Acute Coxiella burnetii Infection: A 10-Year Clinical Experience at a Tertiary Care Center in the United States.

Background: Identifying and treating patients with acute Q fever who are at an increased risk of progressing to persistent disease is crucial for preventing future complications. In this study, we share our decade-long clinical experience with acute Q fever, highlighting the challenges that clinicians encounter from making an initial diagnosis and performing risk stratification to determining the appropriate prophylaxis regimen and duration. Methods: We retrieved records of adult Mayo Clinic patients (≥18 years) with positive Coxiella burnetii serology results between 1 January 2012 and 31 March 2022. Patients with Q fever anti-phase II immunoglobulin G ≥1:256 by indirect immunofluorescence were further analyzed. Results: Thirty-one patients were included. Their median age was 58 years (IQR, 50-64), and the majority were men (84%). Acute hepatitis (29%), flu-like illness (25.8%), and pneumonia (16%) were the most common presentations. Thirteen patients (42%) received antibiotic prophylaxis to prevent disease progression, with significant variation in the indications and duration across physicians. The combination of doxycycline and hydroxychloroquine was the preferred regimen. Prophylaxis was administered for a median 333 days (IQR, 168-414). Four patients (13%) progressed to Q fever native valve infective endocarditis, with elevated anticardiolipin immunoglobulin G levels being the sole risk factor in 2 cases. The small sample size precluded drawing conclusions on the impact of prophylaxis in preventing disease progression. Conclusions: Management of acute Q fever is complicated by the lack of comprehensive clinical guidelines leading to varied clinical practices. There is a critical need for randomized trials to establish robust evidence-based protocols for management.

Surveillance of Safety of 3 Doses of COVID-19 mRNA Vaccination Using Electronic Health Records.

Importance: Recent reports on waning of COVID-19 vaccine-induced immunity have led to the approval and rollout of additional doses and booster vaccinations. Individuals at increased risk of SARS-CoV-2 infection are receiving additional vaccine doses in addition to the regimen that was tested in clinical trials. Risks and adverse event profiles associated with additional vaccine doses are currently not well understood. Objective: To evaluate the safety of third-dose vaccination with US Food and Drug Administration (FDA)-approved COVID-19 mRNA vaccines. Design, Setting, and Participants: This cohort study was conducted using electronic health record (EHR) data from December 2020 to October 2021 from the multistate Mayo Clinic Enterprise. Participants included all 47 999 individuals receiving 3-dose COVID-19 mRNA vaccines within the study setting who met study inclusion criteria. Participants were divided into 2 cohorts by vaccine brand administered and served as their own control groups, with no comparison made between cohorts. Data were analyzed from September through November 2021. Exposures: Three doses of an FDA-authorized COVID-19 mRNA vaccine, BNT162b2 or mRNA-1273. Main Outcomes and Measures: Vaccine-associated adverse events were assessed via EHR report. Adverse event risk was quantified using the percentage of study participants who reported the adverse event within 14 days after each vaccine dose and during a 14-day control period, immediately preceding the first vaccine dose. Results: Among 47 999 individuals who received 3-dose COVID-19 mRNA vaccines, 38 094 individuals (21 835 [57.3%] women; median [IQR] age, 67.4 [52.5-76.5] years) received BNT162b2 (79.4%) and 9905 individuals (5099 [51.5%] women; median [IQR] age, 67.7 [59.5-73.9] years) received mRNA-1273 (20.6%). Reporting of severe adverse events remained low after the third vaccine dose, with rates of pericarditis (0.01%; 95% CI, 0%-0.02%), anaphylaxis (0%; 95% CI, 0%-0.01%), myocarditis (0%; 95% CI, 0%-0.01%), and cerebral venous sinus thrombosis (no individuals) consistent with results from earlier studies. Significantly more individuals reported low-severity adverse events after the third dose compared with after the second dose, including fatigue (2360 individuals [4.92%] vs 1665 individuals [3.47%]; P < .001), lymphadenopathy (1387 individuals [2.89%] vs 995 individuals [2.07%]; P < .001), nausea (1259 individuals [2.62%] vs 979 individuals [2.04%]; P < .001), headache (1185 individuals [2.47%] vs 992 individuals [2.07%]; P < .001), arthralgia (1019 individuals [2.12%] vs 816 individuals [1.70%]; P < .001), myalgia (956 individuals [1.99%] vs 784 individuals [1.63%]; P < .001), diarrhea (817 individuals [1.70%] vs 595 individuals [1.24%]; P < .001), fever (533 individuals [1.11%] vs 391 individuals [0.81%]; P < .001), vomiting (528 individuals [1.10%] vs 385 individuals [0.80%]; P < .001), and chills (224 individuals [0.47%] vs 175 individuals [0.36%]; P = .01). Conclusions and Relevance: This study found that although third-dose vaccination against SARS-CoV-2 infection was associated with increased reporting of low-severity adverse events, risk of severe adverse events remained comparable with risk associated with the standard 2-dose regime. These findings suggest the safety of third vaccination doses in individuals who were eligible for booster vaccination at the time of this study.

Durability analysis of the highly effective mRNA-1273 vaccine against COVID-19.

COVID-19 vaccines are effective, but breakthrough infections have been increasingly reported. We conducted a test-negative case-control study to assess the durability of protection against symptomatic infection after vaccination with mRNA-1273. We fit conditional logistic regression (CLR) models stratified on residential county and calendar date of SARS-CoV-2 PCR testing to assess the association between the time elapsed since vaccination and the odds of symptomatic infection, adjusted for several covariates. There were 2,364 symptomatic individuals who had a positive SARS-CoV-2 PCR test after full vaccination with mRNA-1273 ("cases") and 12,949 symptomatic individuals who contributed 15,087 negative tests after full vaccination ("controls"). The odds of symptomatic infection were significantly higher 250 days after full vaccination compared to the date of full vaccination (Odds Ratio [OR]: 2.47, 95% confidence interval [CI]: 1.19-5.13). The odds of non-COVID-19 associated hospitalization and non-COVID-19 pneumonia (negative control outcomes) remained relatively stable over the same time interval (Day 250 ORNon-COVID Hospitalization: 0.68, 95% CI: 0.47-1.0; Day 250 ORNon-COVID Pneumonia: 1.11, 95% CI: 0.24-5.2). The odds of symptomatic infection remained significantly lower almost 300 days after the first mRNA-1273 dose as compared to 4 days after the first dose, when immune protection approximates the unvaccinated state (OR: 0.26, 95% CI: 0.17-0.39). Low rates of COVID-19 associated hospitalization or death in this cohort precluded analyses of these severe outcomes. In summary, mRNA-1273 robustly protected against symptomatic SARS-CoV-2 infection at least 8 months after full vaccination, but the degree of protection waned over this time period.