[Pneumococcal vaccination coverage in at-risk children in Catalonia]

Evaluating clinical effectiveness and impact of anti-pneumococcal vaccination in adults after universal childhood PCV13 implementation in Catalonia, 2017-2018

Background

At present, because of indirect effects derived from routine childhood immunisation, clinical benefits vaccinating adults with the 23-valent pneumococcal polysaccharide vaccine (PPsV23) and/or the 13-valent pneumococcal conjugate vaccine (PCV13) are uncertain. This study investigated clinical effectiveness for both PPsV23/PCV13 in preventing pneumonia among Catalonian adults during an earlier 2-year period post-PCV13 free (publicly funded) approval for infants.

Methods

We conducted a Population-based cohort study involving 2,059,645 adults ≥ 50 years in Catalonia, Spain, who were followed between 01/01/2017-31/12/2018. Primary outcomes were hospitalisation from pneumococcal pneumonia (PP) or all-cause pneumonia (ACP) and main explanatory variable was PCV13/PPsV23 vaccination status. Cox regression models were used to estimate vaccination effectiveness adjusted by age/sex and underlying-risk conditions.

Results

Cohort members were followed for 3,958,528 person-years (32,328 PCV13-vaccinated, 1,532,186 PPsV23-vaccinated), observing 3592 PP (131 in PCV13-vaccinated vs 2476 in PPsV23-vaccinated) and 24,136 ACP (876 in PCV13-vaccinated vs 17,550 in PPsV23-vaccinated). Incidence rates (per 100,000 person-years) were 90.7 for PP (394.2 in PCV13-vaccinated vs 161.6 in PPsV23-vaccinated) and 609.7 for ACP (2636.3 in PCV13-vaccinated vs 1145.4 in PPsV23-vaccinated). The PCV13 was associated with an increased risk of PP (hazard ratio [HR]: 1.24; 95% CI: 1.00-1.52; p = 0.046) and ACP (HR: 1.38; 95% CI: 1.28-1.49; p < 0.001) whereas the PPsV23 did not alter the risk of PP (HR: 1.07; 95% CI: 0.98-1.18; p = 0.153) and slightly increased the risk of ACP (HR: 1.14; 95% CI: 1.10-1.18; p < 0.001). In supplementary analyses focused on at-risk individuals (i.e., elderly persons, immunocompromissing and other chronic illnesses) protective effects of vaccination did not emerge either.

Conclusions

Data does not support clinical benefits from pneumococcal vaccination (nor PCV13 neither PPsV23) against pneumonia among Catalonian middle-aged and older adults in the current era of universal PCV13 childhood immunisation in our setting. New extended valency PCVs are greatly needed.

Evaluating clinical effectiveness of 13-valent pneumococcal conjugate vaccination against pneumonia among middle-aged and older adults in Catalonia: results from the EPIVAC cohort study

Background

Benefits using the 13-valent pneumococcal conjugate vaccine (PCV13) in adults are controversial. This study investigated clinical effectiveness of PCV13 vaccination in preventing hospitalisation from pneumonia among middle-aged and older adults.

Methods

Population-based cohort study involving 2,025,730 individuals ≥50 years in Catalonia, Spain, who were prospectively followed from 01/01/2015 to 31/12/2015. Primary outcomes were hospitalisation for pneumococcal or all-cause pneumonia and death from any cause. Cox regression models were used to evaluate the association between PCV13 vaccination and the risk of each outcome, adjusting for age, sex and major comorbidities/underlying risk conditions.

Results

Cohort members were observed for a total of 1,990,701 person-years, of which 6912 person-years were PCV13 vaccinated. Overall, crude incidence rates (per 100,000 person-years) were 82.8 (95% confidence interval [CI]: 77.7–88.1) for pneumococcal pneumonia, 637.9 (95% CI: 599.0–678.7) for all-cause pneumonia and 2367.2 (95% CI: 2222.8–2518.7) for all-cause death. After multivariable adjustments we found that the PCV13 vaccination did not alter significantly the risk of pneumococcal pneumonia (multivariable-adjusted hazard ratio [mHR]: 1.17; 95% CI: 0.75–1.83; p = 0.493) and all-cause death (mHR: 1.07; 95% CI: 0.97–1.18; p = 0.190), although it remained significantly associated with an increased risk of all-cause pneumonia (mHR: 1.69; 95% CI: 1.48–1.94; p < 0.001). In stratified analyses focused on middle-aged or elderly persons and immunocompromised or immunocompetent subjects, PCV13 vaccination did not appear effective either.

Conclusion

Our data does not support clinical benefits of PCV13 vaccination against pneumonia among adults in Catalonia. It must be closely monitored in future studies involving more vaccinated person-time at-observation.

Pneumococcal vaccination coverages among low-, intermediate-, and high-risk adults in Catalonia

There is scarce data about pneumococcal vaccination coverages among adults in recent years. We investigated current pneumococcal vaccination coverages in Catalonia, Spain, with a cross-sectional population-based study including 2,033,465 individuals aged 50 y or older assigned to the Catalonian Health Institute at 01/01/2015 (date of survey). A previously validated institutional research clinical Database was used to classify study subjects by their vaccination status for both 23-valent pneumococcal polysaccharide vaccine (PPSV23) and 13-valent pneumococcal conjugate vaccine (PCV13), to identify comorbidities and underlying conditions, and establish the risk stratum of each individual: High risk stratum: functional or anatomic asplenia, cochlear implants, CSF leaks, or immunocompromising conditions; medium risk stratum: immunocompetent persons with history of chronic cardiac or respiratory disease, liver disease, diabetes mellitus, alcoholism and/or smoking; low risk stratum: persons without high or medium risk conditions. Of the total 2,033,465 study population, an amount of 789,098 (38.8%) had received PPVS23, whereas 5031 (0.2%) had received PCV13. PPSV23 coverages increased largely with increasing age: 4.8% in 50-59 y vs 35.5% in 60-69 y vs 71.9% in 70-79 y vs 79.5% in 80 y or older; p < 0.001). PCV13 coverages also increased with age, although they were very low in all age groups. PPSV23 coverages were 59.2% in high risk stratum, 48.3% in medium risk stratum and 28.1% in low risk stratum (p < 0.001). For the PCV13, uptakes were 1.2%, 0.3% and 0.1% in high, medium and low stratum, respectively (p < 0.001). In conclusion, pneumococcal vaccination coverages in Catalonian adults are not optimal, being especially small for the PCV13 (even in high-risk subjects).