Changing Trends of Invasive Pneumococcal Disease in the Era of Conjugate Pneumococcal Vaccination in Olmsted County: A Population-Based Study

Seroconversion following PPSV23 vaccination in children with type 1 diabetes mellitus

OBJECTIVE

To evaluate whether children with type 1 diabetes mellitus (T1DM) have optimal humoral immune response to pneumococcal polysaccharide vaccination (PPSV23) and to study factors affecting that response.

METHODS

In this prospective pilot study, we recruited 29 children with T1DM who were vaccine naïve to PPSV23 and assessed serum-serotype specific IgG at baseline and 4-6 weeks post-immunization. We tested association between independent variables (age, gender, body mass index (BMI), hemoglobin A1c (HbA1c), glucose variability, and time in range assessed by continuous glucose monitors (CGM), insulin dose and outcome (log-2-fold change of immunoassay response between pre- and post-immunization testing) using linear regression.

RESULTS

Eighty-eight percent of children (22/25) who completed the study had overall appropriate response with a median 4.2-fold change following immunization. When assessing PPSV23-exclusive serotypes, there was a statistically significant correlation between increasing age and greater response (0.16 log2-fold change per year, 95 % CI (0.014 to 0.3), p = 0.033). Higher BMI for age (p = 0.085) and a lower coefficient of glucose variation from CGM following immunization (p = 0.067) also coincided with greater vaccine response, with correlation statistically significant for certain pneumococcal serotypes for both.

CONCLUSIONS

Response to pneumococcal vaccination has not previously been assessed in children with T1DM, and our study demonstrates robust humoral immune response to PPSV23 vaccination in these children. Larger studies with a diverse representation and longer follow up to assess how humoral seroconversion correlates with clinical response to PPSV23 in this vulnerable population are warranted.

Outbreak of severe community-acquired bacterial infections among children in North Rhine-Westphalia (Germany), October to December 2022

PURPOSE

In late 2022, a surge of severe S. pyogenes infections was reported in several European countries. This study assessed hospitalizations and disease severity of community-acquired bacterial infections with S. pyogenes, S. pneumoniae, N. meningitidis, and H. influenzae among children in North Rhine-Westphalia (NRW), Germany, during the last quarter of 2022 compared to long-term incidences.

METHODS

Hospital cases due to bacterial infections between October and December 2022 were collected in a multicenter study (MC) from 59/62 (95%) children's hospitals in NRW and combined with surveillance data (2016-2023) from the national reference laboratories for streptococci, N. meningitidis, and H. influenzae. Overall and pathogen-specific incidence rates (IR) from January 2016 to March 2023 were estimated via capture-recapture analyses. Expected annual deaths from the studied pathogens were calculated from national death cause statistics.

RESULTS

In the MC study, 153 cases with high overall disease severity were reported with pneumonia being most common (59%, n = 91). IRs of bacterial infections declined at the beginning of the COVID-19 pandemic and massively surged to unprecedented levels in late 2022 and early 2023 (overall hospitalizations 3.5-fold), with S. pyogenes and S. pneumoniae as main drivers (18-fold and threefold). Observed deaths during the study period exceeded the expected number for the entire year in NRW by far (7 vs. 0.9).

DISCUSSION

The unprecedented peak of bacterial infections and deaths in late 2022 and early 2023 was caused mainly by S. pyogenes and S. pneumoniae. Improved precautionary measures are needed to attenuate future outbreaks.