Modeling geographic vaccination strategies for COVID-19 in Norway.

Vaccination was a key intervention in controlling the COVID-19 pandemic globally. In early 2021, Norway faced significant regional variations in COVID-19 incidence and prevalence, with large differences in population density, necessitating efficient vaccine allocation to reduce infections and severe outcomes. This study explored alternative vaccination strategies to minimize health outcomes (infections, hospitalizations, ICU admissions, deaths) by varying regions prioritized, extra doses prioritized, and implementation start time. Using two models (individual-based and meta-population), we simulated COVID-19 transmission during the primary vaccination period in Norway, covering the first 7 months of 2021. We investigated alternative strategies to allocate more vaccine doses to regions with a higher force of infection. We also examined the robustness of our results and highlighted potential structural differences between the two models. Our findings suggest that early vaccine prioritization could reduce COVID-19 related health outcomes by 8% to 20% compared to a baseline strategy without geographic prioritization. For minimizing infections, hospitalizations, or ICU admissions, the best strategy was to initially allocate all available vaccine doses to fewer high-risk municipalities, comprising approximately one-fourth of the population. For minimizing deaths, a moderate level of geographic prioritization, with approximately one-third of the population receiving doubled doses, gave the best outcomes by balancing the trade-off between vaccinating younger people in high-risk areas and older people in low-risk areas. The actual strategy implemented in Norway was a two-step moderate level aimed at maintaining the balance and ensuring ethical considerations and public trust. However, it did not offer significant advantages over the baseline strategy without geographic prioritization. Earlier implementation of geographic prioritization could have more effectively addressed the main wave of infections, substantially reducing the national burden of the pandemic.

Infection prevention guidelines and considerations for paediatric risk groups when reopening primary schools during COVID-19 pandemic, Norway, April 2020.

In response to the coronavirus disease (COVID-19) pandemic, most countries implemented school closures. In Norway, schools closed on 13 March 2020. The evidence of effect on disease transmission was limited, while negative consequences were evident. Before reopening, risk-assessment for paediatric risk groups was performed, concluding that most children can attend school with few conditions requiring preventative homeschooling. We here present infection prevention and control guidelines for primary schools and recommendations for paediatric risk groups.

Assessing Severity in Pediatric Pneumonia: Predictors of the Need for Major Medical Interventions.

OBJECTIVE: The aim of this study was to determine potential predictors of the need for major medical interventions in the context of assessing severity in pediatric pneumonia. METHODS: This was a prospective, cohort study of previously healthy children and adolescents younger than 18 years presenting to the pediatric emergency room with clinically suspected pneumonia and examining both the full cohort and those with radiologically confirmed pneumonia. The presence of hypoxemia (peripheral oxygen saturation ≤92%), age-specific tachypnea, high temperature (≥38.5°C), chest retraction score, modified Pediatric Early Warning Score, age, C-reactive protein, white blood cell (WBC) count, and chest radiograph findings at first assessment were analyzed by univariate and multivariate analyses to examine their predictive ability for the need for major medical interventions: supplemental oxygen, supplemental fluid, respiratory support, intensive care, or treatment for complications during admission. RESULTS: Fifty percent of the 394 cases of suspected pneumonia and 60% of the 265 cases of proven pneumonia were in need of 1 or more medical interventions. In multivariate logistic regression, only the presence of hypoxemia (odds ratios, 3.66 and 3.83 in suspected and proven pneumonia, respectively) and chest retraction score (odds ratios, 1.21 and 1.31, respectively for each 1-point increase in the score) significantly predicted the need for major medical interventions in both suspected and proven pneumonia. Specificity of 94% or greater, positive likelihood ratio of 6.4 or greater, and sensitivity of less than 40% were found for both hypoxemia and chest retraction score in predicting major medical interventions. C-reactive protein and white blood cell count were not associated with the need for these interventions, whereas multifocal radiographic changes were. CONCLUSIONS: Hypoxemia and an assessment of chest retractions were the predictors significantly able to rule in more severe pneumonia, but with a limited clinical utility given their poor ability to rule out the need for major medical interventions. Future validation of these findings is needed.

Mycoplasma Pneumoniae: A Cross-sectional Population-based Comparison of Disease Severity in Preschool and School-age Children.

BACKGROUND: Mycoplasma pneumoniae causes epidemics of upper respiratory disease and pneumonia. It is thought that M. pneumoniae usually causes milder upper respiratory disease in preschool children, with a greater chance of pneumonia in school-age children. In this population-based cross-sectional study, we present evidence that severe M. pneumoniae infection is more common in preschool children than previously thought. METHODS: During an M. pneumoniae epidemic in our area, widespread health service and public awareness lead to extensive testing for M. pneumoniae. Medical records of hospital-referred M. pneumoniae-positive children were assessed retrospectively for respiratory disease and chest radiographic results. Severe disease was defined as supplementary oxygen or fluid requirement, mechanical ventilatory support or neurologic disease. Age-specific population figures were used to calculate incidence during the study period. Those who were 0-5-year-olds were considered preschool, whereas 6-17-year-olds were considered school-aged. RESULTS: Thirty-seven preschool and 55 school-age children were referred to the hospital and tested positive for M. pneumoniae. Twenty-two (60%) preschool and 23 (42%) school-age children had severe disease [incidence 56 vs. 29 per 100,000; relative risk: 1.9; 95% confidence interval (CI): 1.06-3.4; P = 0.03]. Twenty (54%) preschool and 19 (35%) school-age children had severe pneumonia (incidence 51 vs. 24 per 100,000; relative risk: 2.1; 95% CI: 1.1-3.9; P = 0.03). CONCLUSIONS: During an M. pneumoniae epidemic in Akershus and North Oslo in 2011-2012, preschool children infected with M. pneumoniae had significantly higher risk of severe disease, particularly severe pneumonia, when compared with school-age children. M. pneumoniae should be considered a potential pathogen in younger children with respiratory distress, particularly during an epidemic period.

Clinical features and inflammatory markers in pediatric pneumonia: a prospective study.

In this prospective, observational study on previously healthy children <18 years, we aimed to study the diagnostic ability of clinical features and inflammatory markers to (i) predict pathologic chest radiography in suspected pneumonia and (ii) differentiate etiology in radiological proven pneumonia. In 394 cases of suspected pneumonia, 265 (67%) had radiographs consistent with pneumonia; 34/265 had proof of bacterial etiology. Of the cases, 86.5% had received pneumococcal conjugate vaccine. In suspected pneumonia, positive chest radiography was significantly associated with increasing C-reactive protein (CRP) values, higher age, and SpO2 ≤92% in multivariate logistic regression, OR 1.06 (95% CI 1.03 to 1.09), OR 1.09 (95% CI 1.00 to1.18), and OR 2.71 (95% CI 1.42 to 5.18), respectively. In proven pneumonia, bacterial pneumonia was significantly differentiated from viral/atypical pneumonia by increasing CRP values and SpO2 >92% in multivariate logistic regression, OR 1.09 (95% CI 1.05 to 1.14) and OR 0.23 (95% CI 0.06 to 0.82), respectively. Combining high CRP values (>80 mg/L) and elevated white blood cell (WBC) count provided specificity >85%, positive likelihood ratios >3, but sensitivity <46% for both radiographic proven and bacterial pneumonia. CONCLUSION: With relatively high specificity and likelihood ratio CRP, WBC count and hypoxemia may be beneficial in ruling in a positive chest radiograph in suspected pneumonia and bacterial etiology in proven pneumonia, but with low sensitivity, the clinical utility is limited. What is Known: • Pneumonia is recommended to be a clinical diagnosis, and neither clinical features nor inflammatory markers can reliably distinguish etiology. • The etiology of pneumonia has changed after routine pneumococcal conjugate vaccine. What is New: • High CRP and WBC counts were associated with infiltrates in children with suspected pneumonia and with bacterial infection in proven pneumonia. • In the post-pneumococcal vaccination era, viral etiology is expected, and in cases of pneumonia with low CRP and WBC counts, a watch-and-wait strategy for antibiotic treatment may be applied.

Etiology of Pneumonia in a Pediatric Population with High Pneumococcal Vaccine Coverage: A Prospective Study.

BACKGROUND: Improved Childhood Immunizations Programs, especially the introduction of pneumococcal vaccination, better diagnostic methods and the importance of reduced antibiotic misuse, make this a critical time to increase knowledge on the etiology of pediatric pneumonia. Our main objective was to identify the contribution of various microbiological species that causes pneumonia in previously healthy children and adolescents in a population with high pneumococcal conjugate vaccine coverage. METHODS: This prospective, observational study enrolled patients with clinical and radiological signs of pneumonia over a 2-year period. Both inpatients and outpatients were included. Paired sera, nasopharyngeal polymerase chain reaction and bacterial cultures from blood and pleura were analyzed to detect potential viral and bacterial causative pathogens. RESULTS: TWO HUNDRED AND SIXTY-FIVE: cases of clinical and radiological verified pneumonia were identified. The pneumococcal vaccine coverage was 85%. We identified a causative pathogen in 84.2% of all cases; 63.4% with single viral etiology, 11.3% with pneumococcus and 7.5% with mycoplasma infection. Respiratory syncytial virus was the most common pathogen in children younger than 5 years, whereas mycoplasma was the most common in older children. CONCLUSIONS: We identified the majority of 265 cases with radiology proven pneumonia as single viral infections, predominantly respiratory syncytial virus and a much lower proportion of bacterial causes. These findings may impact pneumonia management guidelines in areas where widespread pneumococcal vaccination is provided and contribute to reduced antibiotic overuse in pediatric pneumonia.