Etiology of Acute Lower Respiratory Illness Hospitalizations Among Infants in 4 Countries.

Background: Recent studies explored which pathogens drive the global burden of pneumonia hospitalizations among young children. However, the etiology of broader acute lower respiratory tract infections (ALRIs) remains unclear. Methods: Using a multicountry study (Albania, Jordan, Nicaragua, and the Philippines) of hospitalized infants and non-ill community controls between 2015 and 2017, we assessed the prevalence and severity of viral infections and coinfections. We also estimated the proportion of ALRI hospitalizations caused by 21 respiratory pathogens identified via multiplex real-time reverse transcription polymerase chain reaction with bayesian nested partially latent class models. Results: An overall 3632 hospitalized infants and 1068 non-ill community controls participated in the study and had specimens tested. Among hospitalized infants, 1743 (48.0%) met the ALRI case definition for the etiology analysis. After accounting for the prevalence in non-ill controls, respiratory syncytial virus (RSV) was responsible for the largest proportion of ALRI hospitalizations, although the magnitude varied across sites-ranging from 65.2% (95% credible interval, 46.3%-79.6%) in Albania to 34.9% (95% credible interval, 20.0%-49.0%) in the Philippines. While the fraction of ALRI hospitalizations caused by RSV decreased as age increased, it remained the greatest driver. After RSV, rhinovirus/enterovirus (range, 13.4%-27.1%) and human metapneumovirus (range, 6.3%-12.0%) were the next-highest contributors to ALRI hospitalizations. Conclusions: We observed substantial numbers of ALRI hospitalizations, with RSV as the largest source, particularly in infants aged <3 months. This underscores the potential for vaccines and long-lasting monoclonal antibodies on the horizon to reduce the burden of ALRI in infants worldwide.

Primary Series and Booster Coronavirus Disease 2019 Vaccine Effectiveness in a Cohort of Healthcare Workers in Albania During a BA.1 and BA.2 Variant Period, January-May 2022.

Background: Healthcare workers (HCWs) have experienced high rates of coronavirus disease 2019 (COVID-19) morbidity and mortality. We estimated COVID-19 2-dose primary series and monovalent booster vaccine effectiveness (VE) against symptomatic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron (BA.1 and BA.2) infection among HCWs in 3 Albanian hospitals during January-May 2022. Methods: Study participants completed weekly symptom questionnaires, underwent polymerase chain reaction (PCR) testing when symptomatic, and provided quarterly blood samples for serology. We estimated VE using Cox regression models (1 - hazard ratio), with vaccination status as the time-varying exposure and unvaccinated HCWs as the reference group, adjusting for potential confounders: age, sex, prior SARS-CoV-2 infection (detected by PCR, rapid antigen test, or serology), and household size. Results: At the start of the analysis period, 76% of 1462 HCWs had received a primary series, 10% had received a booster dose, and 9% were unvaccinated; 1307 (89%) HCWs had evidence of prior infection. Overall, 86% of primary series and 98% of booster doses received were BNT162b2. The median time interval from the second dose and the booster dose to the start of the analysis period was 289 (interquartile range [IQR], 210-292) days and 30 (IQR, 22-46) days, respectively. VE against symptomatic PCR-confirmed infection was 34% (95% confidence interval [CI], -36% to 68%) for the primary series and 88% (95% CI, 39%-98%) for the booster. Conclusions: Among Albanian HCWs, most of whom had been previously infected, COVID-19 booster dose offered improved VE during a period of Omicron BA.1 and BA.2 circulation. Our findings support promoting booster dose uptake among Albanian HCWs, which, as of January 2023, was only 20%. Clinical Trials Registration. NCT04811391.

Primary series COVID-19 vaccine effectiveness among healthcare workers in Albania, February-December 2021.

Background: Healthcare workers have experienced high rates of morbidity and mortality from coronavirus disease 2019 (COVID-19). Methods: A prospective cohort study was conducted in three Albanian hospitals between 19 February and 14 December 2021. All participants underwent polymerase chain reaction (PCR) and serological testing at enrolment, regular serology throughout, and PCR testing when symptomatic.Vaccine effectiveness (VE) against COVID-19 and against all severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infections (symptomatic or asymptomatic) was estimated. VE was estimated using a Cox regression model, with vaccination status as a time-varying variable. Findings: In total, 1504 HCWs were enrolled in this study; 70% had evidence of prior SARS-CoV-2 infection. VE was 65.1% [95% confidence interval (CI) 37.7-80.5] against COVID-19, 58.2% (95% CI 15.7-79.3) among participants without prior SARS-CoV-2 infection, and 73.6% (95% CI 24.3-90.8) among participants with prior SARS-CoV-2 infection. For BNT162b2 alone, VE was 69.5% (95% CI 44.5-83.2). During the period when the Delta variant was predominant, VE was 67.1% (95% CI 38.3-82.5). VE against SARS-CoV-2 infection for the full study period was 36.9% (95% CI 15.8-52.7). Interpretation: This study found moderate primary series VE against COVID-19 among healthcare workers in Albania. These results support the continued promotion of COVID-19 vaccination in Albania, and highlight the benefits of vaccination in populations with high levels of prior infection.

Respiratory Syncytial Virus Infection Among Hospitalized Infants in Four Middle-Income Countries.

BACKGROUND: Understanding respiratory syncytial virus (RSV) global epidemiology is important to inform future prevention strategies. METHODS: Hospitalized infants <1-year-old with acute illness were enrolled prospectively in Albania, Jordan, Nicaragua, and Philippines during respiratory seasons in 2015-2017. Medical chart review, parental interview, and post-discharge follow up were conducted. Respiratory specimens were tested using real-time RT-PCR for RSV. Infant characteristics associated with very severe illness (intensive care unit [ICU] admission or receipt of supplemental oxygen) were assessed using logistic regression to adjust for potential confounders (age, sex, study site, and preterm birth). RESULTS: Of 3634 enrolled hospitalized infants, 1129 (31%) tested positive for RSV. The median age of RSV-positive infants was 2.7 (IQR: 1.4-6.1) months and 665 (59%) were male. Very severe illness in 583 (52%) RSV-positive infants was associated with younger age (aOR 4.1, 95% CI: 2.6-6.5 for 0-2 compared to 9-11-months; P < .01), low weight-for-age z-score (aOR 1.9, 95% CI: 1.2-2.8; P < .01), ICU care after birth (aOR 1.6, 95% CI: 1.0-2.5; P = .048), and cesarean delivery (aOR 1.4, 95% CI: 1.0-1.8; P = .03). RSV subgroups A and B co-circulated at all sites with alternating predominance by year; subgroup was not associated with severity (aOR 1.0, 95% CI: 0.8-1.4). Nine (0.8%) RSV-positive infants died during admission or within ≤30 days of discharge, of which 7 (78%) were <6-months-old. CONCLUSIONS: RSV was associated with nearly a third of infant acute illness hospitalizations in four middle-income countries during the respiratory season, where, in addition to young age, factors including low weight-for-age might be important predictors of severity. RSV prevention strategies targeting young infants could substantially reduce RSV-associated hospitalizations in middle-income countries.

Factors associated with receipt of COVID-19 vaccination and SARS-CoV-2 seropositivity among healthcare workers in Albania (February 2021-June 2022): secondary analysis of a prospective cohort study.

Background: Healthcare workers (HCWs) have been disproportionally affected by COVID-19. We investigated factors associated with two- and three-dose COVID-19 vaccine uptake and SARS-CoV-2 seropositivity among 1504 HCWs enrolled (19 February-7 May 2021) in a prospective COVID-19 vaccine effectiveness cohort in Albania through a secondary analysis. Methods: We collected sociodemographic, occupational, health, prior SARS-CoV-2 infection, and COVID-19 vaccination data from all HCWs at enrollment. Vaccination status was assessed weekly through June 2022. A serum sample was collected from all participants at enrollment and tested for anti-spike SARS-CoV-2 antibodies. We analyzed HCWs characteristics and outcomes using multivariable logistic regression. Findings: By 11 June 2022, 1337 (88.9%) HCWs had received two COVID-19 vaccine doses, of whom 255 (19.1%) received a booster. Factors significantly associated with receiving three doses (adjusted odds ratio (aOR), 95% CIs) were being ≥35 years (35-44 years: 1.76 (1.05-2.97); 45-54 years: 3.11 (1.92-5.05); ≥55 years: 3.38 (2.04-5.59)) and vaccinated against influenza (1.78; 1.20-2.64). Booster dose receipt was lower among females (0.58; 0.41-0.81), previously infected (0.67; 0.48-0.93), nurses and midwives (0.31; 0.22-0.45), and support staff (0.19; 0.11-0.32). Overall 1076 (72%) were SARS-CoV-2 seropositive at enrollment. Nurses and midwifes (1.45; 1.05-2.02), support staff (1.57; 1.03-2.41), and HCWs performing aerosol-generating procedures (AGPs) (1.40; 1.01-1.94) had higher odds of being seropositive, while smokers had reduced odds (0.55; 0.40-0.75). Interpretation: In a large cohort of Albanian HCWs, COVID-19 vaccine booster dose uptake was very low, particularly among younger, female, and non-physician HCWs, despite evidence demonstrating the added benefit of boosters in preventing infection and severe disease. Reasons behind these disparities should be explored to develop targeted strategies in order to promote uptake in this critical population. SARS-CoV-2 seroprevalence was higher among non-physicians and HCWs performing APGs. A better understanding of the factors contributing to these differences is needed to inform interventions that could reduce infections in the future. Funding: This study was funded by the Task Force for Global Health (US Centers for Disease Control (CDC) cooperative agreement # NU51IP000873) and the World Health Organization, Regional Office for Europe.