Effectiveness of 13-Valent Pneumococcal Conjugate Vaccine on Radiological Primary Endpoint Pneumonia Among Cases of Severe Community Acquired Pneumonia in Children in Northern India: A Multi-Site Hospital-Based Study

Abstract

Background: Streptococcus pneumoniae is the leading bacterial cause of community acquired pneumonia (CAP) in children and produces primary end point pneumonia with or without infiltrates (PEP±I) in chest x-rays (CXRs). Pneumococcal Conjugate Vaccination 13 (PCV13) has been introduced in the national immunization program in India since 2017. Our aim was to compare the PEP±I on CXR in children hospitalized with WHO-defined severe CAP among those who had received ≥ 2 doses of PCV13 (exposed) versus unexposed. Methods: Prospective hospital-based pneumonia surveillance data analysis of three districts of Northern India which had introduced PCV in 2017/2018. Included were children aged 2-23 months, hospitalized with severe CAP, with interpretable CXR, after parental consent. Clinical data was abstracted from hospital records and exposure to PCV from immunization card. CXR were interpreted by a panel of three independent blinded radiologists. Findings: From May 2017-March 2020, 2658 subjects were included, of which 586 (22·0%) exposed to PCV13. PEP±I was found 555 (20·9%), of which 94 (16·9%) exposed. Crude vaccine effectiveness was 33·0% (95% CI, 15·0 to 48·0). In conditional logistic regression, adjusted odds ratio (OR) for PEP±I with exposure was 0·74 (95% CI, 0·58 to 0·95). Crude OR of hospital mortality in those with PEP±I was 3·86 (95% CI, 1·83 to 8·15, p<0·001). Interpretation: In severe CAP, vaccination with < 2 doses of PCV13 had statistically significantly reduced odds of having PEP±I. Since the latter had increased odds of hospital mortality due to CAP, country wide coverage with PCV13 is essential on priority. Funding: BMGF Grant No:OPP1189869/INV-006521 KGMU. Declaration of Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. Ethics Approval Statement: The protocol was approved by the Ethics Review Committee of King George’s Medical University (Lucknow), Patna Medical College and Hospital (Patna) and Darbhanga Medical College and Hospital (Darbhanga). The caregivers/ guardians of children signed the written, informed consent for participation in the study.