Unravelling the Impact of Pneumococcal Conjugate Vaccines on Ambulatory Antibiotic Drug Consumption in Young Children: An Interrupted Time Series Analysis

Impact of SARS-CoV-2 Vaccine Rollout on Hispanic and Non-Hispanic Admission and Mortality Trends: An Interrupted Time Series Analysis

BACKGROUND

Challenges with SARS-CoV-2 vaccine prioritization, access, and hesitancy have influenced vaccination uptake.

RESEARCH QUESTION

Was the impact of SARS-CoV-2 vaccine rollout on COVID-19 monthly admission and mortality trends different between Hispanic and non-Hispanic populations?

STUDY DESIGN AND METHODS

We used interrupted time series analysis to conduct an ancillary study of the Viral Infection and Respiratory Illness Universal Study registry supplemented by electronic health record data from five participating Mayo Clinic sites in Florida, Arizona, Minnesota, and Wisconsin. We included hospitalized patients with COVID-19 admitted between April 2020 and December 2021. Our primary outcome was the impact of vaccine rollout on admission trends. Our secondary outcome was the impact of vaccine rollout on mortality trends.

RESULTS

This interrupted time series analysis includes 6,442 patients. Vaccine rollout was associated with improved monthly hospital admission trends among both Hispanic and non-Hispanic patients. Among Hispanic patients, pre-vaccine rollout, monthly admissions increased by 12.9% (95% CI, 8.1%-17.9%). Immediately after vaccine rollout, patient admissions declined by -66.3% (95% CI, -75.6% to -53.9%). Post-vaccine rollout, monthly admissions increased by 3.7% (95% CI, 0.2%-7.3%). Among non-Hispanic patients, pre-vaccine rollout, monthly admissions increased by 35.8% (95% CI, 33.4%-38.1%). Immediately after vaccine rollout, patient admissions declined by -75.2% (95% CI, -77.6% to -72.7%). Post-vaccine rollout, monthly admissions increased by 5.6% (95% CI, 4.5%-6.7%). These pre-vaccine rollout admission trends were significantly different (P < .001). Post-vaccine rollout, the change in admission trend was significantly different (P < .001). The associated beneficial impact from vaccine rollout on monthly hospital admission trends among Hispanic patients was significantly lower. The trend in monthly mortality rate was fourfold greater (worse) among Hispanic patients (8.3%; 95% CI, 3.6%-13.4%) vs non-Hispanic patients (2.2%; 95% CI, 0.6%-3.8%), but this was not shown to be related to vaccine rollout.

INTERPRETATION

SARS-CoV-2 vaccine rollout was associated with improved COVID-19 admission trends among non-Hispanic vs Hispanic patients. Vaccine rollout was not shown to influence mortality trends in either group, which were four times higher among Hispanic patients. Improved vaccine rollout may have reduced disparities in admission trends for Hispanic patients, but other factors influenced their mortality trends.

Dynamics of Pediatric Antibiotic Use Differ between High- and Low-Prescribing Clinics after Pneumococcal Conjugate Vaccines

OBJECTIVE

To compare dispensed oral antibiotic prescription rates (DAPRs) after implementation of pneumococcal conjugate vaccine (PCV) in high antibiotic-prescribing clinics (HPC) with low antibiotic-prescribing clinics (LPC) in 2 distinct ethnic groups of children (Jewish and Bedouin children) <5 years of age.

METHODS

Clinics with ≥50 insured children, active both pre-PCV (2005-2009) and post-PCV (2010-2018) implementation, were included. HPC and LPC were defined by DAPRs above or below the median in each age and ethnic group. Monthly dispensed antibiotic prescription rate (DAPR) trends (adjusted for age and ethnicity) were calculated using interrupted time series. Mean yearly incidence rate-ratios (late PCV13 vs pre-PCV) were calculated.

RESULTS

Bedouin HPC had the highest pre-PCV overall-DAPR per 1000 child-years ± SD (2520.4 ± 121.2), followed by Jewish HPC (1885.5 ± 47.6), Bedouin LPC (1314.8 ± 81.6), and Jewish LPC (996.0 ± 19.6). Shortly after PCV implementation, all DAPRs and amoxicillin/amoxicillin-clavulanate DAPRs declined in all groups except Jewish LPC, stabilizing within 4-5 years post-PCV. The rates and magnitudes of declines were directly proportional to the pre-PCV DAPR magnitudes, achieving near-complete closure of the pre-PCV DAPR gaps between the 4 groups (rates during late-PCV13 ranging from 1649.4 ± 23.5 [Bedouin HPC] to 1200.3 ± 72.4 [Jewish LPC]).

CONCLUSIONS

PCVs are a powerful tool in reducing outpatient antibiotic consumption among young children, especially in HPC, resulting in partial closure of DAPR gap between HPC and LPC. The higher impact on HPC suggests that PCV-associated declines of respiratory disease may strongly contribute to a judicious antibiotic approach in clinics with high antibiotic consumption.

The impact of pneumococcal conjugate vaccine on ceftriaxone consumption in the community among young children

OBJECTIVES

Following pneumococcal conjugate vaccine (PCV) introduction, community pediatric dispensed prescription rates (DPR) of oral antibiotics declined, in parallel to respiratory tract infection (RTI). We assessed the dynamics of outpatient parenteral ceftriaxone DPR.

METHODS

Computerized data for children <5 years were examined during 13 years (including 4 pre-PCV years). DPR from clinics with ≥50 insured children, active both before and after PCV implementation were included. Interrupted time series with segmented regression stratified by age and ethnicity, and adjusted for seasonality was applied to show monthly DPR trends.

RESULTS

A total of 29,226 prescriptions were dispensed. No significant trends in ceftriaxone DPR were seen pre-PCV. Shortly after PCV implementation, DPR abruptly and significantly declined, stabilizing in late-PCV period (5 years postimplementation). The dynamics were compared between the two ethnic groups in the region, Jewish and Bedouin children (the latter with higher crowding and respiratory disease rates). Among Jewish children, ceftriaxone was mainly dispensed during winter vs no seasonality among Bedouin children.

CONCLUSIONS

In southern Israel, outpatient ceftriaxone DPR declined post-PCV in young children, similar to the trends of RTIs and oral antibiotic prescriptions, suggesting a causative role of PCVs. The differences between the two ethnic groups suggest possible involvement of additional factors.

The effect of a comprehensive typhoid conjugate vaccine campaign on antimicrobial prescribing in children in Harare, Zimbabwe: a mixed methods study

BACKGROUND

Vaccines prevent infections and could subsequently reduce antimicrobial use. A 1-week mass vaccination campaign was done with Typbar-TCV (Bharat Biotech, Hyderabad, India) between Feb 25 and March 4, 2019. We investigated whether this typhoid conjugate vaccine campaign could affect antimicrobial prescribing in children presenting to primary care in Harare, Zimbabwe.

METHODS

In this mixed methods study, data for acute paediatric outpatient consultations between Jan 1, 2018, and March 31, 2020, were collected from five clinics in Harare. Interrupted time series analysis was done to compare prescription data before and after the campaign. To contextualise findings, qualitative data were collected between April 20, 2021, and July 20, 2022, comprising ethnographic research (ie, workshops, surveys, observations, and interviews) in 14 clinics. Ethnographic data were used for thematic analysis. The primary outcome was monthly antimicrobial prescriptions in children aged 6 months to 15 years, normalised by the number of trauma events in all age groups.

FINDINGS

In the data collection period, 27 107 paediatric consultations were recorded. 17 951 (66·2%) of 27 107 children were prescribed antimicrobials. Despite the perceived reduction in typhoid cases and a decreasing trend in the prescription of antimicrobials commonly used to treat typhoid (ie, ciprofloxacin and azithromycin), mass vaccination with Typbar-TCV did not affect the total rate of antimicrobials (adjusted rate ratio, 1·20, 95% CI 0·70-2·05, p=0·51) or the rate of typhoid antimicrobials prescribed (0·93, 0·44-1·96, p=0·85). Unsafe water sources and insufficient diagnostic services were reported to contribute to the continued disease burden and antimicrobial prescription.

INTERPRETATION

Non-specific febrile illness caused by confirmed or suspected typhoid is a common cause of antimicrobial use in endemic areas. Although effective in preventing typhoid fever, we were unable to identify any effect of Typbar-TCV on antimicrobial prescribing. Ethnographic research showed the effect of contextual factors on antimicrobial prescribing, including concerns regarding safe water access, appropriate sewage disposal, health-care and diagnostic availability. To realise effects beyond disease burden reduction, holistic approaches addressing these concerns are needed so that the value of vaccines mitigating the effects of antimicrobial use as a driver of antimicrobial resistance is fully achieved.

FUNDING

Wellcome Trust.

TRANSLATION

For the Shona translation of the abstract see Supplementary Materials section.

The COVID-19 pandemic as an opportunity for unravelling the causative association between respiratory viruses and pneumococcus-associated disease in young children: a prospective study

BACKGROUND

In young children, rates of lower respiratory infections (LRI) and invasive pneumococcal disease (IPD) have been associated with respiratory syncytial virus (RSV), human metapneumovirus (hMPV), influenza (flu), and parainfluenza (PIV) (collectively termed here as pneumonia and pneumococcal disease-associated viruses [PDA-viruses]). However, their contribution to the pathogenesis of these disease endpoints has not yet been elucidated. The COVID-19 pandemic provided a unique opportunity to examine the question.

METHODS

This prospective study comprised all children <5 years, living in southern Israel, during 2016 through 2021. The data were previously collected in multiple ongoing prospective surveillance programs and include: hospital visits for community-acquired alveolar pneumonia (CAAP), non-CAAP LRI; nasopharyngeal pneumococcal carriage (<3 years of age); respiratory virus activity; and nationwide, all-ages COVID-19 episodes and IPD in children <5 years. A hierarchical statistical model was developed to estimate the proportion of the different clinical endpoints attributable to each virus from monthly time series data, stratified by age and ethnicity. A separate model was fit for each endpoint, with covariates that included a linear time trend, 12-month harmonic variables to capture unexplained seasonal variations, and the proportion of tests positive for each virus in that month.

FINDINGS

During 2016 through 2021, 3,204, 26,695, 257, and 619 episodes of CAAP, non-CAAP LRI, pneumococcal bacteremic pneumonia and non-pneumonia IPD, respectively, were reported. Compared to 2016-2019, broad declines in the disease endpoints were observed shortly after the pandemic surge, coincident with a complete disappearance of all PDA-viruses and continued circulation of rhinovirus (RhV) and adenovirus (AdV). From April 2021, off-season and abrupt surges of all disease endpoints occurred, associated with similar dynamics among the PDA-viruses, which re-emerged sequentially. Using our model fit to the entire 2016-2021 period, 82% (95% CI, 75-88%) of CAAP episodes in 2021 were attributable to the common respiratory viruses, as were 22%-31% of the other disease endpoints. Virus-specific contributions to CAAP were: RSV, 49% (95% CI, 43-55%); hMPV, 13% (10-17%); PIV, 11% (7-15%); flu, 7% (1-13%). RhV and AdV did not contribute. RSV was the main contributor in all endpoints, especially in infants. Pneumococcal carriage prevalence remained largely stable throughout the study.

INTERPRETATION

RSV and hMPV play a critical role in the burden of CAAP and pneumococcal disease in children. Interventions targeting these viruses could have a secondary effect on the burden of disease typically attributed to bacteria.

FUNDING

There was no funding for this study.

Remote Versus In-person Outpatient Clinic Visits and Antibiotic Use Among Children During the COVID-19 Pandemic

BACKGROUND

The proportion of remote clinic visits was expected to increase among children during the COVID-19 pandemic which might result in antibiotic overuse.

METHODS

In southern Israel, 2 ethnic groups, Jewish and Bedouin, live side-by-side. Computerized data on visits for children <18 years were examined from clinics with ≥50 insured children, active both pre-COVID-19 and during the COVID-19 pandemic. Visits were divided into in-person and remote. Monthly infectious diagnoses and dispensed antibiotic prescription rates were calculated by age (<5, 5-17 years) and ethnic groups. Mean monthly rates of 2 parallel seasons (pre-COVID-19 and COVID-19 periods) were compared.

RESULTS

Overall 2,120,253 outpatient clinic visits were recorded. Remote clinic visit rates (per 1000 children) increased from 97.04 and 33.86 in the pre-COVID-19 to 179.75 and 50.05 in the COVID-19 period in Jewish and Bedouin children, respectively ( P < 0.01) along with a reduction of in-person visit rates in both populations. Comparing pre-COVID-19 and COVID-19 periods, the rates of overall infectious diagnoses in remote visits increased. Nevertheless, dispensed antibiotic prescription rates in remote visits (per 1000 visits) remained unchanged (9.84 vs. 8.67, P = 0.70, in the Jewish population and 14.32 vs. 14.17, P = 1.00, in the Bedouin population in the pre-COVID-19 and COVID-19 periods, respectively) with a similar distribution of antibiotic categories.

CONCLUSIONS

COVID-19 pandemic resulted in an expansion of remote visits of children <18 years with an increase in infectious diagnoses. However, remote dispensed antibiotic prescription rates remained unchanged. These dynamics were more accentuated in Jewish children, characterized by higher socio-economic conditions, compared to Bedouin children.

Disproportionate reduction in respiratory vs. non-respiratory outpatient clinic visits and antibiotic use in children during the COVID-19 pandemic

Background

The COVID-19 pandemic led to improved hygiene and reduced social encounters. Near elimination of the activity of respiratory syncytial virus and influenza viruses were observed, worldwide. Therefore, we assessed the rates of pediatric outpatient clinic visits and medications prescribed at those visits during the coronavirus disease 2019 (COVID-19) pandemic and pre-COVID-19 period (2016–2019).

Methods

Monthly and annual incidence rates for respiratory and non-respiratory diagnoses and dispensed prescription rates were calculated. Acute gastroenteritis (AGE) visits were analyzed separately since the mode of transmission is influenced by hygiene and social distancing.

Results

Overall, 5,588,702 visits were recorded. Respiratory and AGE visits declined by 49.9% and 47.3% comparing the COVID-19 and pre-COVID-19 periods. The respective rate reductions for urinary tract infections, trauma, and skin and soft tissue infections were 18.2%, 19.9%, and 21.8%. Epilepsy visits increased by 8.2%. Overall visits rates declined by 21.6%. Dispensed prescription rates of antibiotics and non-antibiotics respiratory medications declined by 49.3% and 44.4%, respectively. The respective declines for non-respiratory antibiotics and non-antibiotics were 15.1% and 0.2%. Clinic visits and prescription rates reductions were highest in April–May, following the first lockdown in Israel.

Conclusions

COVID-19 pandemic resulted in a substantial reduction in respiratory outpatient clinic visits and dispensed respiratory drugs, with only a mild reduction seen for non-respiratory visits. These trends were probably driven by COVID-19 mitigation measures and by the profound disruption to non-SARS COV-2 respiratory virus activity.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-022-03315-0.

PCV13 Vaccination of Adults against Pneumococcal Disease: What We Have Learned from the Community-Acquired Pneumonia Immunization Trial in Adults (CAPiTA)

The Community-Acquired Pneumonia immunization Trial in Adults (CAPiTA) evaluated older adult pneumococcal vaccination and was one of the largest vaccine clinical trials ever conducted. Among older adults aged ≥65 years, the trial established 13-valent pneumococcal conjugate vaccine (PCV13) efficacy in preventing first episodes of bacteremic and nonbacteremic pneumococcal vaccine serotype (VT) community acquired pneumonia (CAP), and of vaccine serotype invasive pneumococcal disease (VT-IPD). Since the publication of the original trial results, 15 additional publications have extended the analyses. In this review, we summarize and integrate the full body of evidence generated by these studies, contextualize the results in light of their public health relevance, and discuss their implications for the assessment of current and future adult pneumococcal vaccination. This accumulating evidence has helped to better understand PCV13 efficacy, serotype-specific efficacy, efficacy in subgroups, the interpretation of immunogenicity data, and the public health value of adult PCV vaccination.