Related Experiment Video
Updated: Jun 14, 2026

Experimental Human Pneumococcal Carriage
Published on: February 15, 2013
Comment on Chandler et al. 23-Valent Pneumococcal Polysaccharide Vaccination Does Not Prevent Community-Acquired
Nicole Cossrow1, Rennie Joshi1, Kenneth Klinker1
1Merck & Co., Inc., Rahway, NJ 07065, USA.
Abstract:
The 23-valent pneumococcal polysaccharide vaccine (PPSV23) targets 23 common serotypes and is recommended for use in adults in various countries to protect against pneumococcal infection. Test-negative design (TND) studies aim to include cases and controls from the same healthcare facilities; however, design choices or limitations associated with conducting real-world research can affect the study results. Here, we highlight how some methodological limitations may have affected results and conclusions of a published study described by Chandler et al.
Related Concept Videos
Pneumonia I: Introduction
Risk Factors
Various factors influence the likelihood of developing pneumonia. Age plays a crucial role, with infants, children under two, and individuals over 65 at increased risk due to their...
Pneumonia II: Pathophysiology
Pneumonia IV: Management
Bacterial Pneumonia Treatment
For bacterial pneumonia, antibiotics serve as the cornerstone of therapy. Initial treatment often begins with empirical antibiotics, tailored to the anticipated causative organism and adjusted based on culture results. Key antibiotic choices include:
Pneumonia V: Nursing management and Prevention
The nurse must practice strict medical asepsis and adhere to infection control guidelines to minimize healthcare-associated infections.
Enhance airway patency
Position the patient correctly to facilitate drainage of the affected lung segments. Manual or mechanical percussion and vibration can also be employed.
Streptococcal Pharyngitis
Pneumonia I: Introduction

