharide vaccines have well-known deficiencies, prompting the researchers to develop advanced conjugate vaccines. Current new generation of vaccines are based on conjugates of polysaccharides of different serogroups with carrier proteins such as tetanus toxoid, a modified diphtheria toxin (CRM 197 ) or outer membrane proteins. Mono- and multivalent conjugate vaccines were developed and tested. Conjugate vaccines have several advantages compared to the polysaccharide vaccines. They stimulate the formation of immunological memory, and therefore are able to provide consistent protection against meningococcal disease in children of an early age group. In particular, monovalent conjugate vaccine against serogroup C meningococcal disease were proven to be very effective. This vaccine was successfully used in the UK. There are also tetravalent conjugate vaccines Menactra and Menveo. These preparations consist of serotype A, C, W 135 and Y meningococcal polysaccharide conjugates. These polysaccharides stimulated the production of bactericidal antibodies in 90% of immunized individuals. Certain success was also achieved in developing genetically engineered vaccines and the vaccines based in meningococcal outer membrane vesicles (OMV-vaccines). OMV-vaccines showed to be effective in the fight against epidemics of meningitis caused by serogroup B meningococcus. Polysaccharide vaccines against serogroup B meningococcus in different designs proved to be ineffective because of their low immunogenicity. There are certain difficulties in developing an ultimate vaccine that protects against GFMI, due to the fact that there is a variety of antigenic types of serogroup B meningococcus. So far the scientists only have managed to develop a strain-specific vaccine suitable for fighting GFMI outbreaks, caused by the specific strain of serogroup B meningococcus. The opportunities to enhance the efficacy of vaccines against serogroup B meningococcus are still being discussed.