Haemophilus b conjugate vaccine(Sanofi)

Many of the inactivated viral vaccines for human and animal use are manufactured using formaldehyde as an inactivating agent. Apart from formaldehyde, Triton X-100 is also one of the chemicals commonly used in viral vaccine manufacturing. Triton X-100 is typically used to extract the cell-associated viruses and / or components during manufacturing process. The concentration of formaldehyde and Triton X-100 in the final bulks are also reduced during vaccine purification process. Here we report a simple RP-HPLC-UV based method for the quantification of residual Triton X-100 and formaldehyde as process impurities in viral vaccines. This method is also adopted for the residual impurity determination of either formaldehyde or Triton X-100 in other non-viral vaccines, multivalent as well as sub-unit vaccines, such as liquid pentavalent, includes TT, DT, Hepatitis B (rDNA) and Haemophilus type b conjugate vaccine (adsorbed). This method is rapid and can quantify both Triton X-100 and formaldehyde in a single preparation with improved peak asymmetry. This new assay has a linearity range starting from 0.0625 to 1 µg/mL for formaldehyde and 0.625-10 µg/mL for Triton X-100. This method would be very useful for viral vaccine manufacturing and release.

Deficiencies of C2 and other components of the classical pathway of complement are associated with increased risk of infections with encapsulated bacteria, such as Haemophilus (H.) influenzae. Defense against H. influenzae is dependent on specific antibodies and complement, which mediate serum bactericidal activity (SBA) and opsonization. Due to lack of normal classical and lectin complement pathway function in C2 deficiency (C2D), SBA would have to depend either on the alternative pathway or on C2 bypass mechanisms. Here we studied SBA against H. influenzae type b (Hib) before and after vaccination in a group of C2-deficient persons, as the bactericidal capacity of antibodies in autologous complement in relation to vaccination has not been investigated at group level in C2D. Sera from 22 persons with C2D and 26 healthy controls were available. Out of these, 18 persons with C2D and all controls had been vaccinated with Act-HIB®. SBA against Hib bacteria was analyzed with autologous serum as the only complement source. Antibodies to Hib capsular polysaccharide had been analyzed previously. Concentrations of mannose-binding lectin (MBL) and other complement components were measured in serum. SBA of both C2-deficient persons and controls was significantly more efficient after vaccination (p = 0.002 and p < 0.0001, respectively). After vaccination, all but two C2-deficient sera and one control serum showed sufficient SBA (<50% surviving bacteria). Before vaccination, SBA of C2-deficient sera was negatively correlated to serum concentrations of MBL (lower proportion of surviving bacteria with higher MBL concentration; r = -0.55, p = 0.008). After vaccination, SBA of C2-deficient sera was negatively correlated to serum concentrations of IgG Hib antibodies (r = -0.56, p = 0.01). In conclusion, SBA against Hib in autologous serum is increased after vaccination in persons with C2D. In unvaccinated C2-deficient persons SBA was correlated to MBL concentration, providing further support for an MBL-dependent C2 bypass mechanism operating in C2D.