Hong-Yi Lee1, Yu-Chia Hsieh2, Ching-Chuan Liu3, Yi-Chuan Huang4, Kuang-Yi Chang5, Hsin Chi6, Luan-Yin Chang7, Yhu-Chering Huang8, Li-Min Huang7. 1. Department of Pediatrics, Chang Gung Children's Hospital, Chang Gung Memorial Hospital, Taoyuan, Taiwan. 2. Department of Pediatrics, Chang Gung Children's Hospital, Chang Gung Memorial Hospital, Taoyuan, Taiwan; Chang Gung University, College of Medicine, Taoyuan, Taiwan. Electronic address: yuchiahsieh@gmail.com. 3. Department of Pediatrics, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan. 4. Department of Pediatrics, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan. 5. Division of Biostatistics, Graduate Institute of Epidemiology and Preventive Medicine, National Taiwan University, Taipei, Taiwan; Department of Anesthesiology, Taipei Veterans General Hospital and National Yang-Ming University School of Medicine, Taipei, Taiwan. 6. Department of Pediatrics, Mackay Memorial Hospital, Taipei, Taiwan. 7. Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan. 8. Department of Pediatrics, Chang Gung Children's Hospital, Chang Gung Memorial Hospital, Taoyuan, Taiwan; Chang Gung University, College of Medicine, Taoyuan, Taiwan.
Abstract
BACKGROUND: In Taiwan, the age group with the greatest incidence of invasive pneumococcal disease is 2-5 years of age, which is different from other countries. This study was conducted to identify risk factors and different 13-valent pneumococcal conjugate vaccine (PCV13) schedules associated with vaccine-type invasive pneumococcal pneumonia (IPP) despite prior vaccination. METHODS: A case-control study was conducted prospectively between August 2012 and December 2015 at five participating medical centers. The study enrolled children <15 years of age who were admitted to one of the five medical centers for CAP. Blood samples and acute-phase serum specimens were collected and Streptococcus pneumoniae was identified by using a real-time polymerase-chain-reaction (RT-PCR) assay targeting the lytA gene. RESULTS: A total of 25 children diagnosed with vaccine-type IPP and 124 controls were enrolled. Vaccine-type IPP occurred in 6 (28.6%), 14 (24.1%), and 5 (7.1%) children receiving vaccines on a not-age-appropriate schedule (n = 21), primary infant schedule (n = 58), and toddler catch-up schedule (n = 70) (P = 0.008), respectively. Of 25 children, the mean age at disease onset was 36 ± 11 months; serotype 19A was responsible for 84% (21/25). CONCLUSION: After adjustment for confounding factors, the risk of vaccine-type IPP was significantly higher among children receiving vaccines on a not-age-appropriate schedule, or on a primary infant schedule, compared with children receiving vaccines on a toddler catch-up schedule. Duration of vaccine immunity should be investigated to direct strategies for maintaining individual and population immunity against pneumococcal disease.
BACKGROUND: In Taiwan, the age group with the greatest incidence of invasive pneumococcal disease is 2-5 years of age, which is different from other countries. This study was conducted to identify risk factors and different 13-valent pneumococcal conjugate vaccine (PCV13) schedules associated with vaccine-type invasive pneumococcal pneumonia (IPP) despite prior vaccination. METHODS: A case-control study was conducted prospectively between August 2012 and December 2015 at five participating medical centers. The study enrolled children <15 years of age who were admitted to one of the five medical centers for CAP. Blood samples and acute-phase serum specimens were collected and Streptococcus pneumoniae was identified by using a real-time polymerase-chain-reaction (RT-PCR) assay targeting the lytA gene. RESULTS: A total of 25 children diagnosed with vaccine-type IPP and 124 controls were enrolled. Vaccine-type IPP occurred in 6 (28.6%), 14 (24.1%), and 5 (7.1%) children receiving vaccines on a not-age-appropriate schedule (n = 21), primary infant schedule (n = 58), and toddler catch-up schedule (n = 70) (P = 0.008), respectively. Of 25 children, the mean age at disease onset was 36 ± 11 months; serotype 19A was responsible for 84% (21/25). CONCLUSION: After adjustment for confounding factors, the risk of vaccine-type IPP was significantly higher among children receiving vaccines on a not-age-appropriate schedule, or on a primary infant schedule, compared with children receiving vaccines on a toddler catch-up schedule. Duration of vaccine immunity should be investigated to direct strategies for maintaining individual and population immunity against pneumococcal disease.