Vaccine failures in pediatric cases caused by streptococcus pneumoniae serotype 19A

ABSTRACT

Community-acquired pneumonia (CAP) is a leading cause of childhood mortality and morbidity worldwide. PCV-13 has implemented incidence of CAP undoubtedly in a very good way but continuous surveillance for vaccine failures is still very important for future vaccination programs. To support this opinion we report seven children (age of the seven patients ranged between 10 months and 5 y, 10 months old patients were vaccinated 3 times with PCV13 whereas others were fully vaccinated as 3 + 1) infected with Streptococcus pneumoniae Serotype 19A in last 4 y (2015–2018).

KEYWORDS:

• Pediatric
• invasive pneumococcal disease
• serotype 19A

To the Editors,

We read the article by Gonullu et al.,¹ regarding Impact of the 13-valent Pneumococcal Conjugate Vaccine on the Incidences of Community-Acquired Pneumonia and Pneumonia-Related Hospitalizations in Children with great interest. In this article, it was stated that a significant reductions in the incidences of CAP and CAP-related hospitalization in children ≤5 y-old after the implementation of PCV13 into the NIP of Turkey. The incidence of CAP decreased from 5448 to 1144/100,000 from 2011 to 2017 (p = .001, r = −0.965). CAP incidence was found to be 22% lower when the mean annual incidence of CAP between the transition period of PCV13 (2011/2012) was compared with a postPCV13 period (2016/2017). Also, the incidence of CAP-related hospitalization decreased significantly from 943 to 335/100,000 from 2011 to 2017 (p = .004 r = −0.91). Moreover, the mean incidence of CAP hospitalization declined 35% (p = .01) between the transition period of PCV13 and a post-PCV13 period. PCV-13 has implemented incidence of CAP undoubtedly in a very good way but continuous surveillance for vaccine failures is still very important for future vaccination programs. To support this opinion we report seven children (age of the seven patients ranged between 10 months and 5 y, 10 months old patients were vaccinated 3 times with PCV13 whereas others were fully vaccinated as 3 + 1) infected with Streptococcus pneumoniae Serotype 19A in last 4 y (2015–2018). Of these patients, six had ampyema and one had meningitis, all were vaccinated according to national immunization program (NIP). Also, in the study by Moraga-Llopet al.² among the 84 patients, 3 were aged 3 to 6 months, 32 were aged 7 to 23 months and 49 were aged 24 to 59 months, serotype 19A was responsible for 2 empyema cases representing vaccine failures. In one multicenter study,³ most of the pneumococcal vaccine failures were caused by serotype 19A (the more prevalent circulating serotype) and most of these infections occurred in the first 6 months of life (and only 3of 16 vaccine failure patients were older than 5 y old), but none of the patients had received 4 PCV13 doses and only one had received 3 doses, yet it was an early evaluation just 1 y after the introduction of PCV13.

According to our opinion vaccine failure cannot be directly linked to age, it could change according to geography, vaccination coverage and percentage of the sensitive population such as immigrants and refugees.

Most studies on IPD regarding the effectiveness of PCV13 have demonstrated that PCV13 introduction has significantly reduced the incidence of IPD in both vaccinated children and unvaccinated population. Multicenter surveillance is important to view changing seroepidemiology in special circumstances such as alteration of NIP (shift to 2 + 1 with PCV13, change to PCV10, increase in vaccine hesitancy, etc.).