SARS-CoV-2-specific immunoglobulin Y antibodies are protective in infected mice.

Safe, passive immunization methods are required against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and its variants. Immunization of chickens with antigen is known to induce specific IgY antibodies concentrated in the egg yolk and has a good safety profile, high yield of IgY per egg, can be topically applied, not requiring parenteral delivery. Our data provide the first evidence of the prophylactic efficacy of Immunoglobulin Y antibodies against SARS-CoV-2 in mice. Lohmann hens were injected with recombinant SARS-CoV-2 RBD protein; IgY-Abs were extracted from the eggs and characterized using SDS-PAGE. Antiviral activity was evaluated using plaque reduction neutralization tests. In additional experiments, IgY-RBD efficacy was examined in mice sensitized to SARS-CoV-2 infection by transduction with Ad5-hACE2 (mild disease) or by using mouse-adapted virus (severe disease). In both cases, prophylactic intranasal administration of IgY-Abs reduced SARS-CoV-2 replication, and reduced morbidity, inflammatory cell infiltration, hemorrhage, and edema in the lungs and increased survival compared to control groups that received non-specific IgY-Abs. These results indicate that further evaluation of IgY-RBD antibodies in humans is warranted.

Hepatitis B and Hepatitis C Infections among Female Inmates in a Prison in Jeddah, Saudi Arabia.

BACKGROUND: Hepatitis B virus (HBV) and hepatitis C virus (HCV) are major health concerns worldwide. Recent data indicate a decline in prevalence in the Saudi population; however, there are no data on the prevalence in prisoners. This study is the first to investigate the prevalence of viral hepatitis in female inmates in Jeddah, Saudi Arabia. This study aimed to explore the prevalence of HBV and HCV infections and to assess the knowledge and attitudes related to these infections among inmates. METHODS: Inmates were interviewed using a pre-designed questionnaire, and their blood samples were tested for HBV and HCV infections using serology, PCR, and phylogenetic analysis. RESULTS: The overall prevalence of HBV infection in the study population was 4.4%. The age group > 25 years was predominantly affected; 11.1% of the infected cases were Saudi nationals, and 88.9% were non-Saudis. The prevalence of HCV infection was 2.4%. Among the studied variables, age and previous employment were significantly associated with positive HBV PCR, while conviction, knowledge about protection from sexually transmitted infections (STIs), knowledge about condom use for protection against STIs, and condom use for protection against STIs were significantly associated with HCV infection. CONCLUSIONS: This study shows higher HBV and HCV prevalence in the female prisoners in Briman prison compared to the general population. Uneducated prisoners, over 25 years old, and convicted of prostitution are more associated with both HBV and HCV infection. Future preventive plans should include screening new prisoners with these risk factors for HBV and HCV at the time of entry.

A potential association between obesity and reduced effectiveness of COVID-19 vaccine-induced neutralizing humoral immunity.

Due to the adverse effects of obesity on host immunity, this study investigated the effectiveness of COVID-19 vaccines (BNT162b2, ChAdOx-nCov-2019, and mRNA-1273) in inducing anti-SARS-CoV-2 Spike (S) neutralizing antibodies among individuals with various obesity classes (class I, II, III, and super obesity). Sera from vaccinated obese individuals (n = 73) and normal BMI controls (n = 46) were subjected to S-based enzyme-linked immunosorbent assay (ELISA) and serum-neutralization test (SNT) to determine the prevalence and titer of anti-SARS-CoV-2 neutralizing antibodies. Nucleocapsid-ELISA was also utilized to distinguish between immunity acquired via vaccination only versus vaccination plus recovery from infection. Data were linked to participant demographics including age, gender, past COVID-19 diagnosis, and COVID-19 vaccination profile. S-based ELISA demonstrated high seroprevalence rates (>97%) in the study and control groups whether samples with evidence of past infection were included or excluded. Interestingly, however, SNT demonstrated a slightly significant reduction in both the rate and titer of anti-SARS-CoV-2 neutralizing antibodies among vaccinated obese individuals (60/73; 82.19%) compared to controls (45/46; 97.83%). The observed reduction in COVID-19 vaccine-induced neutralizing humoral immunity among obese individuals occurs independently of gender, recovery from past infection, and period from last vaccination. Our data suggest that COVID-19 vaccines are highly effective in inducing protective humoral immunity. This effectiveness, however, is potentially reduced among obese individuals which highlight the importance of booster doses to improve their neutralizing immunity. Further investigations on larger sample size remain necessary to comprehensively conclude about the effect of obesity on COVID-19 vaccine effectiveness on humoral immunity induction.

COVID-19 and other respiratory tract infections at mass gathering religious and sporting events.

PURPOSE OF REVIEW: Mass gathering (MG) religious events provide ideal conditions for transmission and globalization of respiratory tract infections (RTIs). We review recent literature on COVID-19 and other RTIs at recurring international annual MG religious and sporting events. RECENT FINDINGS: Due to the COVID-19 pandemic organizers of MG religious and sporting events introduced risk-based infection control measures that limited transmission of RTIs. The 2020 and 2021 Hajj were conducted with limited numbers of pilgrims compared to the annual millions of pilgrims. The Tokyo 2020 Olympic and Paralympic Games were cancelled and held in 2021. The success of the COVID-19 countermeasures at the 2021 Hajj and 2021 Tokyo Olympics was based on implementing good public health and social measures alongside a comprehensive testing strategy. SUMMARY: MG events are associated with transmission of a range of bacterial and viral RTIs. Introducing risk based a multitude of public health interventions can reduce transmission of SARS-CoV-2 and other RTIs.

Discovery of Bispecific Lead Compounds from Azadirachta indica against ZIKA NS2B-NS3 Protease and NS5 RNA Dependent RNA Polymerase Using Molecular Simulations.

Zika virus (ZIKV) has been characterized as one of many potential pathogens and placed under future epidemic outbreaks by the WHO. However, a lack of potential therapeutics can result in an uncontrolled pandemic as with other human pandemic viruses. Therefore, prioritized effective therapeutics development has been recommended against ZIKV. In this context, the present study adopted a strategy to explore the lead compounds from Azadirachta indica against ZIKV via concurrent inhibition of the NS2B-NS3 protease (ZIKVpro) and NS5 RNA dependent RNA polymerase (ZIKVRdRp) proteins using molecular simulations. Initially, structure-based virtual screening of 44 bioflavonoids reported in Azadirachta indica against the crystal structures of targeted ZIKV proteins resulted in the identification of the top four common bioflavonoids, viz. Rutin, Nicotiflorin, Isoquercitrin, and Hyperoside. These compounds showed substantial docking energy (-7.9 to -11.01 kcal/mol) and intermolecular interactions with essential residues of ZIKVpro (B:His51, B:Asp75, and B:Ser135) and ZIKVRdRp (Asp540, Ile799, and Asp665) by comparison to the reference compounds, O7N inhibitor (ZIKVpro) and Sofosbuvir inhibitor (ZIKVRdRp). Besides, long interval molecular dynamics simulation (500 ns) on the selected docked poses reveals stability of the respective docked poses contributed by intermolecular hydrogen bonds and hydrophobic interactions. The predicted complex stability was further supported by calculated end-point binding free energy using molecular mechanics generalized born surface area (MM/GBSA) method. Consequently, the identified common bioflavonoids are recommended as promising therapeutic inhibitors of ZIKVpro and ZIKVRdRp against ZIKV for further experimental assessment.

Virtual screening and molecular dynamics simulation analysis of Forsythoside A as a plant-derived inhibitor of SARS-CoV-2 3CLpro.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is a more severe strain of coronavirus (CoV) that was first emerged in China in 2019. Available antiviral drugs could be repurposed and natural compounds with antiviral activity could be safer and cheaper source of medicine for SARS-CoV-2. 78 natural antiviral compounds database was identified from literature and virtual screening technique was applied to identify potential 3-chymotrypsin-like protease (3CLpro) inhibitors. Molecular docking studies were conducted to analyze the main protease (3CLpro) and inhibitors interactions with key residues of active site of target protein (PDB ID: 6LU7), active site constitute the part of active domain I and II of 3CLpro. 10 compounds with highest dock score were subjected to calculate ADMET parameters to figure out drug-likeness. Molecular dynamic (MD) simulation of the selected lead was performed by Amber simulation package to understand the conformational changes in docked complex. MD simulations analysis (RMSD, RMSF, Rg, BF, HBs, and SASA plots) of lead bounded with 3CLpro, hence revealed the important structural turns and twists during MD simulations from 0 to 100 ns. MM-PBSA/GBSA methods has also been applied for the estimation binding free energy (BFE) of the selected lead-complex. The present study has identified lead compound "Forsythoside A" an active extract of Forsythia suspense as SARS-CoV-2 3CLpro inhibitor that can block the viral replication and translation. Structural analysis of target protein and lead compound performed in this study could contribute to the development of potential drug against SARS-CoV-2 infection.

Longevity of Middle East Respiratory Syndrome Coronavirus Antibody Responses in Humans, Saudi Arabia.

Understanding the immune response to Middle East respiratory syndrome coronavirus (MERS-CoV) is crucial for disease prevention and vaccine development. We studied the antibody responses in 48 human MERS-CoV infection survivors who had variable disease severity in Saudi Arabia. MERS-CoV-specific neutralizing antibodies were detected for 6 years postinfection.

Amotosalen and ultraviolet A light treatment efficiently inactivates severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in human plasma.

BACKGROUND AND OBJECTIVES: During the ongoing pandemic of COVID-19, SARS-CoV-2 RNA was detected in plasma and platelet products from asymptomatic blood donors, raising concerns about potential risk of transfusion transmission, also in the context of the current therapeutic approach utilizing plasma from convalescent donors. The objective of this study was to assess the efficacy of amotosalen/UVA light treatment to inactivate SARS-CoV-2 in human plasma to reduce the risk of potential transmission through blood transfusion. METHODS: Pools of three whole-blood-derived human plasma units (630-650 ml) were inoculated with a clinical SARS-CoV-2 isolate. Spiked units were treated with amotosalen/UVA light (INTERCEPT Blood System™) to inactivate SARS-CoV-2. Infectious titres and genomic viral load were assessed by plaque assay and real-time quantitative PCR. Inactivated samples were subject to three successive passages on permissive tissue culture to exclude the presence of replication-competent viral particles. RESULTS: Inactivation of infectious viral particles in spiked plasma units below the limit of detection was achieved by amotosalen/UVA light treatment with a mean log reduction of >3·32 ± 0·2. Passaging of inactivated samples on permissive tissue showed no viral replication even after 9 days of incubation and three passages, confirming complete inactivation. The treatment also inhibited NAT detection by nucleic acid modification with a mean log reduction of 2·92 ± 0·87 PFU genomic equivalents. CONCLUSION: Amotosalen/UVA light treatment of SARS-CoV-2 spiked human plasma units efficiently and completely inactivated >3·32 ± 0·2 log of SARS-CoV-2 infectivity, showing that such treatment could minimize the risk of transfusion-related SARS-CoV-2 transmission.

Inactivation of Middle East respiratory syndrome-coronavirus in human plasma using amotosalen and ultraviolet A light.

BACKGROUND: Middle East respiratory syndrome-coronavirus (MERS-CoV) is a novel zoonotic pathogen. Although the potential for MERS-CoV transmission through blood transfusion is not clear, MERS-CoV was recognized as a pathogen of concern for the safety of the blood supply especially after its detection in whole blood, serum, and plasma of infected individuals. Here we investigated the efficacy of amotosalen and ultraviolet A light (UVA) to inactivate MERS-CoV in fresh-frozen plasma (FFP). STUDY DESIGN AND METHODS: Pooled FFP units were spiked with a recent clinical MERS-CoV isolate. Infectious and genomic viral titers were determined in plasma before and after inactivation with amotosalen/UVA treatment by plaque assay and reverse transcription-quantitative polymerase chain reaction, respectively. In addition, residual replicating or live virus after inactivation was examined by passaging in the permissive Vero E6 cells. RESULTS: The mean MERS-CoV infectious titer in pretreatment samples was 4.67 ± 0.25 log plaque-forming units (pfu)/mL, which was reduced to undetectable levels after inactivation with amotosalen/UVA demonstrating a mean log reduction of more than 4.67 ± 0.25 pfu/mL. Furthermore, inoculation of inactivated plasma on Vero E6 cells did not result in any cytopathic effect (CPE) even after 7 days of incubation and three consecutive passages, nor the detection of MERS RNA compared to pretreatment samples which showed complete CPE within 2 to 3 days postinoculation and log viral RNA titer ranging from 9.48 to 10.22 copies/mL in all three passages. CONCLUSION: Our data show that amotosalen/UVA treatment is a potent and effective way to inactivate MERS-CoV infectious particles in FFP to undetectable levels and to minimize the risk of any possible transfusion-related MERS-CoV transmission.

Evidence for camel-to-human transmission of MERS coronavirus.

We describe the isolation and sequencing of Middle East respiratory syndrome coronavirus (MERS-CoV) obtained from a dromedary camel and from a patient who died of laboratory-confirmed MERS-CoV infection after close contact with camels that had rhinorrhea. Nasal swabs collected from the patient and from one of his nine camels were positive for MERS-CoV RNA. In addition, MERS-CoV was isolated from the patient and the camel. The full genome sequences of the two isolates were identical. Serologic data indicated that MERS-CoV was circulating in the camels but not in the patient before the human infection occurred. These data suggest that this fatal case of human MERS-CoV infection was transmitted through close contact with an infected camel.

Phylogenetic characterization of circulating Dengue and Alkhumra Hemorrhagic Fever viruses in western Saudi Arabia and lack of evidence of Zika virus in the region: A retrospective study, 2010-2015.

Flaviviruses represent a global public health concern. They consist of ∼70 viruses with almost half of them causing human diseases with unspecified febrile illnesses. Cities in western Saudi Arabia are endemic for viruses (DENV) with sporadic infections due to Alkhumra hemorrhagic fever virus (AHFV). They also represent a major destination for travelers coming for annual religious pilgrimages (Hajj and Umrah) from all over the world. However, whether other flaviviruses are circulating is not known because of the limited number of surveillance studies. Here, we retrospectively screened 690 samples for flaviviruses in samples from patients with unexplained febrile illnesses between 2010 and 2015 in western Saudi Arabia using a pan-flaviviruses RT-PCR assay. Despite Zika virus RNA was not detected, this study confirms circulation and/or sporadic spread of DENV-2, DENV-3, and AHFV, higher prevalence of DENV-2, and a role for visitors from DENV endemic countries in DENV importation into the Kingdom. Further analysis also showed very low genetic diversity of AHFV confirming its slow microevolution. Accordingly, continuous and prospective surveillance for flaviviruses using such assay are warranted in Saudi Arabia which receives millions of Muslims annually to implement effective control measures in light of the global widespread and outbreaks of several flaviviruses.

Complete genome sequencing and phylogenetic analysis of dengue type 1 virus isolated from Jeddah, Saudi Arabia.

BACKGROUND: Dengue viruses (DENVs) are mosquito-borne viruses which can cause disease ranging from mild fever to severe dengue infection. These viruses are endemic in several tropical and subtropical regions. Multiple outbreaks of DENV serotypes 1, 2 and 3 (DENV-1, DENV-2 and DENV-3) have been reported from the western region in Saudi Arabia since 1994. Strains from at least two genotypes of DENV-1 (Asia and America/Africa genotypes) have been circulating in western Saudi Arabia until 2006. However, all previous studies reported from Saudi Arabia were based on partial sequencing data of the envelope (E) gene without any reports of full genome sequences for any DENV serotypes circulating in Saudi Arabia. FINDINGS: Here, we report the isolation and the first complete genome sequence of a DENV-1 strain (DENV-1-Jeddah-1-2011) isolated from a patient from Jeddah, Saudi Arabia in 2011. Whole genome sequence alignment and phylogenetic analysis showed high similarity between DENV-1-Jeddah-1-2011 strain and D1/H/IMTSSA/98/606 isolate (Asian genotype) reported from Djibouti in 1998. Further analysis of the full envelope gene revealed a close relationship between DENV-1-Jeddah-1-2011 strain and isolates reported between 2004-2006 from Jeddah as well as recent isolates from Somalia, suggesting the widespread of the Asian genotype in this region. CONCLUSIONS: These data suggest that strains belonging to the Asian genotype might have been introduced into Saudi Arabia long before 2004 most probably by African pilgrims and continued to circulate in western Saudi Arabia at least until 2011. Most importantly, these results indicate that pilgrims from dengue endemic regions can play an important role in the spread of new DENVs in Saudi Arabia and the rest of the world. Therefore, availability of complete genome sequences would serve as a reference for future epidemiological studies of DENV-1 viruses.

Development and characterization of three novel mouse monoclonal antibodies targeting spike protein S1 subunit of Middle East Respiratory Syndrome Corona Virus.

BACKGROUND: Middle East Respiratory Syndrome Coronavirus is a highly pathogenic virus that poses a significant threat to public health. OBJECTIVE: The purpose of this study is to develop and characterize novel mouse monoclonal antibodies targeting the spike protein S1 subunit of the Middle East Respiratory Syndrome Corona Virus (MERS-CoV). METHODS: In this study, three mouse monoclonal antibodies (mAbs) against MERS-CoV were generated and characterized using hybridoma technology. The mAbs were evaluated for their reactivity and neutralization activity. The mAbs were generated through hybridoma technology by the fusion of myeloma cells and spleen cells from MERS-CoV-S1 immunized mice. The resulting hybridomas were screened for antibody production using enzyme-linked immunosorbent assays (ELISA). RESULTS: ELISA results demonstrated that all three mAbs exhibited strong reactivity against the MERS-CoV S1-antigen. Similarly, dot-ELISA revealed their ability to specifically recognize viral components, indicating their potential for diagnostic applications. Under non-denaturing conditions, Western blot showed the mAbs to have robust reactivity against a specific band at 116 KDa, corresponding to a putative MERS-CoV S1-antigen. However, no reactive bands were observed under denaturing conditions, suggesting that the antibodies recognize conformational epitopes. The neutralization assay showed no in vitro reactivity against MERS-CoV. CONCLUSION: This study successfully generated three mouse monoclonal antibodies against MERS-CoV using hybridoma technology. The antibodies exhibited strong reactivity against MERS-CoV antigens using ELISA and dot ELISA assays. Taken together, these findings highlight the significance of these mAbs for potential use as valuable tools for MERS-CoV research and diagnosis (community and field-based surveillance and viral antigen detection).

Genetic diversity and molecular analysis of human influenza virus among pilgrims during Hajj.

The risk of transmission of respiratory tract infections is considerably enhanced at mass gathering (MG) religious events. Hajj is an annual Islamic MG event with approximately 3 million Muslim pilgrims from over 180 countries concentrated in Makkah, Saudi Arabia. This study aimed to investigate the genetic diversity of influenza viruses circulating among pilgrims during the Hajj pilgrimage. We performed a cross-sectional analytical study where nasopharyngeal swabs (NPs) from pilgrims with respiratory tract illnesses presenting to healthcare facilities during the 2019 Hajj were screened for influenza viruses. Influenza A subtypes and influenza B lineages were determined by multiplex RT-PCR for positive influenza samples. The phylogenetic analysis was carried out for the hemagglutination (HA) gene. Out of 185 nasopharyngeal samples, 54 were positive for the human influenza virus. Of these, 27 were influenza A H1N1 and 19 H3N2, 4 were untypable influenza A, and 4 were influenza B. Phylogenetic analysis revealed that the H1N1 and H3N2 strains differentiated into different and independent genetic groups and formed close clusters with selected strains of influenza viruses from various locations. To conclude, this study demonstrates a high genetic diversity of circulating influenza A subtypes among pilgrims during the Hajj Season. There is a need for further larger studies to investigate in-depth the genetic characteristics of influenza viruses and other respiratory viruses during Hajj seasons.

IgY antibodies: The promising potential to overcome antibiotic resistance.

Antibiotic resistant bacteria are a growing threat to global health security. Whilst the emergence of antimicrobial resistance (AMR) is a natural phenomenon, it is also driven by antibiotic exposure in health care, agriculture, and the environment. Antibiotic pressure and inappropriate use of antibiotics are important factors which drive resistance. Apart from their use to treat bacterial infections in humans, antibiotics also play an important role in animal husbandry. With limited antibiotic options, alternate strategies are required to overcome AMR. Passive immunization through oral, nasal and topical administration of egg yolk-derived IgY antibodies from immunized chickens were recently shown to be effective for treating bacterial infections in animals and humans. Immunization of chickens with specific antigens offers the possibility of creating specific antibodies targeting a wide range of antibiotic-resistant bacteria. In this review, we describe the growing global problem of antimicrobial resistance and highlight the promising potential of the use of egg yolk IgY antibodies for the treatment of bacterial infections, particularly those listed in the World Health Organization priority list.

Computational Design and Experimental Evaluation of MERS-CoV siRNAs in Selected Cell Lines.

Middle East respiratory syndrome coronavirus (MERS-CoV) is caused by a well-known coronavirus first identified in a hospitalized patient in the Kingdom of Saudi Arabia. MERS-CoV is a serious pathogen affecting both human and camel health globally, with camels being known carriers of viruses that spread to humans. In this work, MERS-CoV genomic sequences were retrieved and analyzed by multiple sequence alignment to design and predict siRNAs with online software. The siRNAs were designed from the orf1ab region of the virus genome because of its high sequence conservation and vital role in virus replication. The designed siRNAs were used for experimental evaluation in selected cell lines: Vero cells, HEK-293-T, and Huh-7. Virus inhibition was assessed according to the cycle threshold value during a quantitative real-time polymerase chain reaction. Out of 462 potential siRNAs, we filtered out 21 based on specific selection criteria without off-target effect. The selected siRNAs did not show any cellular toxicity in the tested cell lines at various concentrations. Based on our results, it was obvious that the combined use of siRNAs exhibited a reduction in MERS-CoV replication in the Vero, HEK-293-T, and Huh-7 cell lines, with the highest efficacy displayed in the Vero cells.

Middle East respiratory syndrome coronavirus-a 10-year (2012-2022) global analysis of human and camel infections, genomic sequences, lineages, and geographical origins.

OBJECTIVES: The World Health Organization priority zoonotic pathogen Middle East respiratory syndrome (MERS) coronavirus (CoV) has a high case fatality rate in humans and circulates in camels worldwide. METHODS: We performed a global analysis of human and camel MERS-CoV infections, epidemiology, genomic sequences, clades, lineages, and geographical origins for the period January 1, 2012 to August 3, 2022. MERS-CoV Surface gene sequences (4061 bp) were extracted from GenBank, and a phylogenetic maximum likelihood tree was constructed. RESULTS: As of August 2022, 2591 human MERS cases from 26 countries were reported to the World Health Organization (Saudi Arabia, 2184 cases, including 813 deaths [case fatality rate: 37.2%]) Although declining in numbers, MERS cases continue to be reported from the Middle East. A total of 728 MERS-CoV genomes were identified (the largest numbers were from Saudi Arabia [222: human = 146, camels = 76] and the United Arab Emirates [176: human = 21, camels = 155]). A total of 501 'S'-gene sequences were used for phylogenetic tree construction (camels [n = 264], humans [n = 226], bats [n = 8], other [n=3]). Three MERS-CoV clades were identified: clade B, which is the largest, followed by clade A and clade C. Of the 462 clade B lineages, lineage 5 was predominant (n = 177). CONCLUSION: MERS-CoV remains a threat to global health security. MERS-CoV variants continue circulating in humans and camels. The recombination rates indicate co-infections with different MERS-CoV lineages. Proactive surveillance of MERS-CoV infections and variants of concern in camels and humans worldwide, and development of a MERS vaccine, are essential for epidemic preparedness.

Lack of Evidence on Association between Iron Deficiency and COVID-19 Vaccine-Induced Neutralizing Humoral Immunity.

Iron is a crucial micronutrient for immunity induction in response to infections and vaccinations. This study aimed to investigate the effect of iron deficiency on COVID-19-vaccine-induced humoral immunity. We investigated the effectiveness of COVID-19 vaccines (BNT162b2, mRNA-1273, and ChAdOx nCov-2019) in iron-deficient individuals (n = 63) and provide a side-by-side comparison to healthy controls (n = 67). The presence of anti-SARS-CoV-2 spike (S) and anti-nucleocapsid (NP) IgG were assessed using in-house S- and NP-based ELISA followed by serum neutralization test (SNT). High concordance between S-based ELISA and SNT results was observed. The prevalence of neutralizing antibodies was 95.24% (60/63) in the study group and 95.52% (64/67) in the controls with no significant difference. The presence/absence of past infection, period since vaccination, vaccine type, and being iron-deficient or having iron-deficiency anemia did not exert any significant effect on the prevalence or titer of anti-SARS-CoV-2 neutralizing antibodies. NP-based ELISA identified individuals unaware of exposure to SARS-CoV-2. Moreover, absence of anti-NP IgG was noted in participants who were previously diagnosed with COVID-19 suggesting the unpredictability of after-infection immunity. To sum up, this study demonstrated an initial lack of evidence on the association between iron deficiency and the effectiveness of COVID-19-vaccine-induced neutralizing humoral immunity. Similar studies with larger sample size remain necessary to obtain comprehensive conclusions about the effect or lack of effect of iron on COVID-19-vaccine effectiveness.

Hepatitis E Virus (HEV) in Makkah, Saudi Arabia: A Population-Based Seroprevalence Study.

BACKGROUND: The Hepatitis E virus (HEV) is a common cause of viral hepatitis worldwide. Little is known about the seroprevalence of HEV in the general population of Saudi Arabia. METHODS: A community-based cross-sectional HEV seroprevalence study was conducted in Makkah, Saudi Arabia. Anti-HEV IgG antibodies were detected in sera using an in-house ELISA. The frequency of HEV sageerology and its correlation with demographic, and environmental factors were evaluated. RESULTS: Enrollment consisted of 1329 individuals, ages ranged from 8 to 88 years, the mean age was 30.17 years, the median age was 28yrs, and the male: female ratio was 1.15. The overall seroprevalence was 23.8% (316/1329). Males had significantly higher seroprevalence than females (66.1 vs. 33.9%; p < 0.001). Seroprevalence had significant correlations with age, occupation, and lack of regular water supply and housing conditions. CONCLUSIONS: This is the first HEV community-based seroprevalence study from Saudi Arabia. Results show that the HEV is endemic in Makkah and affects all age groups and occupations. HEV affects more males than females and those living in crowded accommodations without a regular supply of water. Further studies are required across all regions of Saudi Arabia to determine the country's seroprevalence of active or past infection using tests for HEV IgG, HEV IgM antibodies and/or HEV RNA and underlying determinants of transmission.

Analysis of the nasopharyngeal microbiome and respiratory pathogens in COVID-19 patients from Saudi Arabia.

BACKGROUND: Infection with SARS-CoV-2 may perturb normal microbiota, leading to secondary infections that can complicate the viral disease. The aim of this study was to probe the alteration of nasopharyngeal (NP) microbiota in the context of SARS-CoV-2 infection and obesity and to identify other respiratory pathogens among COVID-19 cases that may affect patients' health. METHODS: A total of 107 NP swabs, including 22 from control subjects and 85 from COVID-19 patients, were processed for 6S amplicon sequencing. The respiratory pathogens causing secondary infections were identified by RT-PCR assay, using a kit that contained specific primers and probes combinations to amplify 33 known respiratory pathogens. RESULTS: No significant (p > 0.05) difference was observed in the alpha and beta diversity analysis, but specific taxa differed significantly between the control and COVID-19 patient groups. Genera of Sphingomonas, Kurthia, Microbacterium, Methylobacterium, Brevibacillus, Bacillus, Acinetobacter, Lactococcus, and Haemophilus was significantly abundant (p < 0.05) in COVID-19 patients compared with a healthy control group. Staphylococcus was found in relatively high abundance (35.7 %) in the COVID-19 patient groups, mainly those treated with antibiotics. A relatively high percentage of Streptococcus was detected in COVID-19 patient groups with obesity or other comorbidities. Respiratory pathogens, including Staphylococcus aureus, Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, and Salmonella species, along with Pneumocystis jirovecii fungal species were detected by RT-PCR mainly in the COVID-19 patients. Klebsiella pneumoniae was commonly found in most of the samples from the control and COVID-19 patients. Four COVID-19 patients had viral coinfections with human adenovirus, human rhinovirus, enterovirus, and human parainfluenza virus 1. CONCLUSIONS: Overall, no substantial difference was observed in the predominant NP bacterial community, but specific taxa were significantly changed between the healthy control and COVID-19 patients. Comparatively, an increased number of respiratory pathogens were identified in COVID-19 patients, and NP colonization by K. pneumoniae was probably occurring in the local population.