The Second Round of a Population-Based Seroprevalence Study of Anti-SARS-CoV-2 Antibodies and COVID-19 Vaccination Assessment in the Republika Srpska, Bosnia and Herzegovina.

Introduction: The aim of the study was to assess the seroprevalence of SARS-CoV-2 in the Republika Srpska, Bosnia and Herzegovina, after five waves of COVID-19 and 1 year after introduction of vaccination to better understand the true extent of the COVID-19 pandemic in the population of the Republika Srpska and role of vaccination in achieving herd immunity.

Methods: The population-based study was conducted from December 2021 to February 2022 in a group of 4463 individuals in the Republika Srpska. Total anti-SARS-CoV-2 antibodies were determined in serum specimens using the Wantai total antibody ELISA assay.

Assessing whether providing regular, free HIV self-testing kits reduces the time to HIV diagnosis: an internet-based, randomised controlled trial in men who have sex with men.

Background: The risk of onwards HIV transmission is strongly influenced by the interval between HIV infection and its diagnosis. The SELPHI trial examined whether this interval could be reduced by offering free HIV self-testing kits to men-who-have-sex with-men (MSM).

Setting: Internet-based RCT of MSM aged ≥16 years, resident in England/Wales, recruited via sexual and social networking sites.

Case-only analysis of routine surveillance data: detection of increased vaccine breakthrough infections with SARS-CoV-2 variants in Europe.

With the ongoing emergence of SARS-CoV-2 variants, there is a need for standard approaches to characterize the risk of vaccine breakthrough. We aimed to estimate the association between variant and vaccination status in case-only surveillance data. Included cases were symptomatic adult laboratory-confirmed COVID-19 cases, with onset between January 2021 and April 2022, reported by five European countries (Estonia, Ireland, Luxembourg, Poland, and Slovakia) to The European Surveillance System.

Possible scenarios for the spread of mpox outside the endemic focus in Africa.

The recent expansion of mpox in Africa is characterized by a dramatic increase in zoonotic transmission (clade Ia) and the emergence of a new clade Ib that is transmitted from human to human by close contact. Clade Ia does not pose a threat in areas without zoonotic reservoirs. But clade Ib may spread widely, as did clade IIb which has spread globally since 2022 among men who have sex with men.

COVID-19 vaccine effectiveness against SARS-CoV-2-confirmed hospitalisation in the eastern part of the WHO European Region (2022-2023): a test-negative case-control study from the EuroSAVE network.

Background: Understanding COVID-19 vaccine effectiveness (VE) in preventing severe disease is critical to inform vaccine policy. We used the test-negative design to estimate VE against SARS-CoV-2-confirmed hospitalisation in adults ≥18 years in the eastern WHO European Region.

Methods: We included patients hospitalised for severe acute respiratory infection (SARI) at sentinel surveillance sites in Albania, Georgia, Kyrgyzstan, North Macedonia, Serbia, and in Kosovo.