Tecovirimat Resistance in Mpox Patients, United States, 2022-2023.

During the 2022 multinational outbreak of monkeypox virus (MPXV) infection, the antiviral drug tecovirimat (TPOXX; SIGA Technologies, Inc., https://www.siga.com) was deployed in the United States on a large scale for the first time. The MPXV F13L gene homologue encodes the target of tecovirimat, and single amino acid changes in F13 are known to cause resistance to tecovirimat. Genomic sequencing identified 11 mutations previously reported to cause resistance, along with 13 novel mutations. Resistant phenotype was determined using a viral cytopathic effect assay. We tested 124 isolates from 68 patients; 96 isolates from 46 patients were found to have a resistant phenotype. Most resistant isolates were associated with severely immunocompromised mpox patients on multiple courses of tecovirimat treatment, whereas most isolates identified by routine surveillance of patients not treated with tecovirimat remained sensitive. The frequency of resistant viruses remains relatively low (<1%) compared with the total number of patients treated with tecovirimat.

Use of Ebola Vaccine: Recommendations of the Advisory Committee on Immunization Practices, United States, 2020.

This report summarizes the recommendations of the Advisory Committee on Immunization Practices (ACIP) for use of the rVSVΔG-ZEBOV-GP Ebola vaccine (Ervebo) in the United States. The vaccine contains rice-derived recombinant human serum albumin and live attenuated recombinant vesicular stomatitis virus (VSV) in which the gene encoding the glycoprotein of VSV was replaced with the gene encoding the glycoprotein of Ebola virus species Zaire ebolavirus. Persons with a history of severe allergic reaction (e.g., anaphylaxis) to rice protein should not receive Ervebo. This is the first and only vaccine currently licensed by the Food and Drug Administration for the prevention of Ebola virus disease (EVD). These guidelines will be updated based on availability of new data or as new vaccines are licensed to protect against EVD.ACIP recommends preexposure vaccination with Ervebo for adults aged ≥18 years in the U.S. population who are at highest risk for potential occupational exposure to Ebola virus species Zaire ebolavirus because they are responding to an outbreak of EVD, work as health care personnel at federally designated Ebola treatment centers in the United States, or work as laboratorians or other staff at biosafety level 4 facilities in the United States. Recommendations for use of Ervebo in additional populations at risk for exposure and other settings will be considered and discussed by ACIP in the future.

Safety of Antimicrobials During Pregnancy: A Systematic Review of Antimicrobials Considered for Treatment and Postexposure Prophylaxis of Plague.

BACKGROUND: The safety profile of antimicrobials used during pregnancy is one important consideration in the decision on how to treat and provide postexposure prophylaxis (PEP) for plague during pregnancy. METHODS: We searched 5 scientific literature databases for primary sources on the safety of 9 antimicrobials considered for plague during pregnancy (amikacin, gentamicin, plazomicin, streptomycin, tobramycin, chloramphenicol, doxycycline, sulfadiazine, and trimethoprim-sulfamethoxazole [TMP-SMX]) and abstracted data on maternal, pregnancy, and fetal/neonatal outcomes. RESULTS: Of 13 052 articles identified, 66 studies (case-control, case series, cohort, and randomized studies) and 96 case reports were included, totaling 27 751 prenatal exposures to amikacin (n = 9), gentamicin (n = 345), plazomicin (n = 0), streptomycin (n = 285), tobramycin (n = 43), chloramphenicol (n = 246), doxycycline (n = 2351), sulfadiazine (n = 870), and TMP-SMX (n = 23 602). Hearing or vestibular deficits were reported in 18/121 (15%) children and 17/109 (16%) pregnant women following prenatal streptomycin exposure. First trimester chloramphenicol exposure was associated with an elevated risk of an undescended testis (odds ratio [OR] 5.9, 95% confidence interval [CI] 1.2-28.7). Doxycycline was associated with cardiovascular malformations (OR 2.4, 95% CI 1.2-4.7) in 1 study and spontaneous abortion (OR 2.8, 95% CI 1.9-4.1) in a separate study. First trimester exposure to TMP-SMX was associated with increased risk of neural tube defects (pooled OR 2.5, 95% CI 1.4-4.3), spontaneous abortion (OR 3.5, 95% CI 2.3-5.6), preterm birth (OR 1.5, 95% CI 1.1-2.1), and small for gestational age (OR 1.6, 95% CI 1.2-2.2). No other statistically significant associations were reported. CONCLUSIONS: For most antimicrobials reviewed, adverse maternal/fetal/neonatal outcomes were not observed consistently. Prenatal exposure to streptomycin and TMP-SMX was associated with select birth defects in some studies. Based on limited data, chloramphenicol and doxycycline may be associated with adverse pregnancy or neonatal outcomes; however, more data are needed to confirm these associations. Antimicrobials should be used for treatment and PEP of plague during pregnancy; the choice of antimicrobials may be influenced by these data as well as information about the risks of plague during pregnancy.

Preemptive Tecovirimat Use in an Active Duty Service Member Who Presented With Acute Myeloid Leukemia After Smallpox Vaccination.

Smallpox vaccine is contraindicated in immunosuppression due to increased risk for adverse reactions (eg, progressive vaccinia). We describe the first-ever use of tecovirimat as a preemptive vaccinia virus treatment strategy during induction chemotherapy in an active duty service member who presented with acute leukemia and inadvertent autoinoculation after smallpox vaccination.

Novel Treatment of a Vaccinia Virus Infection from an Occupational Needlestick - San Diego, California, 2019.

Vaccinia virus (VACV) is an orthopoxvirus used in smallpox vaccines, as a vector for novel cancer treatments, and for experimental vaccine research (1). The Advisory Committee on Immunization Practices (ACIP) recommends smallpox vaccination for laboratory workers who handle replication-competent VACV (1). For bioterrorism preparedness, the U.S. government stockpiles tecovirimat, the first Food and Drug Administration-approved antiviral for treatment of smallpox (caused by variola virus and globally eradicated in 1980*,†) (2). Tecovirimat has activity against other orthopoxviruses and can be administered under a CDC investigational new drug protocol. CDC was notified about an unvaccinated laboratory worker with a needlestick exposure to VACV, who developed a lesion on her left index finger. CDC and partners performed laboratory confirmation, contacted the study sponsor to identify the VACV strain, and provided oversight for the first case of laboratory-acquired VACV treated with tecovirimat plus intravenous vaccinia immunoglobulin (VIGIV). This investigation highlights 1) the misconception among laboratory workers about the virulence of VACV strains; 2) the importance of providing laboratorians with pathogen information and postexposure procedures; and 3) that although tecovirimat can be used to treat VACV infections, its therapeutic benefit remains unclear.

Food selection and effect of home preparation procedure for antibiotic food mixtures on homogeneity, stability, and dissolution.

Amoxicillin, doxycycline, and clindamycin are among the commonly used antibiotics to treat bacterial infections. However, dosage forms of antibiotics for pediatric patients may not be as readily available as the formulations for adult patients. As such, it is anticipated that during a public health emergency, special instruction may need to be provided on home preparation and administration procedures to dose pediatric patients using available stockpiles of oral tablet and capsule dosage forms. Mixing crushed tablets or capsule contents with soft- or liquid- foods is one of the most common home preparation procedures. To gain knowledge for safe and effective use of prepared drug product instead of the intended intact dosage form, the impact of manipulation of the dosage form was studied. Capsule opening, capsule content assay and uniformity, dissolution, homogeneity, and stability studies of drug mixed with various liquid and soft foods were carried out using intact capsules of amoxicillin, doxycycline, and clindamycin. Higher recovery of capsule contents was achieved when using hands or knives to open capsules compared to using scissors. The capsules of all three antibiotic products contained the labeled amount of active pharmaceutical ingredients (API). The peanut butter-drug mixtures failed both United States Pharmacopeia (USP) assay and dissolution criteria because the peanut butter significantly affected the solubility of the drugs, and hence it was omitted from further study. All drug-food mixtures of the three antibiotic products and 15 selected foods exhibited fast dissolution (e.g., >80 % in 60 min) in the tested medium, except for the amoxicillin-chocolate pudding mixture. Three household containers (cups, plates, and bowls) and four mixing times (0.5 min, 1 min, 2 min, and 5 min) were found to be suitable for preparation of homogeneous mixtures of the antibiotics and foods. For practical purposes, 1 to 2 min mixing time is sufficient to produce homogeneous mixtures. The results of this study provided product quality data on the interactions between the antibiotics and the foods and can potentially support future development of home preparation instructions of antibiotics for pediatric patients or patients with swallowing difficulties.