Pneumococcal vaccine effect on hospitalization rates of pneumonia in children: A meta-analysis.

Zhu, Xiuling; Li, Xiaofei

INTRODUCTION Since the appearance of the pneumococcal conjugate vaccine the frequency of community-acquired pneumonia hospitalizations was decreased significantly especially in children younger than 2 years, but its effects are still conflicting. This meta-analysis study was performed to assess the relationship between the effects of different types of pneumococcal conjugate vaccines compared to each other on the frequency of community-acquired pneumonia hospitalizations in children aged less than 2 years. METHODS Through a systematic literature search up to December 2020, 20 studies were found recording relationships between the effects of different types of pneumococcal conjugate vaccines compared to each other on the frequency of community-acquired pneumonia hospitalizations in children aged less than 2 years. Odds ratio (OR) with 95% confidence intervals (CIs) was calculated between different types of pneumococcal conjugate vaccines compared to each other on the frequency of community-acquired pneumonia hospitalizations in children aged less than 2 years using the dichotomous methods with a random or fixed-effect model. RESULTS The pneumococcal conjugate vaccine 10 was significantly related to a lower hospitalization rate for pneumonia (OR, 0.64; 95% CI, 0.51-0.81, p<0.001) compared to no vaccine and (OR, 0.78; 95% CI, 0.68-0.90, p<0.001) compared to pneumococcal conjugate vaccine 7. The pneumococcal conjugate vaccine 13 was significantly related to a lower hospitalization rate for pneumonia (OR, 0.63; 95% CI, 0.56-0.71, p<0.001) compared to no vaccine and (OR, 0.56; 95% CI, 0.36-0.89, p=0.01) compared to pneumococcal conjugate vaccine 7. The pneumococcal conjugate vaccine 13 was significantly related to a lower hospitalization rate for pneumonia (OR, 0.67; 95% CI, 0.48-0.93, p=0.02) compared to pneumococcal conjugate vaccine 10. CONCLUSIONS The pneumococcal conjugate vaccines 10 or 13 may have independent relationships in reducing the frequency of community-acquired pneumonia hospitalizations in children aged less than 2 years compared to no vaccine or pneumococcal conjugate vaccines 7. Also, the pneumococcal conjugate vaccine 13 may have the same independent relationship compared to pneumococcal conjugate vaccines 10. Further studies are needed to solidify the findings to other vaccines to have evidence-based information that could help in establishing future immunization strategies.