Background

The cost-effectiveness studies of adult pneumococcal vaccinations have shown discordant results. We evaluated the cost-effectiveness of pneumococcal vaccinations for high-risk groups in 18–84-year-olds under the PCV13 childhood vaccination programme.

Methods

A multi-cohort model with 15 year time-horizon was applied to estimate the cost-effectiveness of PCV13 and PPV23 vaccinations for various age and risk groups. Risk groups (diabetes, asthma or chronic obstructive pulmonary disease (COPD), renal failure or chronic heart failure) were defined using the Register for Special Reimbursements of medical expenses. The pneumococcal disease incidence in the risk groups were estimated by linking individual’s events within and between individual-level national registries.

Results

The disease incidence was highest among the renal failure risk group and both PCV13 and PPV23 vaccinations were cost-saving in 18–74-year-olds. In ≥65-year-olds PPV23 vaccinations were more cost-effective than PCV13 vaccinations. In all risk groups both vaccinations were most cost-effective in 65–74-year-olds. The results were sensitive to the changes in effectiveness and price of both vaccines and assumed mortality impact of vaccinations and life expectancy estimates.

Conclusions

Life expectancy affects significantly the cost-effectiveness results among the elderly. When evaluating the cost-effectiveness of pneumococcal risk group vaccinations it’s important to consider the high all-cause mortality among the elderly at-risk population.

Background

Respiratory infections are the most common cause of antimicrobial prescriptions in children. We have earlier reported 18% reduction in antimicrobial use. Now, we evaluated the long-term impact of PCV10 introduction into the Finnish NVP on antimicrobial use in vaccine-eligible children.

Methods

PCV10-NVP began 09/2010 (2+1 schedule) with high uptake at 92-95%. The target cohort eligible for NVP (children born 06/2010-09/2016) was compared with calendar-time and age-matched (3-78 months) reference cohort before NVP introduction (Figure) 3-6 years after PCV introduction. Purchase data were collected from the Social Insurance Institution of Finland reimbursement register. We assessed the trends in outpatient purchases of antimicrobials recommended for treatment of acute otitis media in the national guidelines (amoxicillin with/without enzyme inhibitor, cefuroxime, cefaclor, clarithromycin, azithromycin) but complete data on penicillin, and sulfadiazine/trimethoprim were not available.

Results

Rates of antimicrobial purchases were 0.93 and 0.66 per person-year in the reference and target cohorts, respectively. The relative and absolute rate reductions were 29.1% (95%CI 28.8-29.3) and 0.27 per person-year, respectively.

Conclusions

Continuous reduction in antimicrobial use observed since PCV introduction is compatible with the development of indirect effects. Although the decline started soon after PCV introduction, other reasons may also have contributed to the decline.

Background

Following introduction of 10-valent pneumococcal conjugate vaccine (PCV10) into Finnish infant vaccination program in 2010, serotype 19A invasive pneumococcal disease (IPD) increased particularly among older adults. We studied changes in genomic epidemiology and antimicrobial resistance of 19A-IPD isolates among elderly and children.

Methods

All 19A-IPD isolates from adults ≥65 years and children <5 years sent routinely to the national reference laboratory before (2007–2008) and after (2013–2015) PCV10-introduction were analyzed. Antimicrobial susceptibility was determined by agar dilution method using EUCAST breakpoints. Multilocus sequence typing profiles were derived from whole-genome sequencing data using Ridom SeqSphere+.

Results

Before PCV10-introduction, the most prevalent 19A clones were ST482 (antimicrobial susceptible) and ST193 (resistant to erythromycin, clindamycin, and tetracycline). During PCV10-period, antimicrobial susceptible ST199 and ST994 predominated among elderly, whereas ST994 and ST671-SLV (non-susceptible to penicillin and resistant to erythromycin) dominated among children. No increase in multidrug-resistant ST320 or ST230 was detected.

Conclusions

The genomic structure of 19A IPD isolates of elderly patients changed after infant PCV10-introduction. Although the changes resembled those observed in children, the most prevalent clones were not entirely the same in both age groups. Besides infant vaccination, also other factors like antimicrobial resistance or comorbidities/other predisposing factors in older adults may explain these differences.

Background

Limited data are available on the population impact of mature PCV10 programs. We evaluated long-term changes in IPD incidence and serotypes.

Methods

Culture-confirmed IPD cases (n=9481) were identified through national, population-based laboratory surveillance; person-years of follow-up were obtained from population registry. We compared IPD rates before (7/2004-6/2010) and after (7/2011-6/2018) PCV10 introduction.

Results

IPD incidence in children <5 years decreased from 37 to 10/100,000 person-years; no PCV10 type cases were seen in 2018. Before PCV10 introduction, overall IPD incidence was increasing (p for trend <0.05; Figure). IPD rates overall and in persons >65 years were similar before and after PCV10 (Table). Non-vaccine serotypes (NVT) increased in all age groups, particularly the elderly. Serotype 19A was most common NVT in children. In adults, serotypes 3, 19A, 22F and 6C accounted for most of the NVT rate increase.

Figure: IPD incidence by serotype group from 7/2004 to 6/2018, all ages

Conclusions

After 8 years of infant PCV10 program, IPD incidence has reached a steady state with substantial reductions in children and leveling of NVT increase in adults. Herd effects also seem to have offset the pre-vaccine increase in adult IPD incidence and similar overall disease burden remains.