Clinical Infectious Diseases: An Official Publication of the Infectious Diseases Society of America最新文献

Background: In Singapore, quarantine of all close contacts with entry and exit polymerase chain reaction testing enabled evaluation of the impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination and pediatric age on transmission of the Delta variant.

Methods: This retrospective cohort study included all household close contacts between 1 March 2021 and 31 August 2021.

Results: Among 8470 Delta variant-exposed contacts linked to 2583 indices, full-vaccination of the index with BNT162b2 or mRNA-1273 was associated with reduction in acquisition by contacts (adjusted odds ratio [aOR], 0.56; 95% robust confidence interval [RCI], .44-.71 and aOR, 0.51; 95% RCI, .27-.96, respectively). Compared with young adults (aged 18-29 years), children (aged 0-11 years) were significantly more likely to transmit (aOR, 2.37; 95% RCI, 1.57-3.60) and acquire (aOR, 1.43; 95% RCI, 1.07-1.93) infection, vaccination considered. Longer duration from vaccination completion among contacts was associated with decline in protection against acquisition (first-month aOR, 0.42; 95% RCI, .33-.55; fifth-month aOR, 0.84; 95% RCI, .55-.98; P < .0001 for trend) and symptomatic disease (first-month aOR, 0.30; 95% RCI, .23-.41; fifth-month aOR, 0.62; 95% RCI, .38-1.02; P < .0001 for trend). Contacts immunized with mRNA-1273 had significant reduction in acquisition (aOR, 0.73; 95% RCI, .58-.91) compared with BNT162b2.

Conclusions: Among household close contacts, vaccination prevented onward SARS-CoV-2 transmission and there was in-creased risk of SARS-CoV-2 acquisition and transmission among children compared with young adults. Time after completion of vaccination and vaccine type affected SARS-CoV-2 acquisition.

Background: In 2010, the World Health Organization (WHO) revised dosing guidelines for treatment of childhood tuberculosis. Our aim was to investigate first-line antituberculosis drug exposures under these guidelines, explore dose optimization using the current dispersible fixed-dose combination (FDC) tablet of rifampicin/isoniazid/pyrazinamide; 75/50/150 mg, and suggest a new FDC with revised weight bands.

Methods: Children with drug-susceptible tuberculosis in Malawi and South Africa underwent pharmacokinetic sampling while receiving first-line tuberculosis drugs as single formulations according the 2010 WHO recommended doses. Nonlinear mixed-effects modeling and simulation was used to design the optimal FDC and weight-band dosing strategy for achieving the pharmacokinetic targets based on literature-derived adult AUC0-24h for rifampicin (38.7-72.9), isoniazid (11.6-26.3), and pyrazinamide (233-429 mg ∙ h/L).

Results: In total, 180 children (42% female; 13.9% living with human immunodeficiency virus [HIV]; median [range] age 1.9 [0.22-12] years; weight 10.7 [3.20-28.8] kg) were administered 1, 2, 3, or 4 FDC tablets (rifampicin/isoniazid/pyrazinamide 75/50/150 mg) daily for 4-8, 8-12, 12-16, and 16-25 kg weight bands, respectively. Rifampicin exposure (for weight and age) was up to 50% lower than in adults. Increasing the tablet number resulted in adequate rifampicin but relatively high isoniazid and pyrazinamide exposures. Administering 1, 2, 3, or 4 optimized FDC tablets (rifampicin/isoniazid/pyrazinamide 120/35/130 mg) to children < 6, 6-13, 13-20. and 20-25 kg, and 0.5 tablet in < 3-month-olds with immature metabolism, improved exposures to all 3 drugs.

Conclusions: Current pediatric FDC doses resulted in low rifampicin exposures. Optimal dosing of all drugs cannot be achieved with the current FDCs. We propose a new FDC formulation and revised weight bands.

Background: Most studies on health disparities during the coronavirus disease 2019 (COVID-19) pandemic focused on reported cases and deaths, which are influenced by testing availability and access to care. This study aimed to examine severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody seroprevalence in the United States and its associations with race/ethnicity, rurality, and social vulnerability over time.

Methods: This repeated cross-sectional study used data from blood donations in 50 states and Washington, DC, from July 2020 through June 2021. Donor zip codes were matched to counties and linked with Social Vulnerability Index (SVI) and urban-rural classification. SARS-CoV-2 antibody seroprevalences induced by infection and infection-vaccination combined were estimated. Association of infection-induced seropositivity with demographics, rurality, SVI, and its 4 themes were quantified using multivariate regression models.

Results: Weighted seroprevalence differed significantly by race/ethnicity and rurality, and increased with increasing social vulnerability. During the study period, infection-induced seroprevalence increased from 1.6% to 27.2% and 3.7% to 20.0% in rural and urban counties, respectively, while rural counties had lower combined infection- and vaccination-induced seroprevalence (80.0% vs 88.1%) in June 2021. Infection-induced seropositivity was associated with being Hispanic, non-Hispanic Black, and living in rural or more socially vulnerable counties, after adjusting for demographic and geographic covariates.

Conclusions: The findings demonstrated increasing SARS-CoV-2 seroprevalence in the United States across all geographic, demographic, and social sectors. The study illustrated disparities by race-ethnicity, rurality, and social vulnerability. The findings identified areas for targeted vaccination strategies and can inform efforts to reduce inequities and prepare for future outbreaks.

Background: Vaccines against coronavirus disease 2019 (COVID-19) are highly efficacious, but severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections do occur after vaccination. We characterized COVID-19 cases among fully vaccinated persons with an outcome of death.

Methods: We analyzed COVID-19 cases voluntarily reported to the Centers for Disease Control and Prevention by US health departments from 1 January to 30 April 2021. We included cases among US residents with a positive SARS-CoV-2 test result ≥14 days after completion of an authorized primary vaccine series and who had a known outcome (alive or dead) as of 31 May 2021. When available, specimens were sequenced for viral lineage and death certificates were reviewed for cause(s) of death.

Results: Of 8084 fully vaccinated persons with reported COVID-19 during the surveillance period, 245 (3.0%) died. Compared with patients who remained alive, those who died were older (median age, 82 vs 57 years;), more likely to reside in a long-term care facility (51% vs 18%), and more likely to have ≥1 underlying health condition associated with risk for severe disease (64% vs 24%) (all P < .01). Among 245 deaths, 191 (78%) were classified as COVID-19 related. Of 106 deaths with available death certificates, COVID-19 was listed for 81 deaths (77%). There were no differences in the type of vaccine administered or the most common viral lineage (B.1.1.7).

Conclusions: COVID-19 deaths are rare in fully vaccinated persons, occurring most commonly in those with risk factors for severe disease, including older age and underlying health conditions. All eligible persons should be fully vaccinated against COVID-19 and follow other prevention measures to mitigate exposure risk.

Background: Rotavirus vaccine efficacy is reduced in low-income populations, but efforts to improve vaccine performance are limited by lack of clear correlates of protection. Although plasma rotavirus (RV)-specific immunoglobulin A (IgA) appears strongly associated with protection against rotavirus gastroenteritis in high-income countries, weaker association has been observed in low-income countries. We tested the hypothesis that lower RV-specific IgA is associated with rotavirus vaccine failure in Malawian infants.

Methods: In a case-control study, we recruited infants presenting with severe rotavirus gastroenteritis following monovalent oral rotavirus vaccination (RV1 vaccine failures). Conditional logistic regression was used to determine the odds of rotavirus seronegativity (RV-specific IgA < 20 U/mL) in these cases compared 1:1 with age-matched, vaccinated, asymptomatic community controls. Plasma RV-specific IgA was determined by enzyme-linked immunosorbent assay for all participants at recruitment, and for cases at 10 days after symptom onset. Rotavirus infection and genotype were determined by antigen testing and reverse transcription-polymerase chain reaction, respectively.

Results: In 116 age-matched pairs, infants with RV1 vaccine failure were more likely to be RV-specific IgA seronegative than controls: odds ratio, 3.1 (95% confidence interval [CI], 1.6-5.9), P=.001. In 60 infants with convalescent serology, 42/45 (93%; 95% CI. 81-98) infants seronegative at baseline became seropositive. Median rise in RV-specific IgA concentration following acute infection was 112.8 (interquartile range, 19.1-380.6)-fold.

Conclusions: In this vaccinated population with high residual burden of rotavirus disease, RV1 vaccine failure was associated with lower RV-specific IgA, providing further evidence of RV-specific IgA as a marker of protection. Robust convalescent RV-specific IgA response in vaccine failures suggests differences in wild-type and vaccine-induced immunity, which informs future vaccine development.

Background: Coronavirus disease 2019 (COVID-19) vaccines are implemented worldwide in efforts to curb the pandemic. This study investigates the risk of a positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reverse transcriptase polymerase chain reaction (RT-PCR) test following BNT162b2 vaccination in a large real-life population in Denmark.

Methods: Vaccination status and positive SARS-CoV-2 RT-PCR results from adults in the Capital Region of Denmark (n = 1 549 488) were obtained from national registries. PCR testing was free and widely available. The number of positive PCR tests per individual at risk was calculated as weekly rates. Time to positive PCR test was modelled using Kaplan-Meier methods and hazard ratios (HRs) were calculated using Cox regression.

Results: A total of 1 119 574 individuals received the first dose of BNT162b2 and 1 088 879 received a second dose of BNT162b2. Individuals were followed up to 8.7 months after first dose (median: 5.5 months; interquartile ratio: 4.1-8.7). Rates of PCR-confirmed SARS-CoV-2 infection 2-4 months after the second dose were 0.21, 0.33, and 0.36 per 1000 individuals per week at risk for July, August, and September, respectively. Four or more months after the second dose, the rates were 0.56, 0.76, and 0.53 per 1000 individuals per week at risk for July, August, and September, respectively. HR of SARS-CoV-2 infection after the second dose was 0.2 (95% confidence interval, .05-.48; P = .001) for individuals with 8 months' follow-up.

Conclusions: Individuals who received 2 doses of the BNT162b2 COVID-19 vaccine had a low risk of breakthrough infection after up to 8 months of follow-up. However, there was a tendency toward higher rates with longer follow-up.

The coronavirus disease 2019 (COVID-19) pandemic continues to pose substantial risks to public health, worsened by the emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants that may have a higher transmissibility and reduce vaccine effectiveness. We conducted a systematic review and meta-analysis on reproduction numbers of SARS-CoV-2 variants and provided pooled estimates for each variant.

Background: Remdesivir (RDV) improved clinical outcomes among hospitalized patients with coronavirus disease 2019 (COVID-19) in randomized trials, but data from clinical practice are limited.

Methods: We examined survival outcomes for US patients hospitalized with COVID-19 between August and November 2020 and treated with RDV within 2 days of hospitalization vs those not receiving RDV during their hospitalization using the Premier Healthcare Database. Preferential within-hospital propensity score matching with replacement was used. Additionally, patients were also matched on baseline oxygenation level (no supplemental oxygen charges [NSO], low-flow oxygen [LFO], high-flow oxygen/noninvasive ventilation [HFO/NIV], and invasive mechanical ventilation/extracorporeal membrane oxygenation [IMV/ECMO]) and 2-month admission window and excluded if discharged within 3 days of admission (to exclude anticipated discharges/transfers within 72 hours, consistent with the Adaptive COVID-19 Treatment Trial [ACTT-1] study). Cox proportional hazards models were used to assess time to 14-/28-day mortality overall and for patients on NSO, LFO, HFO/NIV, and IMV/ECMO.

Results: A total of 28855 RDV patients were matched to 16687 unique non-RDV patients. Overall, 10.6% and 15.4% RDV patients died within 14 and 28 days, respectively, compared with 15.4% and 19.1% non-RDV patients. Overall, RDV was associated with a reduction in mortality at 14 days (hazard ratio [95% confidence interval]: 0.76 [0.70-0.83]) and 28 days (0.89 [0.82-0.96]). This mortality benefit was also seen for NSO, LFO, and IMV/ECMO at 14 days (NSO: 0.69 [0.57-0.83], LFO: 0.68 [0.80-0.77], IMV/ECMO: 0.70 [0.58-0.84]) and 28 days (NSO: 0.80 [0.68-0.94], LFO: 0.77 [0.68-0.86], IMV/ECMO: 0.81 [0.69-0.94]). Additionally, HFO/NIV RDV group had a lower risk of mortality at 14 days (0.81 [0.70-0.93]) but no statistical significance at 28 days.

Conclusions: RDV initiated upon hospital admission was associated with improved survival among patients with COVID-19. Our findings complement ACTT-1 and support RDV as a foundational treatment for hospitalized COVID-19 patients.

Background: There is an urgent need to understand the real-world effectiveness of remdesivir in the treatment of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Methods: This was a retrospective comparative effectiveness study. Individuals hospitalized in a large private healthcare network in the United States from 23 February 2020 through 11 February 2021 with a positive test for SARS-CoV-2 and ICD-10 diagnosis codes consistent with symptomatic coronavirus disease 2019 (COVID-19) were included. Remdesivir recipients were matched to controls using time-dependent propensity scores. The primary outcome was time to improvement with a secondary outcome of time to death.

Results: Of 96 859 COVID-19 patients, 42 473 (43.9%) received at least 1 remdesivir dose. The median age of remdesivir recipients was 65 years, 23 701 (55.8%) were male, and 22 819 (53.7%) were non-White. Matches were found for 18 328 patients (43.2%). Remdesivir recipients were significantly more likely to achieve clinical improvement by 28 days (adjusted hazard ratio [aHR] 1.19, 95% confidence interval [CI], 1.16-1.22). Remdesivir patients on no oxygen (aHR 1.30, 95% CI, 1.22-1.38) or low-flow oxygen (aHR 1.23, 95% CI, 1.19-1.27) were significantly more likely to achieve clinical improvement by 28 days. There was no significant impact on the likelihood of mortality overall (aHR 1.02, 95% CI, .97-1.08). Remdesivir recipients on low-flow oxygen were significantly less likely to die than controls (aHR 0.85, 95% CI, .77-.92; 28-day mortality 8.4% [865 deaths] for remdesivir patients, 12.5% [1334 deaths] for controls).

Conclusions: These results support the use of remdesivir for hospitalized COVID-19 patients on no or low-flow oxygen. Routine initiation of remdesivir in more severely ill patients is unlikely to be beneficial.

Background: Takeda's live attenuated tetravalent dengue vaccine candidate (TAK-003) is under evaluation in a long-term clinical trial across 8 dengue-endemic countries. Previously, we have reported its efficacy and safety in both seronegative and seropositive participants and that its performance varies by serotype, with some decline in efficacy from first to second year postvaccination. This exploratory analysis provides an update with cumulative and third-year data.

Methods: Healthy 4-16 year olds (n = 20099) were randomized 2:1 to receive TAK-003 or placebo (0, 3 month schedule). The protocol included baseline serostatus testing of all participants and detection of all symptomatic dengue throughout the trial with a serotype specific reverse transcriptase-polymerase chain reaction.

Results: Cumulative efficacy after 3 years was 62.0% (95% confidence interval, 56.6-66.7) against virologically confirmed dengue (VCD) and 83.6% (76.8-88.4) against hospitalized VCD. Efficacy was 54.3% (41.9-64.1) against VCD and 77.1% (58.6-87.3) against hospitalized VCD in baseline seronegatives, and 65.0% (58.9-70.1) against VCD and 86.0% (78.4-91.0) against hospitalized VCD in baseline seropositives. Efficacy against VCD during the third year declined to 44.7% (32.5-54.7), whereas efficacy against hospitalized VCD was sustained at 70.8% (49.6-83.0). Rates of serious adverse events were 2.9% in TAK-003 group and 3.5% in placebo group during the ongoing long-term follow-up (ie, second half of the 3 years following vaccination), but none were related. No important safety risks were identified.

Conclusions: TAK-003 was efficacious against symptomatic dengue over 3 years. Efficacy declined over time but remained robust against hospitalized dengue. A booster dose evaluation is planned.