Objective To conduct a systematic review and meta-analysis of randomised controlled trials (RCTs) of the effectiveness and safety of oral pre-exposure prophylaxis (PrEP) to prevent HIV. Methods Databases (PubMed, Embase and the Cochrane Register of Controlled Trials) were searched up to 5 July 2020. Search terms for ‘HIV’ were combined with terms for ‘PrEP’ or ‘tenofovir/emtricitabine’. RCTs were included that compared oral tenofovir-containing PrEP to placebo, no treatment or alternative medication/dosing schedule. The primary outcome was the rate ratio (RR) of HIV infection using a modified intention-to-treat analysis. Secondary outcomes included safety, adherence and risk compensation. All analyses were stratified a priori by population: men who have sex with men (MSM), serodiscordant couples, heterosexuals and people who inject drugs (PWIDs). The quality of individual studies was assessed using the Cochrane risk-of-bias tool, and the certainty of evidence was assessed using GRADE. Results Of 2803 unique records, 15 RCTs met our inclusion criteria. Over 25 000 participants were included, encompassing 38 289 person-years of follow-up data. PrEP was found to be effective in MSM (RR 0.25, 95% CI 0.1 to 0.61; absolute rate difference (RD) −0.03, 95% CI −0.01 to −0.05), serodiscordant couples (RR 0.25, 95% CI 0.14 to 0.46; RD −0.01, 95% CI −0.01 to −0.02) and PWID (RR 0.51, 95% CI 0.29 to 0.92; RD −0.00, 95% CI −0.00 to −0.01), but not in heterosexuals (RR 0.77, 95% CI 0.46 to 1.29). Efficacy was strongly associated with adherence (p<0.01). PrEP was found to be safe, but unrecognised HIV at enrolment increased the risk of viral drug resistance mutations. Evidence for behaviour change or an increase in sexually transmitted infections was not found. Conclusions PrEP is safe and effective in MSM, serodiscordant couples and PWIDs. Additional research is needed prior to recommending PrEP in heterosexuals. No RCTs reported effectiveness or safety data for other high-risk groups, such as transgender women and sex workers. PROSPERO registration number CRD42017065937.

Summary: A key consideration in the Covid‐19 pandemic is the dominant modes of transmission of the severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) virus. The objective of this review was to synthesise the evidence for the potential airborne transmission of SARS‐CoV‐2 via aerosols. Systematic literature searches were conducted in PubMed, Embase, Europe PMC and National Health Service UK evidence up to 27 July 2020. A protocol was published and Cochrane guidance for rapid review methodology was adhered to throughout. Twenty‐eight studies were identified. Seven out of eight epidemiological studies suggest aerosol transmission may occur, with enclosed environments and poor ventilation noted as possible contextual factors. Ten of the 16 air sampling studies detected SARS‐CoV‐2 ribonucleic acid; however, only three of these studies attempted to culture the virus with one being successful in a limited number of samples. Two of four virological studies using artificially generated aerosols indicated that SARS‐CoV‐2 is viable in aerosols. The results of this review indicate there is inconclusive evidence regarding the viability and infectivity of SARS‐CoV‐2 in aerosols. Epidemiological studies suggest possible transmission, with contextual factors noted. Viral particles have been detected in air sampling studies with some evidence of clinical infectivity, and virological studies indicate these particles may represent live virus, adding further plausibility. However, there is uncertainty as to the nature and impact of aerosol transmission of SARS‐CoV‐2, and its relative contribution to the Covid‐19 pandemic compared with other modes of transmission.

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.

Human papillomavirus (HPV) infection has been identified as a significant etiological agent in the development of head and neck squamous cell carcinoma (HNSCC). HPV’s involvement has alluded to better survival and prognosis in patients and suggests that different treatment strategies may be appropriate for them. Only some data on the epidemiology of HPV infection in the oropharyngeal, oral cavity, and laryngeal SCC exists in Europe. Thus, this study was carried out to investigate HPV’s impact on HNSCC patient outcomes in the Irish population, one of the largest studies of its kind using consistent HPV testing techniques. A total of 861 primary oropharyngeal, oral cavity, and laryngeal SCC (OPSCC, OSCC, LSCC) cases diagnosed between 1994 and 2013, identified through the National Cancer Registry of Ireland (NCRI), were obtained from hospitals across Ireland and tested for HPV DNA using Multiplex PCR Luminex technology based in and sanctioned by the International Agency for Research on Cancer (IARC). Both overall and cancer-specific survival were significantly improved amongst all HPV-positive patients together, though HPV status was only a significant predictor of survival in the oropharynx. Amongst HPV-positive patients in the oropharynx, surgery alone was associated with prolonged survival, alluding to the potential for de-escalation of treatment in HPV-related OPSCC in particular. Cumulatively, these findings highlight the need for continued investigation into treatment pathways for HPV-related OPSCC, the relevance of introducing boys into national HPV vaccination programs, and the relevance of the nona-valent Gardasil-9 vaccine to HNSCC prevention.