The immunization status of children with chronic neurological disease and serological assessment of vaccine-preventable diseases

The aim of this study was to evaluate the age-appropriate immunization coverage in 366 children with chronic neurological disease (CND), to evaluate the use of vaccines not included in routine program, to evaluate serological tests for vaccine-preventable diseases and to describe the related factors in unvaccinated children. 95.6% of all children with had received age-appropriate vaccinations according to the actual National Immunization Program (NIP) during childhood. 12 children (3.6%) had not received vaccines; only two had true contraindications. Because most of the vaccines have been implemented through the NIP for 10 years in Turkey, 88% of children required these new vaccines or booster doses. Moreover, 86.6% of the children and 92.6% of household contacts had no prior history of influenza vaccine. Furthermore, 88% of the patients had not received the varicella vaccine, and the anti-varicella IgG levels were only negative in 27.9%. In addition, 18.6% of the children were negative for anti-mumps IgG, 23.7% for anti-measles IgG, and 6.3% for anti-rubella IgG. Anti-HBs IgG level was 0-10 IU/L in 45.6% of the patients (most of them previously vaccinated) and 79.8% were negative for hepatitis A IgG antibodies. For pertussis infection, the antibody titers of 54.1% of patients were below the protective level, and 10% of patients had a prior acute pertussis infection. Therefore, it is suggested that children with CND should be evaluated for their vaccination status during their first and follow-up visits at certain intervals, and their primary immunization should be completed; moreover, many will need revaccination or booster doses.

Comparative impact of pneumococcal conjugate vaccines on pneumococcal meningitis according to underlying conditions

BACKGROUND

Several underlying conditions increase the risk of pneumococcal meningitis (PM) in childhood. Patients with these diseases are initially considered as an important target of pneumococcal conjugate vaccines (PCVs). Limited data are available for PM in children with underlying conditions. To understand the benefits of PCV7 followed by PCV13 in this vulnerable population, we analyzed the data for a large cohort of pediatric patients with PM in France from 2001 to 2014.

METHODS

We conducted hospital-based active surveillance with 227 pediatric wards working with 168 microbiology departments throughout France. Standardized inclusion criteria for PM were used and data were analyzed by a pre-PCV7, post-PCV7 and post-PCV13 period.

RESULTS

From 2001 to 2014, among the 1582 cases of PM, 62.5% were reported in children less than 2years old. Underlying conditions (n=255, 16.1%) accounted for 7.3% of the cases in these young children versus 30.8% for children ⩾2-18years old (p<0.001). After PCV13 implementation, PM cases decreased by 44.0% from 2009 to 2014, mainly in children without underlying conditions. Though the number of children with underlying conditions remained stable, their proportion among overall PM cases increased by 79.1%. Among children with underlying conditions, PCV7 serotypes, 6 additional PCV13 serotypes, additional 11 serotypes in PPV23 and other serotypes accounted for 24.5%, 14.7%, 25.0% and 35.8%, respectively (p<0.001). After PCV13 implementation, 50.0% of PM cases with underlying conditions and 37.9% without underlying conditions were caused by serotypes included in neither PCV13 nor PPV23.

CONCLUSION

Besides the reduced numbers of PM, its profile has changed, with an increase in cases in proportion of children with underlying conditions accompanied by a striking change in serotype distribution. This underlines the importance of detecting underlying conditions in children with PM in the PCV13 era.

Invasive pneumococcal disease after implementation of 13-valent conjugate vaccine

OBJECTIVE

To examine whether there is a different clinical profile and severity of invasive pneumococcal disease (IPD) in children caused by nonvaccine types in the era of 13-valent pneumococcal conjugate vaccine (PCV13).

METHODS

Observational study of childhood IPD in Massachusetts based on state public health surveillance data comparing pre-PCV13 (2007-2009) and post-PCV13 (2010-2012) eras.

RESULTS

There were 168 pre-PCV13 cases of IPD and 85 post-PCV13 cases of IPD in Massachusetts children ≤5 years of age. PCV13 serotypes declined by 18% in the first 2 years after PCV13 use (P = .011). In the post-PCV13 phase, a higher proportion of children were hospitalized (57.6% vs. 50.6%), and a higher proportion of children had comorbidity (23.5% vs. 19.6%). Neither difference was statistically significant, nor were comparisons of IPD caused by vaccine and nonvaccine types. Children with comorbidities had higher rates of IPD caused by a nonvaccine type (27.6% vs. 17.2%; P = .085), were more likely to be hospitalized (80.4% vs. 50%; P < .0001), and were more likely to have a longer hospital stay (median of 3 days vs. 0.5 days; P = .0001).

CONCLUSIONS

Initial data suggest that nonvaccine serotypes are more common in children with underlying conditions, who have greater morbidity from disease. In the post-PCV13 era, a larger proportion of patients are hospitalized, but mortality rates are unchanged. Routine vaccination with PCV13 may not be enough to reduce the risk in patients with comorbidity.