Pneumococcus polysaccharide protein coupling vaccine and its preparing method

Abstract

The present invention is pneumococus polysaccharide protein coupling vaccine comprising covalently connected pneumococus capsule polysaccharide and recombinant pneumolysin without hemolytic activity modification and its preparation process. The vaccine has pneumolysin without hemolytic activity as protein carrier, no need of eliminating hemolysis toxicity of pneumolysin with formalin and ensured safety, and may be used for infant below 2 yeas old to prevent tympanitis. Owing to the pneumolysin as the self protein, the vaccine has no probable immune interference reaction and strengthened immune protecting effect. The vaccine has cross immunizing protection effect on various kinds of serum type pneumococus and raised immune memory response to pneumococus infection.

Description

technical field [0001] The present invention relates to the category of novel vaccines in the field of biomedicine, in particular to the development of pneumococcal polysaccharide-protein conjugated vaccines using genetic engineering technology, and more specifically to pneumococcal polysaccharides with modified pneumolysin (protein) without hemolytic activity as the carrier Protein conjugate vaccine, its preparation method and application as otitis media vaccine. Background technique [0002] Otitis media (including acute otitis media (AOM) and secretory otitis media (OME)) is one of the most common diseases in infants and young children. It is an inflammatory disease of the middle ear caused by bacteria or viruses. Studies have found that more than 80% of children aged 2-3 have suffered from otitis media at least once, and about 17% of children have had 3 or more episodes of otitis media from birth to 6 months of age. From birth to 1 year old, 62% of children suffer from ...

AI Technical Summary

Problems solved by technology

The advantage is that it has a large number of valences and a wide range of protection, but studies have shown that this type of vaccine has the following problems: (1) Capsular polysaccharide is a T cell-independent antigen, although it can induce protective IgM antibodies after the initial vaccination, the effect is not effective. The price is not high, and re-vaccination cannot induce the required T cell memory and high-efficiency IgG antibodies; (2) The immune response produced is only effective against adult infection, but less effective against pneumococcal otitis media in children under 2 years old

However, the use of these two carrier proteins also has the following disadvantages: 1) the main antigenic component of this type of conjugated vaccine is the serotype capsular polysaccharide contained therein, and it is invalid for other serotype pneumococcal infections not included in the vaccine, That is, the lack of cross-immune protection effect; 2) may have immune interference reactions with diphtheria and tetanus vaccines that have been widely used in children's routine immunization

[0009] However, the disadvantage of pneumolysin proteoglycan conjugate vaccine is that pneumolysin has toxicity, that is, hemolytic activity

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