Objectives: To summarise the evidence on the detection pattern and viral load of SARS-CoV-2 over the course of an infection (including any asymptomatic or pre-symptomatic phase), and the duration of infectivity. Methods: A systematic literature search was undertaken in PubMed, Europe PubMed Central and EMBASE from 30 December 2019 to 12 May 2020. Results: We identified 113 studies conducted in 17 countries. The evidence from upper respiratory tract samples suggests that the viral load of SARS-CoV-2 peaks around symptom onset or a few days thereafter, and becomes undetectable about two weeks after symptom onset; however, viral loads from sputum samples may be higher, peak later and persist for longer. There is evidence of prolonged virus detection in stool samples, with unclear clinical significance. No study was found that definitively measured the duration of infectivity; however, patients may not be infectious for the entire duration of virus detection, as the presence of viral ribonucleic acid may not represent transmissible live virus. Conclusion: There is a relatively consistent trajectory of SARS-CoV-2 viral load over the course of COVID-19 from respiratory tract samples, however the duration of infectivity remains uncertain.

Summary In this review, we systematically searched and summarized the evidence on the immune response and reinfection rate following SARS‐CoV‐2 infection. We also retrieved studies on SARS‐CoV and MERS‐CoV to assess the long‐term duration of antibody responses. A protocol based on Cochrane rapid review methodology was adhered to and databases were searched from 1/1/2000 until 26/5/2020. Of 4744 citations retrieved, 102 studies met our inclusion criteria. Seventy‐four studies were retrieved on SARS‐CoV‐2. While the rate and timing of IgM and IgG seroconversion were inconsistent across studies, most seroconverted for IgG within 2 weeks and 100% (N = 62) within 4 weeks. IgG was still detected at the end of follow‐up (49‐65 days) in all patients (N = 24). Neutralizing antibodies were detected in 92%‐100% of patients (up to 53 days). It is not clear if reinfection with SARS‐CoV‐2 is possible, with studies more suggestive of intermittent detection of residual RNA. Twenty‐five studies were retrieved on SARS‐CoV. In general, SARS‐CoV‐specific IgG was maintained for 1‐2 years post‐infection and declined thereafter, although one study detected IgG up to 12 years post‐infection. Neutralizing antibodies were detected up to 17 years in another study. Three studies on MERS‐CoV reported that IgG may be detected up to 2 years. In conclusion, limited early data suggest that most patients seroconvert for SARS‐CoV‐2‐specific IgG within 2 weeks. While the long‐term duration of antibody responses is unknown, evidence from SARS‐CoV studies suggest SARS‐CoV‐specific IgG is sustained for 1‐2 years and declines thereafter.

The collection of nasopharyngeal swabs to test for the presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an invasive technique with implications for patients and clinicians. Alternative clinical specimens from the upper respiratory tract may offer benefits in terms of collection, comfort and infection risk. The objective of this review was to synthesise the evidence for detection of SARS-CoV-2 ribonucleic acid (RNA) using reverse transcription polymerase chain reaction (RT-PCR) tested saliva or nasal specimens compared with RT-PCR tested nasopharyngeal specimens. Searches were conducted in PubMed, Embase, Europe PMC and NHS evidence from December 2019 to 20 July 2020. Eighteen studies were identified; 12 for saliva, four for nasal and two included both specimen types. For saliva-based studies, the proportion of saliva samples testing positive relative to all positive samples in each study ranged from 82.9% to 100%; detection in nasopharyngeal specimens ranged from 76.7% to 100%; positive agreement between specimens for overall detection ranged from 65.4% to 100%.For nasal-based studies, the proportion of nasal swabs testing positive relative to all positive samples in each study ranged from 81.9% to 100%; detection in nasopharyngeal specimens ranged from 70% to 100%; positive agreement between specimens for overall detection ranged from 62.3% to 100%. The results indicate an inconsistency in the detection of SARS-CoV-2 RNA in the specimen types included, often with neither the index nor the reference of interest detecting all known cases. Depending on the test environment, these clinical specimens may offer a viable alternative to standard. However, at present the evidence is limited, of variable quality, and relatively inconsistent.

The most effective means of preventing seasonal influenza is through vaccination. In this systematic review, we investigated the efficacy, effectiveness and safety of MF59® adjuvanted trivalent and quadrivalent influenza vaccines to prevent laboratory‐confirmed influenza. A systematic literature search was conducted in electronic databases and grey literature sources up to 7 February 2020. Randomised controlled trials and non‐randomised studies of interventions (NRSIs) were eligible for inclusion. The search returned 28,846 records, of which 48 studies on MF59® adjuvanted vaccines met our inclusion criteria. No efficacy trials were identified. In terms of vaccine effectiveness (VE), MF59® adjuvanted trivalent influenza vaccines were effective in preventing laboratory‐confirmed influenza in older adults (aged ≥65 years) compared with no vaccination (VE = 45%, 95% confidence interval (CI) 23%–61%, 5 NRSIs across 3 influenza seasons). By subtype, significant effect was found for influenza A(H1N1) (VE = 61%, 95% CI 44%–73%) and B (VE = 29%, 95% CI 5%–46%), but not for A(H3N2). In terms of relative VE, there was no significant difference comparing MF59® adjuvanted trivalent vaccines with either non‐adjuvanted trivalent or quadrivalent vaccines. Compared with traditional trivalent influenza vaccines, MF59® adjuvanted trivalent influenza vaccines were associated with a greater number of local adverse events (RR = 1.90, 95% CI 1.50–2.39) and systemic reactions (RR = 1.18, 95% CI 1.02–1.38). In conclusion, MF59® adjuvanted trivalent influenza vaccines were found to be more effective than ‘no vaccination’. Based on limited data, there was no significant difference comparing the effectiveness of MF59® adjuvanted vaccines with their non‐adjuvanted counterparts.

Real-time PCR was employed to detect a region of the Mycoplasma genitalium mg219 gene, a gene of unknown function, in clinical samples. Amplification of DNA and signal production from 15 other species of human mycoplasmas and 14 other bacteria and viruses did not occur. Using a panel of 208 genital and rectal samples, the sensitivity when compared to the modified mgpa gene (encoding the major surface protein MgPa) real-time PCR assay was found to be 100 % and the specificity of the assay 99.5 % with a positive predictive value of 80 % and a negative predictive value of 100 %. The mg219 gene was found to be in all strains of M. genitalium and was highly conserved. M. genitalium was detected in 3.9 % (11/280, 95 % CI 2.1-6.9) of all male specimens, in 7.7 % (10/130, 95 % CI 4.1-13.7) of patients with non-gonococcal urethritis (NGU) and in 0.7 % (1/150, 95 % CI ,0.01-4.1) of patients without urethritis. The presence of M. genitalium was significantly associated with NGU (P ¡0.01; 95 % Cl 0.88-0.98) and nonchlamydial-non-gonococcal urethritis (P50.0005; 95 % Cl 0.84-0.97). INTRODUCTIONMycoplasma genitalium is a sexually transmitted bacterium that is primarily found in the human urogenital tract. It has also been detected in respiratory (Baseman et al., 1988), rectal (Taylor-Robinson et al., 2003) and synovial (Tully et al., 1995) specimens. Serological detection of M. genitalium is problematic due to cross-reactions with Mycoplasma pneumoniae antibodies (Clausen et al., 2001;Lind et al., 1984). Isolation via cell culture is slow and laborious and real-time PCR is currently used in the diagnosis of infected patients (Jensen, 2006). Originally isolated from men with urethritis (Tully et al., 1981), M. genitalium has been convincingly linked to non-gonococcal urethritis (NGU) and nonchlamydial-non-gonococcal urethritis (NCNGU) (Jensen, 2006). However, the full extent of M. genitalium infection, epidemiology, and role in cervicitis, pelvic inflammatory disease, infertility and other infections requires investigation (Jensen, 2006). M. genitalium is sexually transmitted and a high prevalence has been found (58 %) in individuals with infected sexual partners (Keane et al., 2000). Sequence-based typing has identified identical isolate sequence types from sexual partners, cementing evidence for sexual transmission (Hjorth et al., 2006;Ma et al., 2008).Several real-time PCR assays have been described for the molecular detection of M. genitalium, including those targeting mgpa, the 16S rRNA gene and p115 (for review see Jensen, 2006). The mgpa gene real-time assay has been shown to be of increased sensitivity to the 16S rRNA method (Edberg et al., 2008). We sought to identify a new method for confirmation of PCR results with equal sensitivity to that of the mgpa gene assay. The mg219 gene assay was developed and used to detect the presence of M. genitalium in parallel with the mgpa gene real-time PCR assay in 280 male genitourinary medicine clinic attendees and 23 female partners as part of a case-control doubleblinded study ...