Pneumococcal conjugate vaccine primes mucosal immune responses to pneumococcal polysaccharide vaccine booster in Papua New Guinean children

Abstract

Introduction Invasive pneumococcal disease remains a major cause of hospitalization and death in Papua New Guinean (PNG) children. We assessed mucosal IgA and IgG responses in PNG infants vaccinated with pneumococcal conjugate vaccine (PCV) followed by a pneumococcal polysaccharide vaccine (PPV) booster. Methods Infants received 7-valent PCV (7vPCV) in a 0–1–2 (neonatal) or 1–2-3-month (infant) schedule, or no 7vPCV (control). At age 9 months all children received 23-valent PPV (23vPPV). IgA and IgG to 7vPCV and non-7vPCV (1, 5, 7F, 19A) serotypes were measured in saliva collected at ages 1, 2, 3, 4, 9, 10 and 18 months (131 children, 917 samples). Correlations were studied between salivary and serum IgG at 4, 10 and 18 months. Results Salivary IgA and IgG responses overall declined in the first 9 months. Compared to non-7vPCV recipients, salivary IgA remained higher in 7vPCV recipients for serotypes 4 at 3 months, 6B at 3 months (neonatal), and 14 at 3 (neonatal), 4 and 9 months (infant); and for salivary IgG for serotypes 4 at 3, 4 and 9 months, 6B at 9 months, 14 at 4 (neonatal) and 9 months, 18C at 3, 4, and 9 (infant) months, and 23F at 4 months. Following 23vPPV, salivary 7vPCV-specific IgA and IgG increased in 7vPCV-vaccinated children but not in controls; and salivary IgA against non-PCV serotypes 5 and 7F increased in 7vPCV recipients and non-recipients. Salivary and serum IgG against 7vPCV-serotypes correlated in 7vPCV-vaccinated children at 4 and 10 months of age. Conclusions PCV may protect high-risk children against pneumococcal colonization and mucosal disease by inducing mucosal antibody responses and priming for mucosal immune memory that results in mucosal immune responses after booster PPV. Saliva can be a convenient alternative sample to serum to study PCV-induced systemic IgG responses.

The Enigmatic Voyage of Pneumococcal Carriage: Unraveling the Risk Factors in Pediatric Populations -- A Scoping Review.

“…The most common serotypes recorded from the listed countries were serotype 6A cases recorded from New Guinea (2023) [31], Thailand (2023)[80],Nigeria (2023)[81],Bangladesh & India (2021) [46], Ecuador (2021) [70], and the Dominican Republic (2021) [70]; serotype 19A cases reported from the Nigeria (2023) [31,81], Thailand (2023) [80],New Guinea (2023) [31],Dominican Republic (2021), Bangladesh (2021) [46], India (2021) [46], Ecuador (2021) [70], and Malawi (2022); serotype 1 cases reported from Kenya (2012 [89, 90], 2017 (52,83)) and Nigeria (2018); serotype 5 cases reported from Nigeria (2018) [75], Vietnam (2021), Germany (2021)[67], and Kenya (2012[89, 90], 2017 [29]); and serotype 7F cases reported from Vietnam (2021) [77], Germany (2021)[67], and Kenya (2012 [89, 90], 2017) [89,90]. There is a considerable increase in PCV13 serotype numbers in 2020 and 2021.…”

“…One of the most important methods for avoiding pneumococcal illness is vaccination with PCVs. In certain studies, persons without a vaccine [38,40,46,83,85,[91][92][93][94] or with partial immunizations [31,36,42,45,47,[52][53][54][55][56][57][58][59][60][61][62]79, 81] had a higher frequency of the disease than those who were vaccinated. This highlights the importance of vaccination initiatives in reducing the incidence of pneumococcal disease.…”

The clinical relevance of IgM and IgA anti-pneumococcal polysaccharide ELISA assays in patients with suspected antibody deficiency

“…Secondly, anti‐PnPS IgA and IgM were only measured in blood, not in mucosal tissues or secretions. While the PCV and PnPS vaccine, after priming with PCV, have been shown to be able to induce protective mucosal IgA antibodies [ 27 , 28 ], it is unknown whether this also occurs after immunization with PnPS vaccine alone. Most infectious pathogens enter the host via mucosal surfaces, where mucosal IgA represents the hallmark of immune responses [ 29 ].…”

Effects of Probiotic Mixture Supplementation on the Immune Response to the 13-Valent Pneumococcal Conjugate Vaccine in People Living with HIV

“…With regard to salivary IgA antibody, we observed a difference between the groups, with a higher post-vaccination increase in salivary IgA in Vivomixx ® supplemented patients, in accord with the study of Lue et al showing that, of all classes of anti-CPS antibody in saliva and tears, PPV levels increase the most. The authors reported a 2.0-fold increase of salivary IgA levels detected in the saliva of PCV-immunized children [32,33] as result of an immunostimulatory effect of probiotic bacteria [34,35].…”