Pneumococcal Immunization in Young Children with Chronic Heart Failure

Aim: To determine the coverage, efficacy and tolerability of pneumococcal vaccination in young children with cardiovascular disease associated with chronic heart failure. Design: Retro- and prospective randomized comparative study. Materials and methods. The study included 250 patients at the age of 2 months to 5 years with confirmed chronic cardiac failure caused by cardiomyopathy or congenital heart disorder. Within the scope of a specialised laboratory and instrumental examination, all children underwent an assessment of specific immunoglobulin (Ig) levels to the most common pneumococcal serotypes (1-5, 6B, 7F, 8, 9N, 9V, 10A, 11A,12F, 14, 15B, 17F, 18C, 19F, 19A, 20, 22F, 23F, 33F) using VaccZyme Anti-PCP IgG test system. During consultations and vaccination schedule development, pneumococcal vaccination coverage and the reasons for long-term medical exemptions or refusals were analysed. Provided the primary disease was stable, there were no contraindications and a parent gave their consent, patients were vaccinated with 13-valent pneumococcal conjugate vaccine (PCV13). Results. When questioning the parents of patients, it was revealed that before admission to the department, only 97 (38.8%) patients received at least 1 dose of pneumococcal vaccine, while the remaining 153 (61.2%) were not vaccinated. During hospitalization, 65 (42.5%) of 153 unvaccinated patients under 5 years of age who had not received a single pneumococcal vaccine received the first dose (V1) of PCV13; of 97 children vaccinated, 20 (20.6%) received a second dose, 18 (18.6%) — pneumococcal booster. There was a significant difference in the levels of antibodies to Streptococcus pneumoniae between the group of patients who received a full course of immunization according to age and the group of unvaccinated children: 108.1 ± 58.4 vs. 12.14 ± 7.8 mg/l (p < 0.05). In children with an incomplete course of vaccination, the levels of specific IgG to pneumococcal serotypes were lower. In groups of children who received only one dose of the vaccine in the first or second year of life, they amounted to 42.2 ± 11.7 and 40.2 ± 16.2 mg/l, respectively. Children who received at least two doses of vaccine without revaccination (starting before 12 months) had a relatively higher level of 68.2 ± 6.3 mg/L. But, despite a clear trend, there was no significant difference between these groups in our study. In the post-vaccination period, no serious complications were recorded in the examined children. Conclusion. Vaccination against pneumococcal infection in children with chronic heart failure is effective, safe and should be carried out as close as possible to the schedule of the national vaccination calendar, with a limited set of contraindications. Keywords: vaccination, 13-valent pneumococcal conjugate vaccine, immunoglobulin G, chronic heart failure.