The Treatment Action Campaign (TAC), South Africa's – and probably the world's – most prominent AIDS activist movement, emerged in the context of state-supported AIDS denialism and government resistance to evidence-based responses such as antiretroviral treatment. TAC's forceful campaigns against denialism and in favour of the provision of antiretroviral drugs are widely lauded and even credited with the dramatic policy turnaround in South Africa. This study draws on extensive interviews with TAC leaders and members to provide a detailed historical narrative of the emergence and impact of TAC, while employing a range of theoretical approaches to help explain its influence. It describes how TAC's founders drew on their experiences and networks from the anti-apartheid struggle to build the movement and construct new local and international support networks in order to gain influence. It concludes that TAC succeeded in leveraging ‘networks of influence’ (which also included scientists, bureaucrats and politicians) to contribute to the formation of a moral consensus on treatment access and the construction of an inclusive coalition that pursued policy change.

BACKGROUND: In 1998 we estimated that 34/million infectious window period donations were entering the blood supply at the South African National Blood Service. Selective use of donations based on donor race‐ethnicity reduced this risk to 26/million donations but was deemed unethical. Consequently, in 2005 South African National Blood Service eliminated race‐ethnicity–based collection policies and implemented individual‐donation nucleic acid testing (ID‐NAT). We describe the change in donor base demographics, human immunodeficiency virus (HIV) detection rates, and transfusion‐transmissible HIV risk.STUDY DESIGN AND METHODS: In ten years 7.7 million donations were tested for anti‐HIV and HIV RNA. Number of donations, HIV prevalence, ID‐NAT yield rate, serology yield rate and residual transfusion‐transmissible HIV risk were analyzed by donor type, race‐ethnicity, age, and sex. Multiple regression analysis was performed to investigate the determinants of HIV‐positive and nucleic acid testing yield donations.RESULTS: The combined strategy of increasing donations from black donors and implementing ID‐NAT increased the proportion of donations from black donors from 6% in 2005 to 30% in 2015 (p < 0.00001), and reduced the transfusion‐transmissible risk from 24 to 13 per million transfusions. ID‐NAT interdicted 481 (1:16,100) seronegative window period donations, while one transfusion‐transmissible case (0.13 per million) was documented. Race‐ethnicity and donor type were highly significant predictors of HIV positivity, with adjusted odds ratio for first‐time donors of 12.5 (95% confidence interval, 11.9‐13.1) and for black race‐ethnicity of 31.1 (95% confidence interval, 28.9‐33.4). The proportion of serology yields among HIV‐infected donors increased from 0.27% to 2.4%.CONCLUSION: ID‐NAT enabled the South African National Blood Service to increase the number of donations from black donors fivefold while enhancing the safety of the blood supply.

Dengue virus (DENV) infections elicit antibody responses to the non-structural protein 1 (NS1) that are associated with protection against disease. However, the antibody isotypes and subclasses involved, and their kinetics have not been extensively studied. We characterized the antibody responses to DENV NS1 by enzyme-linked immunosorbent assay (ELISA) in a longitudinal cohort of 266 confirmed dengue cases in Recife, Northeast Brazil. Samples were collected during the febrile phase and up to over 3 years after onset of symptoms. The antibodies investigated [IgA, IgM, total IgG (all subclasses measured together) and each subclass (IgG2, IgG3 and IgG4) measured separately] had distinct kinetic profiles following primary or secondary DENV infections. Of interest, most of these antibodies were consistently detected greater than 6 months after onset of symptoms, except for IgG3. Anti-dengue NS1-specific IgG was consistently detected from the acute phase to beyond 3 years after symptom onset. In contrast, anti-dengue NS1-specific IgG3 was detected within the first week, peaked at week 2-3, and disappeared within 4-6 months after onset of symptoms. The mean duration of the IgG3 positive signal was 149 days (ranging from 126 to 172 days). In conclusion, anti-dengue NS1-specific IgG and IgG3 are potential biomarkers of long-term and recent (less than 6 months) DENV infections, respectively.

Background: Antibody response duration following severe acute respiratory syndrome coronavirus 2 infection tends to be variable and depends on severity of disease and method of detection.Study design and methods: COVID‐19 convalescent plasma from 18 donors was collected longitudinally for a maximum of 63–129 days following resolution of symptoms. All the samples were initially screened by the Ortho total Ig test to confirm positivity and subsequently tested with seven additional direct sandwich or indirect binding assays (Ortho, Roche, Abbott, Broad Institute) directed against a variety of antigen targets (S1, receptor binding domain, and nucleocapsid [NC]), along with two neutralization assays (Broad Institute live virus PRNT and Vitalant Research Institute [VRI] Pseudovirus reporter viral particle neutralization [RVPN]).Results: The direct detection assays (Ortho total Ig total and Roche total Ig) showed increasing levels of antibodies over the time period, in contrast to the indirect IgG assays that showed a decline. Neutralization assays also demonstrated declining responses; the VRI RVPN pseudovirus had a greater rate of decline than the Broad PRNT live virus assay.Discussion: These data show that in addition to variable individual responses and associations with disease severity, the detection assay chosen contributes to the heterogeneous results in antibody stability over time. Depending on the scope of the research, one assay may be preferable over another. For serosurveillance studies, direct, double Ag‐sandwich assays appear to be the best choice due to their stability; in particular, algorithms that include both S1‐ and NC‐based assays can help reduce the rate of false‐positivity and discriminate between natural infection and vaccine‐derived seroreactivity.

Background: HIV assays designed to detect recent infection, also known as “recency assays,” are often used to estimate HIV incidence in a specific country, region, or subpopulation, alone or as part of recent infection testing algorithms (RITAs). Recently, many countries and organizations have become interested in using recency assays within case surveillance systems and routine HIV testing services to measure other indicators beyond incidence, generally referred to as “non-incidence surveillance use cases.” Objective: This review aims to identify published evidence that can be used to validate methodological approaches to recency-based incidence estimation and non-incidence use cases. The evidence identified through this review will be used in the forthcoming technical guidance by the World Health Organization (WHO) and United Nations Programme on HIV/AIDS (UNAIDS) on the use of HIV recency assays for identification of epidemic trends, whether for HIV incidence estimation or non-incidence indicators of recency. Methods: To identify the best methodological and field implementation practices for the use of recency assays to estimate HIV incidence and trends in recent infections for specific populations or geographic areas, we conducted a systematic review of the literature to (1) understand the use of recency testing for surveillance in programmatic and laboratory settings, (2) review methodologies for implementing recency testing for both incidence estimation and non-incidence use cases, and (3) assess the field performance characteristics of commercially available recency assays. Results: Among the 167 documents included in the final review, 91 (54.5%) focused on assay or algorithm performance or methodological descriptions, with high-quality evidence of accurate age- and sex-disaggregated HIV incidence estimation at national or regional levels in general population settings, but not at finer geographic levels for prevention prioritization. The remaining 76 (45.5%) described the field use of incidence assays including field-derived incidence (n=45), non-incidence (n=25), and both incidence and non-incidence use cases (n=6). The field use of incidence assays included integrating RITAs into routine surveillance and assisting with molecular genetic analyses, but evidence was generally weaker or only reported on what was done, without validation data or findings related to effectiveness of using non-incidence indicators calculated through the use of recency assays as a proxy for HIV incidence. Conclusions: HIV recency assays have been widely validated for estimating HIV incidence in age- and sex-specific populations at national and subnational regional levels; however, there is a lack of evidence validating the accuracy and effectiveness of using recency assays to identify epidemic trends in non-incidence surveillance use cases. More research is needed to validate the use of recency assays within HIV testing services, to ensure findings can be accurately interpreted to guide prioritization of public health programming.