A multinational Delphi consensus to end the COVID-19 public health threat.

Despite notable scientific and medical advances, broader political, socioeconomic and behavioural factors continue to undercut the response to the COVID-19 pandemic1,2. Here we convened, as part of this Delphi study, a diverse, multidisciplinary panel of 386 academic, health, non-governmental organization, government and other experts in COVID-19 response from 112 countries and territories to recommend specific actions to end this persistent global threat to public health. The panel developed a set of 41 consensus statements and 57 recommendations to governments, health systems, industry and other key stakeholders across six domains: communication; health systems; vaccination; prevention; treatment and care; and inequities. In the wake of nearly three years of fragmented global and national responses, it is instructive to note that three of the highest-ranked recommendations call for the adoption of whole-of-society and whole-of-government approaches1, while maintaining proven prevention measures using a vaccines-plus approach2 that employs a range of public health and financial support measures to complement vaccination. Other recommendations with at least 99% combined agreement advise governments and other stakeholders to improve communication, rebuild public trust and engage communities3 in the management of pandemic responses. The findings of the study, which have been further endorsed by 184 organizations globally, include points of unanimous agreement, as well as six recommendations with >5% disagreement, that provide health and social policy actions to address inadequacies in the pandemic response and help to bring this public health threat to an end.

Effect of mRNA Vaccine Boosters against SARS-CoV-2 Omicron Infection in Qatar.

BACKGROUND: Waning of vaccine protection against coronavirus disease 2019 (Covid-19) and the emergence of the omicron (or B.1.1.529) variant of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have led to expedited efforts to scale up booster vaccination. Protection conferred by booster doses of the BNT162b2 (Pfizer-BioNTech) and mRNA-1273 (Moderna) vaccines in Qatar, as compared with protection conferred by the two-dose primary series, is unclear. METHODS: We conducted two matched retrospective cohort studies to assess the effectiveness of booster vaccination, as compared with that of a two-dose primary series alone, against symptomatic SARS-CoV-2 infection and Covid-19-related hospitalization and death during a large wave of omicron infections from December 19, 2021, through January 26, 2022. The association of booster status with infection was estimated with the use of Cox proportional-hazards regression models. RESULTS: In a population of 2,239,193 persons who had received at least two doses of BNT162b2 or mRNA-1273 vaccine, those who had also received a booster were matched with persons who had not received a booster. Among the BNT162b2-vaccinated persons, the cumulative incidence of symptomatic omicron infection was 2.4% (95% confidence interval [CI], 2.3 to 2.5) in the booster cohort and 4.5% (95% CI, 4.3 to 4.6) in the nonbooster cohort after 35 days of follow-up. Booster effectiveness against symptomatic omicron infection, as compared with that of the primary series, was 49.4% (95% CI, 47.1 to 51.6). Booster effectiveness against Covid-19-related hospitalization and death due to omicron infection, as compared with the primary series, was 76.5% (95% CI, 55.9 to 87.5). BNT162b2 booster effectiveness against symptomatic infection with the delta (or B.1.617.2) variant, as compared with the primary series, was 86.1% (95% CI, 67.3 to 94.1). Among the mRNA-1273-vaccinated persons, the cumulative incidence of symptomatic omicron infection was 1.0% (95% CI, 0.9 to 1.2) in the booster cohort and 1.9% (95% CI, 1.8 to 2.1) in the nonbooster cohort after 35 days; booster effectiveness against symptomatic omicron infection, as compared with the primary series, was 47.3% (95% CI, 40.7 to 53.3). Few severe Covid-19 cases were noted in the mRNA-1273-vaccinated cohorts. CONCLUSIONS: The messenger RNA (mRNA) boosters were highly effective against symptomatic delta infection, but they were less effective against symptomatic omicron infection. However, with both variants, mRNA boosters led to strong protection against Covid-19-related hospitalization and death. (Funded by Weill Cornell Medicine-Qatar and others.).

Covid-19 Vaccine Protection among Children and Adolescents in Qatar.

BACKGROUND: The BNT162b2 vaccine against coronavirus disease 2019 (Covid-19) has been authorized for use in children 5 to 11 years of age and adolescents 12 to 17 years of age but in different antigen doses. METHODS: We assessed the real-world effectiveness of the BNT162b2 vaccine against infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) among children and adolescents in Qatar. To compare the incidence of SARS-CoV-2 infection in the national cohort of vaccinated participants with the incidence in the national cohort of unvaccinated participants, we conducted three matched, retrospective, target-trial, cohort studies - one assessing data obtained from children 5 to 11 years of age after the B.1.1.529 (omicron) variant became prevalent and two assessing data from adolescents 12 to 17 years of age before the emergence of the omicron variant (pre-omicron study) and after the omicron variant became prevalent. Associations were estimated with the use of Cox proportional-hazards regression models. RESULTS: Among children, the overall effectiveness of the 10-µg primary vaccine series against infection with the omicron variant was 25.7% (95% confidence interval [CI], 10.0 to 38.6). Effectiveness was highest (49.6%; 95% CI, 28.5 to 64.5) right after receipt of the second dose but waned rapidly thereafter and was negligible after 3 months. Effectiveness was 46.3% (95% CI, 21.5 to 63.3) among children 5 to 7 years of age and 16.6% (95% CI, -4.2 to 33.2) among those 8 to 11 years of age. Among adolescents, the overall effectiveness of the 30-µg primary vaccine series against infection with the omicron variant was 30.6% (95% CI, 26.9 to 34.1), but many adolescents had been vaccinated months earlier. Effectiveness waned over time since receipt of the second dose. Effectiveness was 35.6% (95% CI, 31.2 to 39.6) among adolescents 12 to 14 years of age and 20.9% (95% CI, 13.8 to 27.4) among those 15 to 17 years of age. In the pre-omicron study, the overall effectiveness of the 30-µg primary vaccine series against SARS-CoV-2 infection among adolescents was 87.6% (95% CI, 84.0 to 90.4) and waned relatively slowly after receipt of the second dose. CONCLUSIONS: Vaccination in children was associated with modest, rapidly waning protection against omicron infection. Vaccination in adolescents was associated with stronger, more durable protection, perhaps because of the larger antigen dose. (Funded by Weill Cornell Medicine-Qatar and others.).

Effects of Previous Infection and Vaccination on Symptomatic Omicron Infections.

BACKGROUND: The protection conferred by natural immunity, vaccination, and both against symptomatic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection with the BA.1 or BA.2 sublineages of the omicron (B.1.1.529) variant is unclear. METHODS: We conducted a national, matched, test-negative, case-control study in Qatar from December 23, 2021, through February 21, 2022, to evaluate the effectiveness of vaccination with BNT162b2 (Pfizer-BioNTech) or mRNA-1273 (Moderna), natural immunity due to previous infection with variants other than omicron, and hybrid immunity (previous infection and vaccination) against symptomatic omicron infection and against severe, critical, or fatal coronavirus disease 2019 (Covid-19). RESULTS: The effectiveness of previous infection alone against symptomatic BA.2 infection was 46.1% (95% confidence interval [CI], 39.5 to 51.9). The effectiveness of vaccination with two doses of BNT162b2 and no previous infection was negligible (-1.1%; 95% CI, -7.1 to 4.6), but nearly all persons had received their second dose more than 6 months earlier. The effectiveness of three doses of BNT162b2 and no previous infection was 52.2% (95% CI, 48.1 to 55.9). The effectiveness of previous infection and two doses of BNT162b2 was 55.1% (95% CI, 50.9 to 58.9), and the effectiveness of previous infection and three doses of BNT162b2 was 77.3% (95% CI, 72.4 to 81.4). Previous infection alone, BNT162b2 vaccination alone, and hybrid immunity all showed strong effectiveness (>70%) against severe, critical, or fatal Covid-19 due to BA.2 infection. Similar results were observed in analyses of effectiveness against BA.1 infection and of vaccination with mRNA-1273. CONCLUSIONS: No discernable differences in protection against symptomatic BA.1 and BA.2 infection were seen with previous infection, vaccination, and hybrid immunity. Vaccination enhanced protection among persons who had had a previous infection. Hybrid immunity resulting from previous infection and recent booster vaccination conferred the strongest protection. (Funded by Weill Cornell Medicine-Qatar and others.).

Waning of BNT162b2 Vaccine Protection against SARS-CoV-2 Infection in Qatar.

BACKGROUND: Waning of vaccine protection against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection or coronavirus disease 2019 (Covid-19) is a concern. The persistence of BNT162b2 (Pfizer-BioNTech) vaccine effectiveness against infection and disease in Qatar, where the B.1.351 (or beta) and B.1.617.2 (or delta) variants have dominated incidence and polymerase-chain-reaction testing is done on a mass scale, is unclear. METHODS: We used a matched test-negative, case-control study design to estimate vaccine effectiveness against any SARS-CoV-2 infection and against any severe, critical, or fatal case of Covid-19, from January 1 to September 5, 2021. RESULTS: Estimated BNT162b2 effectiveness against any SARS-CoV-2 infection was negligible in the first 2 weeks after the first dose. It increased to 36.8% (95% confidence interval [CI], 33.2 to 40.2) in the third week after the first dose and reached its peak at 77.5% (95% CI, 76.4 to 78.6) in the first month after the second dose. Effectiveness declined gradually thereafter, with the decline accelerating after the fourth month to reach approximately 20% in months 5 through 7 after the second dose. Effectiveness against symptomatic infection was higher than effectiveness against asymptomatic infection but waned similarly. Variant-specific effectiveness waned in the same pattern. Effectiveness against any severe, critical, or fatal case of Covid-19 increased rapidly to 66.1% (95% CI, 56.8 to 73.5) by the third week after the first dose and reached 96% or higher in the first 2 months after the second dose; effectiveness persisted at approximately this level for 6 months. CONCLUSIONS: BNT162b2-induced protection against SARS-CoV-2 infection appeared to wane rapidly following its peak after the second dose, but protection against hospitalization and death persisted at a robust level for 6 months after the second dose. (Funded by Weill Cornell Medicine-Qatar and others.).

Antibody-dependent enhancement (ADE) of SARS-CoV-2 in patients exposed to MERS-CoV and SARS-CoV-2 antigens.

This study evaluated the potential for antibody-dependent enhancement (ADE) in serum samples from patients exposed to Middle East respiratory syndrome coronavirus (MERS-CoV). Furthermore, we evaluated the effect of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination on ADE in individuals with a MERS infection history. We performed ADE assay in sera from MERS recovered and SARS-CoV-2-vaccinated individuals using BHK cells expressing FcgRIIa, SARS-CoV-2, and MERS-CoV pseudoviruses (PVs). Further, we analyzed the association of ADE to serum IgG levels and neutralization. Out of 16 MERS patients, nine demonstrated ADE against SARS-CoV-2 PV, however, none of the samples demonstrated ADE against MERS-CoV PV. Furthermore, out of the seven patients exposed to SARS-CoV-2 vaccination after MERS-CoV infection, only one patient (acutely infected with MERS-CoV) showed ADE for SARS-CoV-2 PV. Further analysis indicated that IgG1, IgG2, and IgG3 against SARS-CoV-2 S1 and RBD subunits, IgG1 and IgG2 against the MERS-CoV S1 subunit, and serum neutralizing activity were low in ADE-positive samples. In summary, samples from MERS-CoV-infected patients exhibited ADE against SARS-CoV-2 and was significantly associated with low levels of neutralizing antibodies. Subsequent exposure to SARS-CoV-2 vaccination resulted in diminished ADE activity while the PV neutralization assay demonstrated a broadly reactive antibody response in some patient samples.

SARS-CoV-2 infection triggers more potent antibody-dependent cellular cytotoxicity (ADCC) responses than mRNA-, vector-, and inactivated virus-based COVID-19 vaccines.

Neutralizing antibodies (NAbs) are elicited after infection and vaccination and have been well studied. However, their antibody-dependent cellular cytotoxicity (ADCC) functionality is still poorly characterized. Here, we investigated ADCC activity in convalescent sera from infected patients with wild-type (WT) severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) or omicron variant compared with three coronavirus disease 2019 (COVID-19) vaccine platforms and postvaccination breakthrough infection (BTI). We analyzed ADCC activity targeting SARS-CoV-2 spike (S) and nucleocapsid (N) proteins in convalescent sera following WT SARS-CoV-2-infection (n = 91), including symptomatic and asymptomatic infections, omicron-infection (n = 8), COVID-19 vaccination with messenger RNA- (mRNA)- (BNT162b2 or mRNA-1273, n = 77), adenovirus vector- (n = 41), and inactivated virus- (n = 46) based vaccines, as well as post-mRNA vaccination BTI caused by omicron (n = 28). Correlations between ADCC, binding, and NAb titers were reported. ADCC was elicited within the first month postinfection and -vaccination and remained detectable for ≥3 months. WT-infected symptomatic patients had higher S-specific ADCC levels than asymptomatic and vaccinated individuals. Also, no difference in N-specific ADCC activity was seen between symptomatic and asymptomatic patients, but the levels were higher than the inactivated vaccine. Notably, omicron infection showed reduced overall ADCC activity compared to WT SARS-CoV-2 infection. Although post-mRNA vaccination BTI elicited high levels of binding and NAbs, ADCC activity was significantly reduced. Also, there was no difference in ADCC levels across the four vaccines, although NAbs and binding antibody titers were significantly higher in mRNA-vaccinated individuals. All evaluated vaccine platforms are inferior in inducing ADCC compared to natural infection with WT SARS-CoV-2. The inactivated virus-based vaccine can induce N-specific ADCC activity, but its relevance to clinical outcomes requires further investigation. Our data suggest that ADCC could be used to estimate the extra-neutralization level against COVID-19 and provides evidence that vaccination should focus on other Fc-effector functions besides NAbs. Also, the decreased susceptibility of the omicron variant to ADCC offers valuable guidance for forthcoming efforts to identify the specific targets of antibodies facilitating ADCC.

Epidemiology of gonorrhoea: systematic review, meta-analyses, and meta-regressions, World Health Organization European Region, 1949 to 2021.

BackgroundEpidemiology of Neisseria gonorrhoeae (NG) infection remains inadequately understood.AimWe aimed to characterise NG epidemiology in Europe.MethodsWe used Cochrane and PRISMA guidelines to systematically review, report, synthesise and analyse NG prevalence data from 1949 to 30 September 2021. Random-effects meta-analyses estimated pooled prevalence. Meta-regression analyses investigated associations and sources of heterogeneity.ResultsThe 844 included publications yielded 1,573 prevalence measures. Pooled prevalence of current urogenital infection was 1.0% (95% CI: 0.7-1.2%) among general populations, 3.2% (95% CI: 1.8-4.8%) among female sex workers, 4.9% (95% CI: 4.2-5.6%) among sexually transmitted infection clinic attendees and 12.1% (95% CI: 8.8-15.8%) among symptomatic men. Among men who have sex with men, pooled prevalence was 0.9% (95% CI: 0.5-1.4%), 5.6% (95% CI: 3.6-8.1%), and 3.8% (95% CI: 2.5-5.4%), respectively, for current urogenital, anorectal or oropharyngeal infection. Current urogenital, anorectal or oropharyngeal infection was 1.45-fold (95% CI: 1.19-1.77%), 2.75-fold (95% CI: 1.89-4.02%) and 2.64-fold (95% CI: 1.77-3.93%) higher among men than women. Current urogenital infection declined 0.97-fold (95% CI: 0.96-0.98%) yearly, but anorectal and oropharyngeal infection increased (1.02-fold; 95% CI: 1.01-1.04% and 1.02-fold; 95% CI: 1.00-1.04%), respectively.ConclusionsNeisseria gonorrhoeae epidemiology in Europe has distinct and contrasting epidemiologies for vaginal sex transmission in heterosexual sex networks vs anal and oral sex transmission in MSM sexual networks. Increased transmission may facilitate drug-resistant strain emergence. Europe is far from achieving the World Health Organization target of 90% incidence reduction by 2030.

Estimating protection afforded by prior infection in preventing reinfection: Applying the test-negative study design.

The COVID-19 pandemic has highlighted the need to use infection testing databases to rapidly estimate effectiveness of prior infection in preventing reinfection ($P{E}_S$) by novel SARS-CoV-2 variants. Mathematical modeling was used to demonstrate a theoretical foundation for applicability of the test-negative, case-control study design to derive $P{E}_S$. Apart from the very early phase of an epidemic, the difference between the test-negative estimate for $P{E}_S$ and true value of $P{E}_S$ was minimal and became negligible as the epidemic progressed. The test-negative design provided robust estimation of $P{E}_S$ and its waning. Assuming that only 25% of prior infections are documented, misclassification of prior infection status underestimated $P{E}_S$, but the underestimate was considerable only when >50% of the population was ever infected. Misclassification of latent infection, misclassification of current active infection, and scale-up of vaccination all resulted in negligible bias in estimated $P{E}_S$. The test-negative design was applied to national-level testing data in Qatar to estimate $P{E}_S$ for SARS-CoV-2. $P{E}_S$ against SARS-CoV-2 Alpha and Beta variants was estimated at 97.0% (95% CI: 93.6-98.6) and 85.5% (95% CI: 82.4-88.1), respectively. These estimates were validated using a cohort study design. The test-negative design offers a feasible, robust method to estimate protection from prior infection in preventing reinfection.

Duration of effectiveness of vaccines against SARS-CoV-2 infection and COVID-19 disease: results of a systematic review and meta-regression.

BACKGROUND: Knowing whether COVID-19 vaccine effectiveness wanes is crucial for informing vaccine policy, such as the need for and timing of booster doses. We aimed to systematically review the evidence for the duration of protection of COVID-19 vaccines against various clinical outcomes, and to assess changes in the rates of breakthrough infection caused by the delta variant with increasing time since vaccination. METHODS: This study was designed as a systematic review and meta-regression. We did a systematic review of preprint and peer-reviewed published article databases from June 17, 2021, to Dec 2, 2021. Randomised controlled trials of COVID-19 vaccine efficacy and observational studies of COVID-19 vaccine effectiveness were eligible. Studies with vaccine efficacy or effectiveness estimates at discrete time intervals of people who had received full vaccination and that met predefined screening criteria underwent full-text review. We used random-effects meta-regression to estimate the average change in vaccine efficacy or effectiveness 1-6 months after full vaccination. FINDINGS: Of 13 744 studies screened, 310 underwent full-text review, and 18 studies were included (all studies were carried out before the omicron variant began to circulate widely). Risk of bias, established using the risk of bias 2 tool for randomised controlled trials or the risk of bias in non-randomised studies of interventions tool was low for three studies, moderate for eight studies, and serious for seven studies. We included 78 vaccine-specific vaccine efficacy or effectiveness evaluations (Pfizer-BioNTech-Comirnaty, n=38; Moderna-mRNA-1273, n=23; Janssen-Ad26.COV2.S, n=9; and AstraZeneca-Vaxzevria, n=8). On average, vaccine efficacy or effectiveness against SARS-CoV-2 infection decreased from 1 month to 6 months after full vaccination by 21·0 percentage points (95% CI 13·9-29·8) among people of all ages and 20·7 percentage points (10·2-36·6) among older people (as defined by each study, who were at least 50 years old). For symptomatic COVID-19 disease, vaccine efficacy or effectiveness decreased by 24·9 percentage points (95% CI 13·4-41·6) in people of all ages and 32·0 percentage points (11·0-69·0) in older people. For severe COVID-19 disease, vaccine efficacy or effectiveness decreased by 10·0 percentage points (95% CI 6·1-15·4) in people of all ages and 9·5 percentage points (5·7-14·6) in older people. Most (81%) vaccine efficacy or effectiveness estimates against severe disease remained greater than 70% over time. INTERPRETATION: COVID-19 vaccine efficacy or effectiveness against severe disease remained high, although it did decrease somewhat by 6 months after full vaccination. By contrast, vaccine efficacy or effectiveness against infection and symptomatic disease decreased approximately 20-30 percentage points by 6 months. The decrease in vaccine efficacy or effectiveness is likely caused by, at least in part, waning immunity, although an effect of bias cannot be ruled out. Evaluating vaccine efficacy or effectiveness beyond 6 months will be crucial for updating COVID-19 vaccine policy. FUNDING: Coalition for Epidemic Preparedness Innovations.

Epidemiology of herpes simplex virus type 2 in the Middle East and North Africa: Systematic review, meta-analyses, and meta-regressions.

Herpes simplex virus type 2 (HSV-2) infection is a prevalent, sexually transmitted infection with poorly characterized prevalence in the Middle East and North Africa (MENA) region. This study characterized HSV-2 epidemiology in MENA. HSV-2 reports were systematically reviewed as guided by the Cochrane Collaboration Handbook and findings were reported following PRISMA guidelines. Random-effects meta-analyses and meta-regressions were performed to estimate pooled mean outcome measures and to assess predictors of HSV-2 antibody prevalence (seroprevalence), trends in seroprevalence, and between-study heterogeneity. In total, sixty-one overall (133 stratified) HSV-2 seroprevalence measures and two overall (four stratified) proportion measures of HSV-2 detection in laboratory-confirmed genital herpes were extracted from 37 relevant publications. Pooled mean seroprevalence was 5.1% (95% confidence interval [CI]: 3.6%-6.8%) among general populations, 13.3% (95% CI: 8.6%-18.7%) among intermediate-risk populations, 20.6% (95% CI: 5.3%-42.3%) among female sex workers, and 18.3% (95% CI: 3.9%-39.4%) among male sex workers. Compared to Fertile Crescent countries, seroprevalence was 3.39-fold (95% CI: 1.86-6.20) and 3.90-fold (95% CI: 1.78-8.57) higher in Maghreb and Horn of Africa countries, respectively. Compared to studies published before 2010, seroprevalence was 1.73-fold (95% CI: 1.00-2.99) higher in studies published after 2015. Pooled mean proportion of HSV-2 detection in genital herpes was 73.8% (95% CI: 42.2%-95.9%). In conclusion, MENA has a lower HSV-2 seroprevalence than other world regions. Yet, 1 in 20 adults is chronically infected, despite conservative prevailing sexual norms. Seroprevalence may also be increasing, unlike other world regions. Findings support the need for expansion of surveillance and monitoring of HSV-2 infection in MENA.

Seroprevalence of herpes simplex virus type 1 and type 2 among the migrant workers in Qatar.

BACKGROUND: Limited data exists on herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) infections in migrant populations. This study investigated HSV-1 and HSV-2 seroprevalences and associations among craft and manual workers (CMWs) in Qatar who constitute 60% of Qatar's population. METHODS: A national population-based cross-sectional seroprevalence survey was conducted on the CMW population, all men, between July 26 and September 9, 2020. 2,612 sera were tested for anti-HSV-1 IgG antibodies using HerpeSelect 1 ELISA IgG kits and for anti-HSV-2 IgG antibodies using HerpeSelect 2 ELISA IgG kits (Focus Diagnostics, USA). Univariable and multivariable logistic regression analyses were conducted to identify associations with HSV-1 and HSV-2 infections. RESULTS: Serological testing identified 2,171 sera as positive, 403 as negative, and 38 as equivocal for HSV-1 antibodies, and 300 sera as positive, 2,250 as negative, and 62 as equivocal for HSV-2 antibodies. HSV-1 and HSV-2 seroprevalences among CMWs were estimated at 84.2% (95% CI 82.8-85.6%) and 11.4% (95% CI 10.1-12.6%), respectively. HSV-1 infection was associated with nationality, educational attainment, and occupation. HSV-2 infection was associated with age, nationality, and educational attainment. CONCLUSIONS: Over 80% of CMWs are infected with HSV-1 and over 10% are infected with HSV-2. The findings highlight the need for sexual health programs to tackle sexually transmitted infections among the CMW population.

A review of rapid food safety testing: using lateral flow assay platform to detect foodborne pathogens.

The detrimental impact of foodborne pathogens on human health makes food safety a major concern at all levels of production. Conventional methods to detect foodborne pathogens, such as live culture, high-performance liquid chromatography, and molecular techniques, are relatively tedious, time-consuming, laborious, and expensive, which hinders their use for on-site applications. Recurrent outbreaks of foodborne illness have heightened the demand for rapid and simple technologies for detection of foodborne pathogens. Recently, Lateral flow assays (LFA) have drawn attention because of their ability to detect pathogens rapidly, cheaply, and on-site. Here, we reviewed the latest developments in LFAs to detect various foodborne pathogens in food samples, giving special attention to how reporters and labels have improved LFA performance. We also discussed different approaches to improve LFA sensitivity and specificity. Most importantly, due to the lack of studies on LFAs for the detection of viral foodborne pathogens in food samples, we summarized our recent research on developing LFAs for the detection of viral foodborne pathogens. Finally, we highlighted the main challenges for further development of LFA platforms. In summary, with continuing improvements, LFAs may soon offer excellent performance at point-of-care that is competitive with laboratory techniques while retaining a rapid format.

Epidemiology of herpes simplex virus type 1 and genital herpes in Australia and New Zealand: systematic review, meta-analyses and meta-regressions.

Herpes simplex virus type 1 (HSV-1) infection is a lifelong infection that is acquired primarily orally and during childhood. We aimed to characterise HSV-1 epidemiology in Australia and New Zealand. HSV-1-related data as recent as 6 December 2021 were systematically reviewed, synthesised and reported, following PRISMA guidelines. Pooled mean seroprevalence and proportions of HSV-1 detection in genital ulcer disease (GUD) and in genital herpes were calculated using random-effects meta-analyses. Meta-regressions were also conducted. HSV-1 measures were retrieved from 21 eligible publications. Extracted HSV-1 measures included 13 overall seroprevalence measures (27 stratified) in Australia, four overall proportions of HSV-1 detection in clinically diagnosed GUD (four stratified) in Australia, and ten overall proportions of HSV-1 detection in laboratory-confirmed genital herpes (26 stratified) in Australia and New Zealand. Pooled mean seroprevalence among healthy adults in Australia was 84.8% (95% confidence interval (CI) 74.3-93.1%). Pooled mean seroprevalence was 70.2% (95% CI 47.4-88.7%) among individuals <35 years of age and 86.9% (95% CI 79.3-93.0%) among individuals ≥35 years. Seroprevalence increased by 1.05-fold (95% CI 1.01-1.10) per year. Pooled mean proportion of HSV-1 detection in GUD was 8.2% (95% CI 0.4-22.9%). Pooled mean proportion of HSV-1 detection in genital herpes was 30.5% (95% CI 23.3-38.3%), and was highest in young individuals. Proportion of HSV-1 detection in genital herpes increased by 1.04-fold (95% CI 1.00-1.08) per year. Included studies showed heterogeneity, but 30% of the heterogeneity in seroprevalence and 42% of the heterogeneity in proportion of HSV-1 detection in genital herpes were explained in terms of epidemiological factors. HSV-1 seroprevalence is higher in Australia than in other Western countries. HSV-1 epidemiology in Australia and New Zealand appears to be transitioning towards less oral acquisition in childhood, but more genital acquisition among youth.

Coronavirus Disease 2019 Disease Severity in Children Infected With the Omicron Variant.

SHORT SUMMARY: Severe acute respiratory syndrome coronavirus 2 infection from the Omicron variant in children/adolescents is less severe than infection from the Delta variant. Those 6 to <18 years also have less severe disease than those <6 years old. BACKGROUND: There are limited data assessing coronavirus 2019 (COVID-19) disease severity in children/adolescents infected with the Omicron variant. METHODS: We identified children and adolescents <18 years of age with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection with Delta and propensity score-matched controls with Omicron variant infection from the National COVID-19 Database in Qatar. Primary outcome was disease severity, determined by hospital admission, admission to the intensive care unit (ICU), or mechanical ventilation within 14 days of diagnosis, or death within 28 days. RESULTS: Among 1735 cases with Delta variant infection between 1 June and 6 November 2021, and 32 635 cases with Omicron variant infection between 1 January and 15 January 2022, who did not have prior infection and were not vaccinated, we identified 985 propensity score-matched pairs. Among those who were Delta infected, 84.2% had mild, 15.7% had moderate, and 0.1% had severe/critical disease. Among those who were Omicron infected, 97.8% had mild, 2.2% had moderate, and none had severe/critical disease (P < .001). Omicron variant infection (vs Delta) was associated with significantly lower odds of moderate or severe/critical disease (adjusted odds ratio [AOR], 0.12; 95% confidence interval [CI], .07-.18). Those aged 6-11 and 12 to <18 years had lower odds of developing moderate or severe/critical disease compared with those younger than age 6 years (aOR, 0.47; 95% CI, .33-.66 for 6-11 year olds; aOR, 0.45; 95% CI, .21-.94 for 12 to <18 year olds). CONCLUSIONS: Omicron variant infection in children/adolescents is associated with less severe disease than Delta variant infection as measured by hospitalization rates and need for ICU care or mechanical ventilation. Those 6 to <18 years of age also have less severe disease than those <6 years old.

Severity, Criticality, and Fatality of the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Beta Variant.

Beta (B.1.351)-variant coronavirus disease 2019 (COVID-19) disease was investigated in Qatar. Compared with the Alpha (B.1.1.7) variant, odds (95% confidence interval) of progressing to severe disease, critical disease, and COVID-19-related death were 1.24-fold (1.11-1.39), 1.49-fold (1.13-1.97), and 1.57-fold (1.03-2.43) higher, respectively, for the Beta variant.

Estimated economic burden of genital herpes and HIV attributable to herpes simplex virus type 2 infections in 90 low- and middle-income countries: A modeling study.

BACKGROUND: Economic losses due to herpes simplex infections in low- and middle-income countries (LMICs) are unknown. We estimated economic and quality-of-life losses due to genital herpes in 2019, in 90 LMICs, and from 2020 to 2030 in 45 countries in the World Health Organization (WHO) Africa. We additionally estimated economic losses due to human immunodeficiency virus (HIV) attributable to herpes simplex virus type 2 (HSV-2) infections. METHODS AND FINDINGS: We estimated genital herpes-related spending on treatment, wage losses due to absenteeism, and reductions in quality of life, for individuals aged 15 to 49 years, living with genital herpes. Had HSV-2 had contributed to the transmission of HIV, we estimated the share of antiretroviral treatment costs and HIV-related wage losses in 2019 that can be attributed to incident and prevalent HSV-2 infections in 2018. For the former, we used estimates of HSV-2 incidence and prevalence from the global burden of disease (GBD) study. For the latter, we calculated population attributable fractions (PAFs), using the classic (Levin's) epidemiological formula for polytomous exposures, with relative risks (RRs) reported in literature. To extend estimates from 2020 to 2030, we modeled the transmission of HSV-2 in 45 African countries using a deterministic compartmental mathematical model, structured by age, sex, and sexual activity, which was fitted to seroprevalence gathered from a systematic review and meta-regression analysis. In the 90 LMICs, genital herpes contributed to US$813.5 million in treatment and productivity losses in 2019 (range: US$674.4 to US$952.2 million). Given observed care-seeking and absenteeism, losses are in the range of US$29.0 billion (US$25.6 billion to US$34.5 billion). Quality-of-life losses in the amount of 61.7 million quality-adjusted life years (QALYs) are also possible (50.4 million to 74.2 million). The mean annual cost of treatment and wage losses per infection is US$183.00 (95% CI: US$153.60 to US$212.55); the mean annual cost of quality-of-life losses is US$343.27 (95% CI: 272.41 to 414.14). If HSV-2 has fueled the transmission of HIV, then seroprevalent HSV-2 cases in 2018 can account for 33.2% of the incident HIV infections in 2019, with an associated antiretroviral therapy (ART) cost of US$186.3 million (range: US$163.6 to US$209.5 million) and 28.6% of HIV-related wage losses (US$21.9 million; range: US$19.2 to US$27.4 million). In the WHO Africa region, the 3.9 million seroprevalent genital herpes cases from 2020 to 2030 contributed to US$700.2 million in treatment and productivity losses. Additionally, quality-of-life losses in the range of 88 million to 871 million QALYs are also possible. If HSV-2 has contributed to the transmission of HIV, then in 2020, the PAF of HIV due to prevalent HSV-2 will be 32.8% (95% CI: 26.7% to 29.9%) and due to incident infections will be 4.2% (95% CI: 2.6% to 3.4%). The PAF due to prevalent infections will decline to 31.0% by 2030 and incident infections to 3.6%. Though we have accounted for the uncertainty in the epidemiological and economic parameter values via the sensitivity analysis, our estimates still undervalue losses due to limiting to the 15- to 49-year-old population. CONCLUSIONS: Economic losses due to genital herpes in LMICs can be large, especially when considering the lifelong nature of the disease. Quality-of-life losses outweigh spending on treatment and reductions in productivity. If HSV-2 has contributed to the spread of HIV in LMICs, then nearly one third of antiretroviral costs and HIV-related wage losses can be attributed to HSV-2. Given the magnitude of the combined losses, a vaccine against HSV-2 must be a global priority.

Epidemiology of Herpes Simplex Virus Type 2 in Canada, Australia, and New Zealand: Systematic Review, Meta-Analyses, and Meta-Regressions.

BACKGROUND: This study characterized the epidemiology of herpes simplex virus type 2 (HSV-2) infection in Canada, Australia, and New Zealand. METHODS: Cochrane and PRISMA guidelines were followed to systematically review, synthesize, and report HSV-2-related data up to January 21, 2021. Meta-analyses and meta-regressions were performed. RESULTS: In Canada, pooled mean seroprevalence was 10.0% (95% confidence interval [CI], 7.8-12.4%) among general populations, 44.5% (95% CI, 20.0-70.5%) among sexually transmitted infection clinic attendees and symptomatic populations, and 60.7% (95% CI, 49.8-71.1%) among human immunodeficiency virus (HIV)-positive individuals and individuals in HIV-discordant couples. In Australia and New Zealand, combined, pooled mean seroprevalence was 15.4% (95% CI, 9.6-22.2%) among general populations, 27.8% (95% CI, 12.0-47.2%) among men who have sex with men, and 37.2% (95% CI, 23.7-51.8%) among sexually transmitted infection clinic attendees and symptomatic populations. Men had 0.64-fold (95% CI, 0.47-0.86) lower seroprevalence compared with women. No evidence was found for a decline in seroprevalence over time. Pooled mean proportion of HSV-2 isolation in laboratory-confirmed genital herpes was 62.1% (95% CI, 53.8-70.1%) in Canada and 71.9% (95% CI, 64.2-78.9%) in Australia and New Zealand. Proportion of HSV-2 isolation in genital herpes declined by 0.98-fold (95% CI, 0.97-0.99) per year. Pooled mean proportion of HSV-2 isolation in genital ulcer disease was 17.4% (95% CI, 4.0-37.1%) in these countries. CONCLUSIONS: Over 10% of adults in these countries are infected, with no evidence for declining seroprevalence, unlike other global regions. Over 60% of genital herpes cases are caused by HSV-2 in these countries, yet HSV-2's role is declining by 2% per year.

Low Risk of Serological Cross-Reactivity between the Dengue Virus and SARS-CoV-2-IgG Antibodies Using Advanced Detection Assays.

Several studies have reported serological cross-reactivity of the immune responses between SARS-CoV-2 and DENV. Most of the available studies are based on the point-of-care rapid testing kits. However, some rapid test kits have low specificity and can generate false positives. Hence, we aimed to investigate the potential serological cross-reactivity between SARS-CoV-2 and DENV-IgG antibodies using advanced assays including chemiluminescence immunoassay (CLIA) and enzyme-linked immunosorbent assay (ELISA) test. A total of 90 DENV-IgG-ELISA-positive and 90 DENV-IgG-ELISA-negative prepandemic sera were tested for anti-SARS-CoV-2-IgG using the automated CL-900i CLIA assay. Furthermore, a total of 91 SARS-CoV-2-IgG-CLIA-positive and 91 SARS-CoV-2-IgG-CLIA-negative postpandemic sera were tested for anti-DENV-IgG using the NovaLisa ELISA kit. The DENV-IgG-positive sera resulted in five positives and 85 negatives for SARS-CoV-2-IgG. Similarly, the DENV-IgG-negative sera also resulted in 5 positives and 85 negatives for SARS-CoV-2-IgG. No statistically significant difference in specificity between the DENV-IgG-positive and DENV-IgG-negative sera was found (p value = 1.00). The SARS-CoV-2-IgG-positive sera displayed 43 positives, 47 negatives, and 1 equivocal for DENV-IgG, whereas the SARS-CoV-2-IgG-negative sera resulted in 50 positives, 40 negatives, and 1 equivocal for DENV-IgG. No statistically significant difference in the proportion that is DENV-IgG positive between the SARS-CoV-2-IgG-positive and SARS-CoV-2-IgG-negative sera (p value = 0.58). In conclusion, there is a low risk of serological cross-reactivity between the DENV and SARS-CoV-2-IgG antibodies when using advanced detection assays.

Analyzing inherent biases in SARS-CoV-2 PCR and serological epidemiologic metrics.

BACKGROUND: Prospective observational data show that infected persons with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remain polymerase chain reaction (PCR) positive for a prolonged duration, and that detectable antibodies develop slowly with time. We aimed to analyze how these effects can bias key epidemiological metrics used to track and monitor SARS-CoV-2 epidemics. METHODS: An age-structured mathematical model was constructed to simulate progression of SARS-CoV-2 epidemics in populations. PCR testing to diagnose infection and cross-sectional surveys to measure seroprevalence were also simulated. Analyses were conducted on simulated outcomes assuming a natural epidemic time course and an epidemic in presence of interventions. RESULTS: The prolonged PCR positivity biased the epidemiological measures. There was a lag of 10 days between the true epidemic peak and the actually-observed peak. Prior to epidemic peak, PCR positivity rate was twofold higher than that based only on current active infection, and half of those tested positive by PCR were in the prolonged PCR positivity stage after infection clearance. Post epidemic peak, PCR positivity rate poorly predicted true trend in active infection. Meanwhile, the prolonged PCR positivity did not appreciably bias estimation of the basic reproduction number R0. The time delay in development of detectable antibodies biased measured seroprevalence. The actually-observed seroprevalence substantially underestimated true prevalence of ever infection, with the underestimation being most pronounced around epidemic peak. CONCLUSIONS: Caution is warranted in interpreting PCR and serological testing data, and any drawn inferences need to factor the effects of the investigated biases for an accurate assessment of epidemic dynamics.