Effects of pneumococcal vaccine in patients with chronic respiratory disease
Authors: Muungo Lungwani 
Published: June 2020

When I started my PhD with my thesis entitled ‘‘Correlation ofQuantitative CT with selective alveolobronchogram andpulmonary function tests in emphysema’’ [1], the researchperformed in our dept was mainly focused on the pathogenesisand treatment of chronic obstructive pulmonary disease(COPD). Following my PhD, my further research focused oncontrol of breathing in patients with COPD [2, 3]. Part of myscientific work is the long-term observation of patients withchronic respiratory tract infection. In particular, I haveinvestigated the antibiotic resistance according to genotype ofpenicillin-binding protein and macrolide resistance genes ofStreptococcus peumoniae and Haemophilus influenzae isolatedfrom the patients with chronic respiratory diseases. I identifiedthe relationship between the emergence of resistant genes andthe risk factors of the patients. The pneumococcal vaccineincludes 23 purified capsular antigens, which covers 95% ofSTATEMENT OF INTEREST: None declared. the penicillin-nonsusceptible serotypes, and is expected toEur Respir Rev 2008; 17: 107, 43–45DOI: 10.1183/09059180.00010717Copyright?ERSJ Ltd 2008cEUROPEAN RESPIRATORY REVIEW VOLUME 17 NUMBER 107 43reduce the incidence of drug-resistant strains [4]. I thenfocused on the usefulness of the pneumococcal vaccine inpreventing either pneumonia or death in adults with chronicrespiratory disease and reducing penicillin-nonsusceptiblestrains.The percentage of respiratory tract infections caused bypneumococcus is particularly high among elderly patients.The currently available pneumococcal vaccine stimulates theformation of specific antibodies in vivo, resulting in theprevention of pneumococcal infection; the antibody specificto pneumococci is produced within 1 month of vaccinationand is retained in vivo for ,5 yrs. Among the studiesconducted to date to evaluate the effectiveness of pneumococcalvaccines, a placebo-controlled study involving mineworkers (known to have a high incidence of pneumococcalpneumonia, i.e. several percent or higher per year) and someother groups was performed in the 1970s. The study demonstratedthe effectiveness of vaccines against pneumonia andsepsis. In developed countries, however, it is very difficult todemonstrate the effectiveness of pneumococcal vaccines withthis type of study because the incidence of pneumococcalpneumonia is very low and .20,000 subjects need to beassigned to both the vaccinated group and the control(nonvaccinated group) for evaluation of effectiveness. In recentyears, the effectiveness of pneumococcal vaccines was studiedprimarily using case–control or indirect cohort study designs,demonstrating that vaccines are not useful in preventing theonset of nonbacteraemic pneumonia, but are for pneumococcalbacteraemia [5, 6]. In Japan, the percentage of people vaccinatedagainst pneumococcal infection is very low (2%), and itis difficult to perform a case–control study involving subjectswith pneumococcal infection, as is often done in developedcountries. In our cohort study, we were able to demonstrate theusefulness of vaccination despite the relatively small size of thepopulation studied. This probably owes much to the studydesign, i.e. the adoption of bacterial respiratory infection(which often complicates chronic respiratory disease) as anindicator of the effectiveness of vaccination and the techniqueof repeated measures analysis of variance, to compare thechange in the incidence of infection from the pre-vaccination tothe post-vaccination period between the vaccinated andnonvaccinated groups (fig. 1, table 1).