ABSTRACT
As part of an ongoing study assessing homologous and heterologous booster vaccines, following primary EUA series, we assessed neutralization of D614G and Omicron variants prior to and 28 days after boost. Subset analysis was done in six combinations (N = 10/group): four homologous primary-booster combinations included mRNA-1273 two-dose priming followed by boosting with 100-g or 50-g mRNA-1273, Ad26.COV2.S single-dose priming followed by Ad26.COV2.S booster and BNT162b2 two-dose priming followed by BNT162b2 boosting; and two heterologous primary-booster combinations: BNT162b2 followed by Ad26.COV2.S and Ad26.COV2.S followed by BNT162b2. Neutralizing antibody (Nab) titers to D614G on the day of boost (baseline) were detected in 85-100% of participants, with geometric mean titers (GMT) of 71-343 in participants who received an mRNA vaccine series versus GMTs of 35-41 in participants primed with Ad26.OV2.S. Baseline NAb titers to Omicron were detected in 50-90% of participants who received an mRNA vaccine series (GMT range 12.8-24.5) versus 20-25% among participants primed with Ad26.COV2.S. The booster dose increased the neutralizing GMT in most combinations to above 1000 for D614G and above 250 for Omicron by Day 29. Homologous prime-boost Ad26.COV2.S had the lowest NAb on Day 29 (D614G GMT 128 and Omicron GMT 45). Results were similar between age groups. Most homologous and heterologous boost combinations examined will increase humoral immunity to the Omicron variant.
ABSTRACT
BackgroundLiterature suggests that antibiotic prescribing in COVID-19 patients is high, despite low rates of confirmed bacterial infection. There are little data on what drives prescribing habits. ObjectiveThis study sought to determine antibiotic prescribing rates and risk factors for antibiotic prescribing in hospitalized patients. It was the first study to assess risk factors for receiving more than one course of antibiotics. MethodsThis was a retrospective, multi-center, observational study. Patients admitted from March 1, 2020 to May 31, 2020 and treated for PCR-confirmed COVID-19 were included. The primary endpoint was the rate of antibiotic use during hospitalization. Secondary endpoints included risk factors associated with antibiotic use, risk factors associated with receiving more than one antibiotic course, and rate of microbiologically confirmed infections. ResultsA total of 208 encounters (198 patients) were included in the final analysis. Eighty-three percent of patients received at least one course of antibiotics, despite low rates of microbiologically confirmed infection (12%). Almost one-third of patients (30%) received more than one course of antibiotics. Risk factors identified for both antibiotic prescribing and receiving more than one course of antibiotics were more serious illness, increased hospital length of stay, intensive care unit admission, mechanical ventilation, and acute respiratory distress syndrome. Conclusion and relevanceThere were high rates of antibiotic prescribing with low rates of bacterial co-infection. Many patients received more than one course of antibiotics during hospitalization. This study highlights the need for increased antibiotic stewardship practices in COVID-19 patients.
