SARS-CoV-2 detection in pediatric dental clinic wastewater reflects the number of local COVID-19 cases in children under 10 years old.

This was the first longitudinal study to analyze dental clinic wastewater to estimate asymptomatic SARS-CoV-2 infection trends in children. We monitored wastewater over a 14-month period, spanning three major COVID-19 waves driven by the Alpha, Delta, and Omicron variants. Each Saturday, wastewater was sampled at the Pediatric Dental Clinic of the only dental hospital in Japan's Saitama Prefecture. The relationship between the weekly number of cases in Saitama Prefecture among residents aged < 10 years (exposure) and wastewater SARS-CoV-2 RNA detection (outcome) was examined. The number of cases was significantly associated with wastewater SARS-CoV-2 RNA positivity (risk ratio, 5.36; 95% confidence interval, 1.72-16.67; Fisher's exact test, p = 0.0005). A sample from Week 8 of 2022 harbored the Omicron variant. Compared to sporadic individual testing, this approach allows continuous population-level surveillance, which is less affected by healthcare seeking and test availability. Since wastewater from pediatric dental clinics originates from the oral cavities of asymptomatic children, such testing can provide important information regarding asymptomatic COVID-19 in children, complementing clinical pediatric data.

Lowering the Acquisition of Multi-drug Resistant Organism (MDROs) with Pulsed-xenon (LAMP) Study: a cluster randomized controlled, double-blinded, interventional crossover trial.

BACKGROUND: Environmental disinfection is essential for reducing spread of healthcare associated infections (HAIs). Previous studies report conflicting results regarding the effects of ultraviolet light (UV) in reducing infections. This trial evaluated the impact of adding pulsed xenon UV (PX-UV) to standard terminal cleaning in reducing environmentally-implicated HAIs (eiHAIs). METHODS: The LAMP trial was conducted in 2 hospitals (15 inpatient wards) utilizing a cluster randomized controlled, double-blinded, interventional crossover trial comparing standard terminal cleaning followed by either pulsed xenon ultraviolet (PX-UV) disinfection (intervention arm) or sham disinfection (control arm). The primary outcome was incidence of eiHAIs from clinical microbiology tests on the 4th day of stay or later or within 3 days after discharge from the study unit. EiHAIs included clinical cultures positive for vancomycin-resistant enterococci (VRE), extended spectrum beta-lactamase-producing Escherichia coli or Klebsiella pneumonia, methicillin-resistant Staphylococcus aureus (MRSA), and Acinetobacter baumannii, and stool PCR positive for Clostridiodes difficile. FINDINGS: Between May 18, 2017 to Jan 7, 2020, 25,732 patients were included, with an incidence of 601 eiHAI and 180,954 patient days. There was no difference in the rate of eiHAIs in the intervention and sham arms (3.49 vs 3.17 infections/1000 patient days respectively, RR 1.10 CI (0.94, 1.29, p= 0.23)). Study results were similar when stratified by eiHAI type, hospital, and unit type. CONCLUSION: The LAMP study failed to demonstrate an effect of the addition of UV light disinfection following terminal cleaning on reductions in rates of eiHAIs. Further investigations targeting hospital environmental surfaces and the role of no touch technology to reduce HAIs are needed.

Control of SARS-CoV-2 infection in skilled nursing facilities in Detroit, Michigan: a model for emerging infectious diseases.

An infection prevention bundle that consisted of the development of a response team, public-academic partnership, daily assessment, regular testing, isolation, and environmental controls was implemented in 26 skilled nursing facilities in Detroit, Michigan (March 2020-April 2021). This intervention was associated with sustained control of severe acute respiratory coronavirus virus 2 infection among residents and staff.

Vaccine administration by pharmacy technicians: Impact on vaccination volume, pharmacy workflow and job satisfaction.

Background: Immunizing pharmacy technicians (IPTs) have become more prevalent in recent years, but their impact on community pharmacy practice has yet to be determined. Objectives: Determine the impact of implementing IPTs on vaccination volume in a community pharmacy chain and assess pharmacy staff's perspectives on the clinical abilities of IPTs and their impact on pharmacy workflow and job satisfaction. Methods: Retrospective data analysis comparing the number of vaccines administered in a supermarket pharmacy chain from September to March 2019-2020 and 2020-2021 in pharmacies with IPT(s) versus those without IPT(s). For the secondary objective, investigators developed and deployed two role-based mixed quantitative/qualitative surveys among pharmacy staff. Results: Pharmacies with IPT(s) observed a greater mean increase in vaccination volume from 2019-2020 to 2020-2021 versus those without IPTs (+159.35 vs. +104.57, p = 0.011). Among IPT survey respondents, 50/75 (66.7%) felt more satisfied with their job after receiving immunization training. Among pharmacist respondents, 80/119 (67.3%) felt that IPTs positively impacted their job satisfaction and 61.7% felt that pharmacist clinical services were either somewhat positively affected, or positively affected. Conclusion: Implementing IPTs can increase the volume of vaccines administered in a chain pharmacy and may positively affect job satisfaction and pharmacy workflow.

A Bacteriophage Cocktail Targeting Yersinia pestis Provides Strong Post-Exposure Protection in a Rat Pneumonic Plague Model.

Yersinia pestis , one of the deadliest bacterial pathogens ever known, is responsible for three plague pandemics and several epidemics, with over 200 million deaths during recorded history. Due to high genomic plasticity, Y. pestis is amenable to genetic mutations as well as genetic engineering that can lead to the emergence or intentional development of pan-drug resistant strains. The dissemination of such Y. pestis strains could be catastrophic, with public health consequences far more daunting than those caused by the recent COVID-19 pandemic. Thus, there is an urgent need to develop novel, safe, and effective treatment approaches for managing Y. pestis infections. This includes infections by antigenically distinct strains for which vaccines, none FDA approved yet, may not be effective, and those that cannot be controlled by approved antibiotics. Lytic bacteriophages provide one such alternative approach. In this study, we examined post-exposure efficacy of a bacteriophage cocktail, YPP-401, to combat pneumonic plague caused by Y. pestis CO92. YPP-401 is a four-phage preparation with a 100% lytic activity against a panel of 68 genetically diverse Y. pestis strains. Using a pneumonic plague aerosol challenge model in gender-balanced Brown Norway rats, YPP-401 demonstrated ∼88% protection when delivered 18 hours post-exposure for each of two administration routes (i.e., intraperitoneal and intranasal) in a dose-dependent manner. Our studies suggest that YPP-401 could provide an innovative, safe, and effective approach for managing Y. pestis infections, including those caused by naturally occurring or intentionally developed strains that cannot be managed by vaccines in development and antibiotics.

A New Method to Detect Variants of SARS-CoV-2 Using Reverse Transcription Loop-Mediated Isothermal Amplification Combined with a Bioluminescent Assay in Real Time (RT-LAMP-BART).

Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), of which there are several variants. The three major variants (Alpha, Delta, and Omicron) carry the N501Y, L452R, and Q493R/Q498R mutations, respectively, in the S gene. Control of COVID-19 requires rapid and reliable detection of not only SARS-CoV-2 but also its variants. We previously developed a reverse transcription loop-mediated isothermal amplification assay combined with a bioluminescent assay in real time (RT-LAMP-BART) to detect the L452R mutation in the SARS-CoV-2 spike protein. In this study, we established LAMP primers and peptide nucleic acid probes to detect N501Y and Q493R/Q498R. The LAMP primer sets and PNA probes were designed for the N501Y and Q493R/Q498R mutations on the S gene of SARS-CoV-2. The specificities of RT-LAMP-BART assays were evaluated using five viral and four bacterial reference strains. The sensitivities of RT-LAMP-BART assays were evaluated using synthetic RNAs that included the target sequences, together with RNA-spiked clinical nasopharyngeal and salivary specimens. The results were compared with those of conventional real-time reverse transcription-polymerase chain reaction (RT-PCR) methods. The method correctly identified N501Y and Q493R/Q498R. Within 30 min, the RT-LAMP-BART assays detected up to 100-200 copies of the target genes; conventional real-time RT-PCR required 130 min and detected up to 500-3000 copies. Surprisingly, the real-time RT-PCR for N501Y did not detect the BA.1 and BA.2 variants (Omicron) that exhibited the N501Y mutation. The novel RT-LAMP-BART assay is highly specific and more sensitive than conventional real-time RT-PCR. The new assay is simple, inexpensive, and rapid; thus, it can be useful in efforts to identify SARS-CoV-2 variants of concern.

Pandemic response gaps: Infection prevention and control lessons learned during coronavirus disease 2019 (COVID-19) outbreaks in skilled nursing facilities in Detroit, Michigan.

BACKGROUND: Hospitalizations among skilled nursing facility (SNF) residents in Detroit increased in mid-March 2020 due to the coronavirus disease 2019 (COVID-19) pandemic. Outbreak response teams were deployed from local healthcare systems, the Centers for Disease Control and Prevention (CDC), and the Detroit Health Department (DHD) to understand the infection prevention and control (IPC) gaps in SNFs that may have accelerated the outbreak. METHODS: We conducted 2 point-prevalence surveys (PPS-1 and PPS-2) at 13 Detroit SNFs from April 8 to May 8, 2020. The DHD and partners conducted facility-wide severe acute respiratory coronavirus virus 2 (SARS-CoV-2) testing of all residents and staff and collected information regarding resident cohorting, staff cohorting, and personnel protective equipment (PPE) utilized during that time. RESULTS: Resident cohorting had been implemented in 7 of 13 (58.3%) SNFs prior to point-prevalence survey 1 (PPS-1), and other facilities initiated cohorting after obtaining PPS-1 results. Cohorting protocols of healthcare practitioners and environmental service staff were not established in 4 (31%) of 13 facilities, and in 3 facilities (23.1%) the ancillary staff were not assigned to cohorts. Also, 2 SNFs (15%) had an observation unit prior to PPS-1, 2 (15%) had an observation unit after PPS-1, 4 (31%) could not establish an observation unit due to inadequate space, and 5 (38.4%) created an observation unit after PPS-2. CONCLUSION: On-site consultations identified gaps in IPC knowledge and cohorting that may have contributed to ongoing transmission of SARS-CoV-2 among SNF residents despite aggressive testing measures. Infection preventionists (IPs) are critical in guiding ongoing IPC practices in SNFs to reduce spread of COVID-19 through response and prevention.

A Bacteriophage-Based, Highly Efficacious, Needle- and Adjuvant-Free, Mucosal COVID-19 Vaccine.

The U.S. Food and Drug Administration-authorized mRNA- and adenovirus-based SARS-CoV-2 vaccines are intramuscularly injected in two doses and effective in preventing COVID-19, but they do not induce efficient mucosal immunity or prevent viral transmission. Here, we report the first noninfectious, bacteriophage T4-based, multicomponent, needle- and adjuvant-free, mucosal vaccine harboring engineered Spike trimers on capsid exterior and nucleocapsid protein in the interior. Intranasal administration of two doses of this T4 SARS-CoV-2 vaccine 21 days apart induced robust mucosal immunity, in addition to strong systemic humoral and cellular immune responses. The intranasal vaccine induced broad virus neutralization antibody titers against multiple variants, Th1-biased cytokine responses, strong CD4+ and CD8+ T cell immunity, and high secretory IgA titers in sera and bronchoalveolar lavage specimens from vaccinated mice. All of these responses were much stronger in intranasally vaccinated mice than those induced by the injected vaccine. Furthermore, the nasal vaccine provided complete protection and sterilizing immunity against the mouse-adapted SARS-CoV-2 MA10 strain, the ancestral WA-1/2020 strain, and the most lethal Delta variant in both BALB/c and human angiotensin converting enzyme (hACE2) knock-in transgenic mouse models. In addition, the vaccine elicited virus-neutralizing antibodies against SARS-CoV-2 variants in bronchoalveolar lavage specimens, did not affect the gut microbiota, exhibited minimal lung lesions in vaccinated and challenged mice, and is completely stable at ambient temperature. This modular, needle-free, phage T4 mucosal vaccine delivery platform is therefore an excellent candidate for designing efficacious mucosal vaccines against other respiratory infections and for emergency preparedness against emerging epidemic and pandemic pathogens. IMPORTANCE According to the World Health Organization, COVID-19 may have caused ~15-million deaths across the globe and is still ravaging the world. Another wave of ~100 million infections is predicted in the United States due to the emergence of highly transmissible immune-escaped Omicron variants. The authorized vaccines would not prevent these transmissions since they do not trigger mucosal immunity. We circumvented this limitation by developing a needle-free, bacteriophage T4-based, mucosal vaccine. This intranasally administered vaccine generates superior mucosal immunity in mice, in addition to inducing robust humoral and cell-mediated immune responses, and provides complete protection and sterilizing immunity against SARS-CoV-2 variants. The vaccine is stable, adjuvant-free, and cost-effectively manufactured and distributed, making it a strategically important next-generation COVID vaccine for ending this pandemic.

Corrigendum: Molecular Serotype-Specific Identification of Non-type b Haemophilus influenzae by Loop-Mediated Isothermal Amplification.

[This corrects the article DOI: 10.3389/fmicb.2017.01877.].

Detection of SARS-CoV-2 and the L452R spike mutation using reverse transcription loop-mediated isothermal amplification plus bioluminescent assay in real-time (RT-LAMP-BART).

The new coronavirus infection (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can be fatal, and several variants of SARS-CoV-2 with mutations of the receptor-binding domain (RBD) have increased avidity for human cell receptors. A single missense mutation of U to G at nucleotide position 1355 (U1355G) in the spike (S) gene changes leucine to arginine (L452R) in the spike protein. This mutation has been observed in the India and California strains (B.1.617 and B.1.427/B.1.429, respectively). Control of COVID-19 requires rapid and reliable detection of SARS-CoV-2. Therefore, we established a reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay plus a bioluminescent assay in real-time (BART) to detect SARS-CoV-2 and the L452R spike mutation. The specificity and sensitivity of the RT-LAMP-BART assay was evaluated using synthetic RNAs including target sequences and RNA-spiked clinical nasopharyngeal and saliva specimens as well as reference strains representing five viral and four bacterial pathogens. The novel RT-LAMP-BART assay to detect SARS-CoV-2 was highly specific compared to the conventional real-time RT-PCR. Within 25 min, the RT-LAMP-BART assay detected 80 copies of the target gene in a sample, whereas the conventional real-time RT-PCR method detected 5 copies per reaction within 130 min. Using RNA-spiked specimens, the sensitivity of the RT-LAMP-BART assay was slightly attenuated compared to purified RNA as a template. The results were identical to those of the conventional real-time RT-PCR method. Furthermore, using a peptide nucleic acid (PNA) probe, the RT-LAMP-BART method correctly identified the L452R spike mutation. This is the first report describes RT-LAMP-BART as a simple, inexpensive, rapid, and useful assay for detection of SARS-CoV-2, its variants of concern, and for screening of COVID-19.

Antibiotic Knowledge, Beliefs, and Behaviors: Testing Competing Hypotheses Using an Urban Community Sample.

Antibiotic use and misuse continue to be a worldwide concern with the increasing rate of antimicrobial resistance, lack of new antibiotics in the pipeline, and rising health care costs. Despite studies that attempt to distinguish between factors associated with antibiotic use and misuse (e.g., knowledge and beliefs and provider-patient communication), few studies have tested comparative hypotheses related to antibiotic use behavior. This study 1) compares two theoretical models (health belief and patient-centered communication) to learn which best represents the pathways associated with antibiotic use; and 2) describes urban consumers' knowledge, beliefs, and behaviors regarding antibiotic use. Interviewers completed 505 intercept surveys across six clinic- and community-based sites in Southeast Michigan. Structural equation modeling was utilized to compare two competing theoretical models predicting antibiotic behavior. Findings support the assertion that a patient-provider communication model fits the data better than the null model. Descriptive statistical analysis explicated participant knowledge was mixed. While many participants knew correct general facts about antibiotics, 35% of the sample put forth that they believed that antibiotics cure colds and flu and over half (57%) endorsed the belief that antibiotics are good for treating infections caused by viruses. The implications for theory and practice are discussed including the need for clinicians to target communication strategies for the populations that they serve.

Safety and tolerability of hydroxychloroquine in health care workers and first responders for the prevention of COVID-19: WHIP COVID-19 Study.

BACKGROUND: Health care workers (HCW) are among the highest risk groups for acquisition of COVID-19 because of occupational exposures. The WHIP COVID-19 Study aimed to evaluate the safety and efficacy of hydroxychloroquine (HCQ) as chemoprophylaxis for SARS-CoV-2 infection in this population. METHODS: HCW, first responders, and other occupationally high-risk participants were enrolled in a randomized, placebo-controlled clinical study of HCQ from April to October 2020. The trial compared daily versus weekly HCQ with placebo and with a prospective cohort on HCQ for autoimmune diseases. Participants were followed for 8 weeks. Serology or a positive polymerase chain reaction test was used to determine laboratory confirmed clinical cases. RESULTS: A total of 624 participants were randomized to placebo (n = 200), weekly HCQ (n = 201), daily HCQ (n = 197). For the primary safety end point, 279 (44.7%) participants experienced adverse event (AE) level II or lower (total AEs n = 589), similar rates in all randomized groups (P = .188) with no hospitalizations or interventions required. Only 4 laboratory confirmed COVID-19 cases occurred, with 2 in the placebo arm and one in each HCQ randomized arm. CONCLUSIONS: This randomized placebo-controlled trial was able to demonstrate the safety of HCQ outpatient chemoprophylaxis in high-risk groups against COVID-19. Future studies of chemoprophylaxis for SARS-CoV-2 are needed as the epidemic continues worldwide.

Development of a novel loop-mediated isothermal amplification assay for ß-lactamase gene identification using clinical isolates of Gram-negative bacteria.

Rapid evaluation of antimicrobial susceptibility is important in the treatment of nosocomial infections by Gram-negative bacteria, which increasingly carry carbapenemases and metallo-ß-lactamases. We developed loop-mediated isothermal amplification (LAMP)-based assays for four ß-lactamase genes (bla KPC, bla NDM-1, bla IMP-1 group, and bla VIM). The assays were evaluated using eight reference bacterial strains (Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, and Acinetobacter bereziniae) harboring six ß-lactamase genes. A total of 55 Gram-negative bacterial strains, including 47 clinical P. aeruginosa isolates, fully characterized by next-generation sequencing (NGS), were used to evaluate the LAMP assays. The results were compared to those of conventional PCR. The LAMP assays were able to detect as few as 10 to 100 copies of a gene, compared to 10 to 104 copies for conventional PCR. The LAMP assay detected four ß-lactamase genes with a sensitivity similar to that using purified DNA as the template in DNA-spiked urine, sputum, and blood specimens. By contrast, the sensitivity of PCR was 1- to 100-fold lower with DNA-spiked clinical specimens. Therefore, the LAMP assays were proved to be an appropriate tool for the detection of four ß-lactamases.

Combinatorial Viral Vector-Based and Live Attenuated Vaccines without an Adjuvant to Generate Broader Immune Responses to Effectively Combat Pneumonic Plague.

Mice immunized with a combination of an adenovirus vector (Ad5-YFV) and live-attenuated (LMA)-based vaccines were evaluated for protective efficacy against pneumonic plague. While the Ad5-YFV vaccine harbors a fusion cassette of three genes encoding YscF, F1, and LcrV, LMA represents a mutant of parental Yersinia pestis CO92 deleted for genes encoding Lpp, MsbB, and Ail. Ad5-YFV and LMA were either administered simultaneously (1-dose regimen) or 21 days apart in various orders and route of administration combinations (2-dose regimen). The 2-dose regimen induced robust immune responses to provide full protection to animals against parental CO92 and its isogenic F1 deletion mutant (CAF-) challenges during both short- and long-term studies. Mice intranasally (i.n.) immunized with Ad5-YFV first followed by LMA (i.n. or intramuscularly [i.m.]) had higher T- and B-cell proliferative responses and LcrV antibody titers than those in mice vaccinated with LMA (i.n. or i.m.) first ahead of Ad5-YFV (i.n.) during the long-term study. Specifically, the needle- and adjuvant-free vaccine combination (i.n.) is ideal for use in plague regions of endemicity. Conversely, with a 1-dose regimen, mice vaccinated with Ad5-YFV i.n. and LMA by the i.m. route provided complete protection to animals against CO92 and its CAF- mutant challenges and elicited Th1/Th2, as well as Th17 responses, making it suitable for emergency vaccination during a plague outbreak or bioterrorist attack. This is a first study in which a viral vector-based and live-attenuated vaccines were effectively used in combination, representing adjuvant- and/or needle-free immunization, with each vaccine triggering a distinct cellular immune response. IMPORTANCE Yersinia pestis, the causative agent of plague, is a Tier-1 select agent and a reemerging human pathogen. A 2017 outbreak in Madagascar with >75% of cases being pneumonic and 8.6% causalities emphasized the importance of the disease. The World Health Organization has indicated an urgent need to develop new-generation subunit and live-attenuated plague vaccines. We have developed a subunit vaccine, including three components (YscF, F1, and LcrV) using an adenovirus platform (Ad5-YFV). In addition, we have deleted virulence genes of Y. pestis (e.g., lpp, msbB, and ail) to develop a live-attenuated vaccine (LMA). Both of these vaccines generated robust humoral and cellular immunity and were highly efficacious in several animal models. We hypothesized the use of a heterologous prime-boost strategy or administrating both vaccines simultaneously could provide an adjuvant- and/or a needle-free vaccine(s) that has attributes of both vaccines for use in regions of endemicity and during an emergency situation.

A universal bacteriophage T4 nanoparticle platform to design multiplex SARS-CoV-2 vaccine candidates by CRISPR engineering.

A "universal" platform that can rapidly generate multiplex vaccine candidates is critically needed to control pandemics. Using the severe acute respiratory syndrome coronavirus 2 as a model, we have developed such a platform by CRISPR engineering of bacteriophage T4. A pipeline of vaccine candidates was engineered by incorporating various viral components into appropriate compartments of phage nanoparticle structure. These include expressible spike genes in genome, spike and envelope epitopes as surface decorations, and nucleocapsid proteins in packaged core. Phage decorated with spike trimers was found to be the most potent vaccine candidate in animal models. Without any adjuvant, this vaccine stimulated robust immune responses, both T helper cell 1 (TH1) and TH2 immunoglobulin G subclasses, blocked virus-receptor interactions, neutralized viral infection, and conferred complete protection against viral challenge. This new nanovaccine design framework might allow the rapid deployment of effective adjuvant-free phage-based vaccines against any emerging pathogen in the future.

23-valent polysaccharide vaccine (PPSV23)-targeted serotype-specific identification of Streptococcus pneumoniae using the loop-mediated isothermal amplification (LAMP) method.

Reports of invasive disease due to Streptococcus pneumoniae have declined since the introduction of pneumococcal conjugate vaccines (PCV7 and PCV13). The incidence of invasive diseases due to S. pneumoniae that are not addressed by the vaccines, however, has increased in children and adults, creating a global public health problem. Previously, we established the loop-mediated isothermal amplification (LAMP) method for a PCV13 serotype-specific assay. In the current study, we developed a rapid, simple, and cost-effective assay to detect serotypes in the 23-valent pneumococcal polysaccharide vaccine (PPSV23) using the LAMP method. In this study, LAMP primer sets for serotypes 2, 8, 9N, 10A, 11A, 12F, 15B, 17F, 20, 22F, and 33F of S. pneumoniae were developed. The reactivity, specificity, and sensitivity of LAMP assays were determined and compared to those of conventional PCR. The feasibility of LAMP assays in clinical application in patients with invasive pneumococcal diseases was validated by defining the detection limit of the LAMP assay with bacterial genomic DNA-spiked blood specimens. The specificity of each LAMP assay was determined using 44 serotypes of pneumococcal strains. Their sensitivity was 100 copies per reaction versus 103 to 106 copies per reaction for PCR assays. Using DNA-spiked blood specimens, excluding the LAMP assay that targeted serotype 22F (103 copies per reaction), the limit of detection of the LAMP assay was similar to that with purified DNA as the template (102 copies per reaction), compared with 103 to >106 copies per reaction for PCR assays. In conclusion, a rapid and simple LAMP-based PPSV23-targeted serotype detection assay was developed for use in many countries. This study is the first report of a LAMP-based assay for identification of PPSV23 serotypes. Further evaluation of this assay is needed through surveillance and vaccine efficacy studies.

A Universal Bacteriophage T4 Nanoparticle Platform to Design Multiplex SARS-CoV-2 Vaccine Candidates by CRISPR Engineering.

A "universal" vaccine design platform that can rapidly generate multiplex vaccine candidates is critically needed to control future pandemics. Here, using SARS-CoV-2 pandemic virus as a model, we have developed such a platform by CRISPR engineering of bacteriophage T4. A pipeline of vaccine candidates were engineered by incorporating various viral components into appropriate compartments of phage nanoparticle structure. These include: expressible spike genes in genome, spike and envelope epitopes as surface decorations, and nucleocapsid proteins in packaged core. Phage decorated with spike trimers is found to be the most potent vaccine candidate in mouse and rabbit models. Without any adjuvant, this vaccine stimulated robust immune responses, both T H 1 and T H 2 IgG subclasses, blocked virus-receptor interactions, neutralized viral infection, and conferred complete protection against viral challenge. This new type of nanovaccine design framework might allow rapid deployment of effective phage-based vaccines against any emerging pathogen in the future.

Antibiotics and antimicrobial resistance in the COVID-19 era: Perspective from resource-limited settings.

The dissemination of COVID-19 around the globe has been followed by an increased consumption of antibiotics. This is related to the concern for bacterial superinfection in COVID-19 patients. The identification of bacterial pathogens is challenging in low and middle income countries (LMIC), as there are no readily-available and cost-effective clinical or biological markers that can effectively discriminate between bacterial and viral infections. Fortunately, faced with the threat of COVID-19 spread, there has been a growing awareness of the importance of antimicrobial stewardship programs, as well as infection prevention and control measures that could help reduce the microbial load and hence circulation of pathogens, with a reduction in dissemination of antimicrobial resistance. These measures should be improved particularly in developing countries. Studies need to be conducted to evaluate the worldwide evolution of antimicrobial resistance during the COVID-19 pandemic, because pathogens do not respect borders. This issue takes on even greater importance in developing countries, where data on resistance patterns are scarce, conditions for infectious pathogen transmission are optimal, and treatment resources are suboptimal.

A new generation needle- and adjuvant-free trivalent plague vaccine utilizing adenovirus-5 nanoparticle platform.

A plague vaccine with a fusion cassette of YscF, F1, and LcrV encoding genes in an adenovirus-5 vector (rAd5-YFV) is evaluated for efficacy and immune responses in mice. Two doses of the vaccine provides 100% protection when administered intranasally against challenge with Yersinia pestis CO92 or its isogenic F1 mutant in short- or long- term immunization in pneumonic/bubonic plague models. The corresponding protection rates drop in rAd5-LcrV monovalent vaccinated mice in plague models. The rAd5-YFV vaccine induces superior humoral, mucosal and cell-mediated immunity, with clearance of the pathogen. Immunization of mice with rAd5-YFV followed by CO92 infection dampens proinflammatory cytokines and neutrophil chemoattractant production, while increasing Th1- and Th2-cytokine responses as well as macrophage/monocyte chemo-attractants when compared to the challenge control animals. This is a first study showing complete protection of mice from pneumonic/bubonic plague with a viral vector-based vaccine without the use of needles and the adjuvant.