Salivary antibodies induced by the seven-valent PncOMPC conjugate vaccine in the Finnish Otitis Media Vaccine Trial

Anu Nurkka,Mika Lahdenkari,Helena Käyhty,Arto Ai Palmu

doi:10.1186/1471-2334-5-41

Anu Nurkka, Mika Lahdenkari + Show 2 more

Open Access

https://doi.org/10.1186/1471-2334-5-41

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Abstract

BackgroundMucosal antibodies have been suggested to have a role in defence against pneumococcal infections. We investigated here the ability of a seven-valent pneumococcal conjugate vaccine, PncOMPC, to induce mucosal immune response.MethodsHealthy Finnish children (n = 111), a subcohort of the Finnish Otitis Media Vaccine Trial, were recruited and 56 of them were immunised with the PncOMPC at the age of 2, 4, and 6 months. At 12 months of age, 49 of them received the PncOMPC and 7 were vaccinated with the pneumococcal polysaccharide vaccine (PncPS) as a booster. The control group of 55 children received a hepatitis B vaccine at the same ages. Salivary anti-Pnc IgG, IgA, IgA1, and IgA2 antibodies to serotypes 6B, 14, 19F, and 23F were measured in both groups at the age of 7 and 13 months.ResultsSalivary anti-Pnc IgG and IgA were detected more often in the PncOMPC than in the control group. However, the difference between groups was significant only for 19F and 23F IgA concentrations at the age of 7 months. At the age of 13 months, antibody concentrations did not differ between PncOMPC and control groups. The rises in IgA concentrations between 7 and 13 months of age were mainly of subclass IgA1. Further, there is a clear trend that PncPS booster induces higher salivary anti-Pnc PS antibody concentrations than the PncOMPC.ConclusionWe found that PncOMPC can induce a mucosal IgA response. However, the actual impact of mucosal antibodies in protection against pneumococcal infections is not clear.

Highlights

Mucosal antibodies have been suggested to have a role in defence against pneumococcal infections
We explored the effect of pneumococcal polysaccharide vaccine (PncPS) as a booster
Anti-pneumococcal IgG in saliva Anti-Pnc PS IgG was detected at the age of both 7 and months very rarely, and there were no differences either in the proportion of positive samples or concentration between the PncOMPC and control groups except for serotype at 13 months; there were more anti-Pnc PS IgG positive samples in the PncOMPC than in the control group (Table 1)

Summary

Introduction

Mucosal antibodies have been suggested to have a role in defence against pneumococcal infections. The pneumococcal carriage is often harmless, it may lead to a local disease, e.g. to acute otitis media (AOM), sinusitis or to an invasive disease like pneumonia, meningitis or sepsis [3]. The presence of pneumococcus in nasopharynx induces salivary antibodies against pneumococcal proteins and polysaccharides already in infants [7,8], and pneumococcal conjugate vaccines evoke mucosal immune response [5,9,10,11,12,13,14,15]. In addition to invasive disease and pneumonia, pneumococcal conjugate vaccines prevent local infections like AOM and carriage [16,17,18,19,20,21,22]. In an animal model mucosal antibodies prevented the acquisition of pneumococcus [23]

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