Safety and immunogenicity of booster vaccination and fractional dosing with Ad26.COV2.S or BNT162b2 in Ad26.COV2.S-vaccinated participants

We report the safety and immunogenicity of fractional and full dose Ad26.COV2.S and BNT162b2 in an open label phase 2 trial of participants previously vaccinated with a single dose of Ad26.COV2.S, with 91.4% showing evidence of previous SARS-CoV-2 infection. A total of 286 adults (with or without HIV) were enrolled >4 months after an Ad26.COV2.S prime and randomized 1:1:1:1 to receive either a full or half-dose booster of Ad26.COV2.S or BNT162b2 vaccine. B cell responses (binding, neutralization and antibody dependent cellular cytotoxicity-ADCC), and spike-specific T-cell responses were evaluated at baseline, 2, 12 and 24 weeks post-boost. Antibody and T-cell immunity targeting the Ad26 vector was also evaluated. No vaccine-associated serious adverse events were recorded. The full- and half-dose BNT162b2 boosted anti-SARS-CoV-2 binding antibody levels (3.9- and 4.5-fold, respectively) and neutralizing antibody levels (4.4- and 10-fold). Binding and neutralizing antibodies following half-dose Ad26.COV2.S were not significantly boosted. Full-dose Ad26.COV2.S did not boost binding antibodies but slightly enhanced neutralizing antibodies (2.1-fold). ADCC was marginally increased only after a full-dose BNT162b2. T-cell responses followed a similar pattern to neutralizing antibodies. Six months post-boost, antibody and T-cell responses had waned to baseline levels. While we detected strong anti-vector immunity, there was no correlation between anti-vector immunity in Ad26.COV2.S recipients and spike-specific neutralizing antibody or T-cell responses post-Ad26.COV2.S boosting. Overall, in the context of hybrid immunity, boosting with heterologous full- or half-dose BNT162b2 mRNA vaccine demonstrated superior immunogenicity 2 weeks post-vaccination compared to homologous Ad26.COV2.S, though rapid waning occurred by 12 weeks post-boost. Trial Registration: The study has been registered to the South African National Clinical Trial Registry (SANCTR): DOH-27-012022-7841. The approval letter from SANCTR has been provided in the up-loaded documents.

COVID-19 vaccine efficacy in participants with weakened immune systems from four randomized-controlled trials

BACKGROUND

Although the SARS-CoV-2 vaccines are highly efficacious at preventing severe disease in the general population, current data are lacking regarding vaccine efficacy (VE) for individuals with mild immunocompromising conditions.

METHODS

A post-hoc, cross-protocol analysis of participant-level data from the blinded phase of four randomized, placebo-controlled, COVID-19 vaccine phase 3 trials (Moderna, AstraZeneca, Janssen, and Novavax) was performed. We defined a "tempered immune system" (TIS) variable via a consensus panel based on medical history and medications to determine VE against symptomatic and severe COVID-19 cases in TIS participants versus non-TIS (NTIS) individuals starting at 14 days after completion of the primary series through the blinded phase for each of the four trials. An analysis of participants living with well-controlled HIV was conducted using the same methods.

RESULTS

3,852/30,351 (12.7%) Moderna participants, 3,088/29,868 (10.3%) Novavax participants, 3,549/32,380 (11.0%) AstraZeneca participants, and 5,047/43,788 (11.5%) Janssen participants were identified as having a TIS. Most TIS conditions (73.9%) were due to metabolism and nutritional disorders. Vaccination (versus placebo) significantly reduced the likelihood of symptomatic and severe COVID-19 for all participants for each trial. VE was not significantly different for TIS participants vs NTIS for either symptomatic or severe COVID-19 for each trial, nor was VE significantly different in the symptomatic endpoint for participants with HIV.

CONCLUSIONS

For individuals with mildly immunocompromising conditions, there is no evidence of differences in VE against symptomatic or severe COVID-19 compared to those with non-tempered immune systems in the four COVID-19 vaccine randomized controlled efficacy trials.

Classification of early tuberculosis states to guide research for improved care and prevention: an international Delphi consensus exercise

The current active-latent paradigm of tuberculosis largely neglects the documented spectrum of disease. Inconsistency with regard to definitions, terminology, and diagnostic criteria for different tuberculosis states has limited the progress in research and product development that are needed to achieve tuberculosis elimination. We aimed to develop a new framework of classification for tuberculosis that accommodates key disease states but is sufficiently simple to support pragmatic research and implementation. Through an international Delphi exercise that involved 71 participants representing a wide range of disciplines, sectors, income settings, and geographies, consensus was reached on a set of conceptual states, related terminology, and research gaps. The International Consensus for Early TB (ICE-TB) framework distinguishes disease from infection by the presence of macroscopic pathology and defines two subclinical and two clinical tuberculosis states on the basis of reported symptoms or signs of tuberculosis, further differentiated by likely infectiousness. The presence of viable Mycobacterium tuberculosis and an associated host response are prerequisites for all states of infection and disease. Our framework provides a clear direction for tuberculosis research, which will, in time, improve tuberculosis clinical care and elimination policies.

Frequency, kinetics and determinants of viable SARS-CoV-2 in bioaerosols from ambulatory COVID-19 patients infected with the Beta, Delta or Omicron variants

Airborne transmission of SARS-CoV-2 aerosol remains contentious. Importantly, whether cough or breath-generated bioaerosols can harbor viable and replicating virus remains largely unclarified. We performed size-fractionated aerosol sampling (Andersen cascade impactor) and evaluated viral culturability in human cell lines (infectiousness), viral genetics, and host immunity in ambulatory participants with COVID-19. Sixty-one percent (27/44) and 50% (22/44) of participants emitted variant-specific culture-positive aerosols <10μm and <5μm, respectively, for up to 9 days after symptom onset. Aerosol culturability is significantly associated with lower neutralizing antibody titers, and suppression of transcriptomic pathways related to innate immunity and the humoral response. A nasopharyngeal Ct <17 rules-in ~40% of aerosol culture-positives and identifies those who are probably highly infectious. A parsimonious three transcript blood-based biosignature is highly predictive of infectious aerosol generation (PPV > 95%). There is considerable heterogeneity in potential infectiousness i.e., only 29% of participants were probably highly infectious (produced culture-positive aerosols <5μm at ~6 days after symptom onset). These data, which comprehensively confirm variant-specific culturable SARS-CoV-2 in aerosol, inform the targeting of transmission-related interventions and public health containment strategies emphasizing improved ventilation.

Safety of a second homologous Ad26.COV2.S vaccine among healthcare workers in the phase 3b implementation Sisonke study in South Africa

The Sisonke 2 study provided a homologous boost at least 6 months after administration of the priming dose of Ad26.COV2.S for healthcare workers enrolled on the Sisonke phase 3b implementation study. Safety monitoring was via five reporting sources: (i.) self-report through a web-link; (ii.) paper-based case report forms; (iii.) a toll-free telephonic reporting line; (iv.) healthcare professionals-initiated reports; and (v.) active linkage with National Disease Databases. A total of 2350 adverse events were reported by 2117 of the 240 888 (0.88%) participants enrolled; 1625 of the 2350 reported events are reactogenicity events and 28 adverse events met seriousness criteria. No cases of thrombosis with thrombocytopaenia syndrome were reported; all adverse events including thromboembolic disorders occurred at a rate below the expected population rates apart from one case of Guillain Barre Syndrome and one case of portal vein thrombosis. The Sisonke 2 study demonstrates that two doses of Ad26.COV2.S is safe and well tolerated; and provides a feasible model for national pharmacovigilance strategies for low- and middle-income settings.

The Functional Assessment of Cancer Therapy Scale: Development and Validation of the General Measure

PURPOSE

We developed and validated a brief, yet sensitive, 33-item general cancer quality-of-life (QL) measure for evaluating patients receiving cancer treatment, called the Functional Assessment of Cancer Therapy (FACT) scale.

METHODS AND RESULTS

The five-phase validation process involved 854 patients with cancer and 15 oncology specialists. The initial pool of 370 overlapping items for breast, lung, and colorectal cancer was generated by open-ended interview with patients experienced with the symptoms of cancer and oncology professionals. Using preselected criteria, items were reduced to a 38-item general version. Factor and scaling analyses of these 38 items on 545 patients with mixed cancer diagnoses resulted in the 28-item FACT-general (FACT-G, version 2). In addition to a total score, this version produces subscale scores for physical, functional, social, and emotional well-being, as well as satisfaction with the treatment relationship. Coefficients of reliability and validity were uniformly high. The scale's ability to discriminate patients on the basis of stage of disease, performance status rating (PSR), and hospitalization status supports its sensitivity. It has also demonstrated sensitivity to change over time. Finally, the validity of measuring separate areas, or dimensions, of QL was supported by the differential responsiveness of subscales when applied to groups known to differ along the dimensions of physical, functional, social, and emotional well-being.

CONCLUSION

The FACT-G meets or exceeds all requirements for use in oncology clinical trials, including ease of administration, brevity, reliability, validity, and responsiveness to clinical change. Selecting it for a clinical trial adds the capability to assess the relative weight of various aspects of QL from the patient's perspective.

Safety and immunogenicity of booster vaccination and fractional dosing with Ad26.COV2.S or BNT162b2 in Ad26.COV2.S-vaccinated participants

Background

We report the safety and immunogenicity of fractional and full dose Ad26.COV2.S and BNT162b2 in an open label phase 2 trial of participants previously vaccinated with a single dose of Ad26.COV2.S, with 91.4% showing evidence of previous SARS-CoV-2 infection.

Methods

A total of 286 adults (with or without HIV) were enrolled >4 months after an Ad26.COV2.S prime and randomized 1:1:1:1 to receive either a full or half-dose booster of Ad26.COV2.S or BNT162b2 vaccine. B cell responses (binding, neutralization and antibody dependent cellular cytotoxicity-ADCC), and spike-specific T-cell responses were evaluated at baseline, 2, 12 and 24 weeks post-boost. Antibody and T-cell immunity targeting the Ad26 vector was also evaluated.

Results

No vaccine-associated serious adverse events were recorded. The full- and half-dose BNT162b2 boosted anti-SARS-CoV-2 binding antibody levels (3.9- and 4.5-fold, respectively) and neutralizing antibody levels (4.4- and 10-fold). Binding and neutralizing antibodies following half-dose Ad26.COV2.S were not significantly boosted. Full-dose Ad26.COV2.S did not boost binding antibodies but slightly enhanced neutralizing antibodies (2.1-fold). ADCC was marginally increased only after a full-dose BNT162b2. T-cell responses followed a similar pattern to neutralizing antibodies. Six months post-boost, antibody and T-cell responses had waned to baseline levels. While we detected strong anti-vector immunity, there was no correlation between anti-vector immunity in Ad26.COV2.S recipients and spike-specific neutralizing antibody or T-cell responses post-Ad26.COV2.S boosting.

Conclusion

In the context of hybrid immunity, boosting with heterologous full- or half-dose BNT162b2 mRNA vaccine demonstrated superior immunogenicity 2 weeks post-vaccination compared to homologous Ad26.COV2.S, though rapid waning occurred by 12 weeks post-boost.

Trial Registration

South African National Clinical Trial Registry (SANCR): DOH-27-012022-7841.

Funding

South African Medical Research Council (SAMRC) and South African Department of Health (SA DoH).

Homologous Ad26.COV2.S vaccination results in reduced boosting of humoral responses in hybrid immunity, but elicits antibodies of similar magnitude regardless of prior infection

The impact of previous SARS-CoV-2 infection on the durability of Ad26.COV2.S vaccine-elicited responses, and the effect of homologous boosting has not been well explored. We followed a cohort of healthcare workers for 6 months after receiving the Ad26.COV2.S vaccine and a further one month after they received an Ad26.COV2.S booster dose. We assessed longitudinal spike-specific antibody and T cell responses in individuals who had never had SARS-CoV-2 infection, compared to those who were infected with either the D614G or Beta variants prior to vaccination. Antibody and T cell responses elicited by the primary dose were durable against several variants of concern over the 6 month follow-up period, regardless of infection history. However, at 6 months after first vaccination, antibody binding, neutralization and ADCC were as much as 59-fold higher in individuals with hybrid immunity compared to those with no prior infection. Antibody cross-reactivity profiles of the previously infected groups were similar at 6 months, unlike at earlier time points, suggesting that the effect of immune imprinting diminishes by 6 months. Importantly, an Ad26.COV2.S booster dose increased the magnitude of the antibody response in individuals with no prior infection to similar levels as those with previous infection. The magnitude of spike T cell responses and proportion of T cell responders remained stable after homologous boosting, concomitant with a significant increase in long-lived early differentiated CD4 memory T cells. Thus, these data highlight that multiple antigen exposures, whether through infection and vaccination or vaccination alone, result in similar boosts after Ad26.COV2.S vaccination.

Understanding drivers of female sex workers' experiences of external/enacted and internalised stigma: findings from a cross-sectional community-centric national study in South Africa

To deepen our understanding of sex work stigma, and to its drivers and their interrelation, we conducted an analysis using structural equation modelling of the South African National Sex Worker Survey. We enrolled 3005 women in sex work using multi-stage sampling across all South Africa's provinces. Experience of external/enacted and internalised stigma was widespread. Non-partner rape, intimate partner violence and partner controlling behaviour (often expressions of external/enacted stigma) compounded internalised stigma. These experiences of violence, other manifestations of external/enacted stigma and food insecurity, were key drivers of internalised stigma, and often had an impact on mental health. We found that considerable protection against stigma emanated from viewing sex work positively. This resistance to stigma provided opportunities to shift the narrative. Reducing sex workers' exposure to external/enacted stigmatising behaviour, including by enabling more to work indoors, and providing greater protection from partner violence and rape, are critical for better health and well-being. Ending the criminalisation of sex work is foundational for safer working conditions and better health outcomes for sex workers, similarly providing adequately funded mental and physical health and social care through sex work specific programmes.

Infection pre-Ad26.COV2.S-vaccination primes greater class switching and reduced CXCR5 expression by SARS-CoV-2-specific memory B cells

Neutralizing antibodies strongly correlate with protection for COVID-19 vaccines, but the corresponding memory B cells that form to protect against future infection are relatively understudied. Here we examine the effect of prior SARS-CoV-2 infection on the magnitude and phenotype of the memory B cell response to single dose Johnson and Johnson (Ad26.COV2.S) vaccination in South African health care workers. Participants were either naïve to SARS-CoV-2 or had been infected before vaccination. SARS-CoV-2-specific memory B-cells expand in response to Ad26.COV2.S and are maintained for the study duration (84 days) in all individuals. However, prior infection is associated with a greater frequency of these cells, a significant reduction in expression of the germinal center chemokine receptor CXCR5, and increased class switching. These B cell features correlated with neutralization and antibody-dependent cytotoxicity (ADCC) activity, and with the frequency of SARS-CoV-2 specific circulating T follicular helper cells (cTfh). Vaccination-induced effective neutralization of the D614G variant in both infected and naïve participants but boosted neutralizing antibodies against the Beta and Omicron variants only in participants with prior infection. In addition, the SARS-CoV-2 specific CD8+ T cell response correlated with increased memory B cell expression of the lung-homing receptor CXCR3, which was sustained in the previously infected group. Finally, although vaccination achieved equivalent B cell activation regardless of infection history, it was negatively impacted by age. These data show that phenotyping the response to vaccination can provide insight into the impact of prior infection on memory B cell homing, CSM, cTfh, and neutralization activity. These data can provide early signals to inform studies of vaccine boosting, durability, and co-morbidities.

Cholera vaccine clinical trials: A cross-sectional analysis of clinical trials registries

Cholera has been one of the world's biggest public health challenges for centuries. The presence of this disease brings into focus the social determinants of health in different parts of the world. Research and development efforts to find safe and effective Cholera vaccines are critical to decreasing the disease burden from Vibrio cholerae. We searched the International Clinical Trials Registry Platform (ICTRP) and Cochrane Central Register of Controlled Trials (CENTRAL) on 5 March 2023. We included all registered randomized trials studying Cholera vaccines. We used Microsoft Excel to perform a descriptive analysis of the source registry, geographic distribution, recruitment status, phase of trials, and type of trial sponsor and presented the findings using tables and graphs. The search of ICTRP yielded 84 trials, and 315 trials were identified from CENTRAL. Seventy-four trials were included in the analysis. Most of the trials (66%, n = 49) were registered in ClinicalTrials.gov, followed by Clinical Trials Registry - India (9%, n = 7) and the Cuban Public Registry of Clinical Trials (8%, n = 6). The geographical distribution of the trials indicates that 48% (n = 36) of the trials were conducted in Asia, followed by 23% (n = 17) in North America, 15% (n = 11) in Africa, and 11% (n = 8) in Europe. Results further indicate that 81% (n = 60) of trials have a recruitment status "Not recruiting," followed by 12% (n = 9) with a status "recruiting." With the recent surge in Cholera cases and the limited supply of Cholera vaccines, research indicates the need for Cholera vaccine trials to ensure the availability of vaccines, especially in populations affected.

Modifiers of COVID-19 vaccine efficacy: Results from four COVID-19 prevention network efficacy trials

Questions remain regarding the effect of baseline host and exposure factors on vaccine efficacy (VE) across pathogens and vaccine platforms. We report placebo-controlled data from four Phase 3 COVID-19 trials during the early period of the pandemic. This was a cross-protocol analysis of four randomized, placebo-controlled efficacy trials (Moderna/mRNA1273, AstraZeneca/AZD1222, Janssen/Ad26.COV2.S, and Novavax/NVX-CoV2373) using a harmonized design. Trials were conducted in the United States and international sites in adults ≥ 18 years of age. VE was assessed for symptomatic and severe COVID-19. We analyzed 114,480 participants from both placebo and vaccine arms, enrolled July 2020 to February 2021, with follow up through July 2021. VE against symptomatic COVID-19 showed little heterogeneity across baseline socio-demographic, clinical or exposure characteristics, in either univariate or multivariate analysis, regardless of vaccine platform. Similarly, VE against severe COVID-19 in the single trial (Janssen) with sufficient endpoints for analysis showed little evidence of heterogeneity. COVID-19 VE is not influenced by baseline host or exposure characteristics across efficacy trials of different vaccine platforms and countries when well matched to circulating virus strains. This supports use of these vaccines, regardless of platform type, as effective tools in the near term for reducing symptomatic and severe COVID-19, particularly for older individuals and those with common co-morbidities during major variant shifts. Clinical trial registration numbers: NCT04470427, NCT04516746, NCT04505722, and NCT04611802.

COVID-19 as a catalyst for vaccine manufacturing: A South African experience

COVID-19 highlighted inequitable vaccine distribution and the urgent need for vaccine manufacturing capacity on the African continent. This resulted in a burst of scientific engagement and international funding to augment capacity on the continent. However, short-term investment needs to be reinforced by a robust, strategic long-term plan to ensure sustainability.

Systematic review and meta-analysis of myocarditis and pericarditis in adolescents following COVID-19 BNT162b2 vaccination

Myocarditis and pericarditis are frequent complications of COVID-19, but have also been reported following vaccination against COVID-19 in adolescents. To build vaccine confidence and inform policy, we characterized the incidence of myocarditis/pericarditis in adolescents following BNT162b2 vaccination and explored the association with dose and sex. We searched national and international databases for studies reporting the incidence of myocarditis/pericarditis following BNT162b2 vaccination as the primary endpoint. The intra-study risk of bias was appraised, and random-effects meta-analyses were performed to estimate the pooled incidence by dose stratified by sex. The pooled incidence of myocarditis/pericarditis was 4.5 (95%CI: 3.14-6.11) per 100,000 vaccinations across all doses. Compared to dose 1, the risk was significantly higher after dose 2 (RR: 8.62, 95%CI: 5.71-13.03). However, adolescents experienced a low risk after a booster dose than after dose 2 (RR: 0.06; 95%CI: 0.04-0.09). Males were approximately seven times (RR: 6.66, 95%CI: 4.77-4.29) more likely than females to present myocarditis/pericarditis. In conclusion, we found a low frequency of myocarditis/pericarditis after BNT162b2, which occurred predominantly after the second dose in male adolescents. The prognosis appears to be favorable, with full recovery in both males and females. National programs are recommended to adopt the causality framework to reduce overreporting, which undercuts the value of the COVID-19 vaccine on adolescent life, as well as to extend the inter-dose interval policy, which has been linked to a lower frequency of myocarditis/pericarditis.

Effectiveness of COVID-19 Pfizer-BioNTech (BNT162b2) mRNA vaccination in adolescents aged 12-17 years: A systematic review and meta-analysis

The rapid emergence of COVID-19 variants of concern (VOCs) has hindered vaccine uptake. To inform policy, we investigated the effectiveness of the BNT162b2 vaccination among adolescents against symptomatic and severe COVID-19 diseases using mostly real-world data (15 studies). We searched international databases until May 2022 and used Cochrane's risk of bias tools for critical appraisal. Random effects models were used to examine overall vaccine effectiveness (VE) across studies (general inverse-variance) and the effect of circulating VOCs on VE (log relative ratio and VE). Meta-regression assessed the effect of age and time on VE (restricted-maximum likelihood). BNT162b2 VE against PCR-confirmed SARS-CoV-2 was 82.7% (95%CI: 78.37-87.31%). VE was higher for severe (88%) than non-severe (35%) outcomes and declining over time improved following booster dose in omicron era [73%(95%CI:65-81%)]. Fully vaccinated adolescents are protected from COVID-19 circulating VOCs by BNT162b2 especially for the need of critical care or life support.

Counterfactual estimation of efficacy against placebo for novel PrEP agents using external trial data: example of injectable cabotegravir and oral PrEP in women

INTRODUCTION

Multiple antiretroviral agents have demonstrated efficacy for human immunodeficiency virus (HIV) pre-exposure prophylaxis (PrEP). As a result, clinical trials of novel agents have transitioned from placebo- to active-controlled designs; however, active-controlled trials do not provide an estimate of efficacy versus no use of PrEP. Counterfactual placebo comparisons using other data sources could be employed to provide this information.

METHODS

We compared the active-controlled study (HPTN 084) of injectable cabotegravir (CAB-LA) versus daily oral emtricitabine/tenofovir disoproxil fumarate (FTC/TDF) among women from seven countries in Africa to three external, contemporaneous randomized HIV prevention trials from which we constructed counterfactual placebo estimates. We used direct standardization via analysis weights to achieve the same distribution of person-years between the external study and HPTN 084, across strata predictive of HIV risk (country and selected risk covariates). We estimated prevention efficacy against a counterfactual placebo to provide information on the use of CAB-LA and FTC/TDF compared to no intervention. We compared the counterfactual placebo findings for FTC/TDF to previous placebo-controlled trials, adjusted for observed adherence to daily pills.

RESULTS

Distribution of age and baseline prevalence of gonorrhoea and chlamydia were similar among matched counterfactual placebo and observed HPTN 084 arms after standardization. Counterfactual estimates of CAB-LA versus placebo in all three settings showed a consistent risk reduction of 93%-94%, with lower bounds of the confidence intervals above 72%. Observed adherence (quantifiable tenofovir in plasma) in HPTN 084 was 54%-56%, and estimated efficacy of daily oral FTC/TDF against a counterfactual placebo was consistent with a predicted risk reduction of 39%-40% for this level of daily pill use.

CONCLUSIONS

Counterfactual placebo rates of HIV acquisition derived from external trial data in similar locations and time can be used to support estimates of placebo-based efficacy of a novel HIV prevention agent. External trial data must be standardized to be representative of the clinical trial cohort testing the novel HIV prevention agent, accounting for confounders.

Quantifying how single dose Ad26.COV2.S vaccine efficacy depends on Spike sequence features

It is of interest to pinpoint SARS-CoV-2 sequence features defining vaccine resistance. In the ENSEMBLE randomized, placebo-controlled phase 3 trial, estimated single-dose Ad26.COV2.S vaccine efficacy (VE) was 56% against moderate to severe-critical COVID-19. SARS-CoV-2 Spike sequences were measured from 484 vaccine and 1,067 placebo recipients who acquired COVID-19 during the trial. In Latin America, where Spike diversity was greatest, VE was significantly lower against Lambda than against Reference and against all non-Lambda variants [family-wise error rate (FWER) p < 0.05]. VE also differed by residue match vs. mismatch to the vaccine-strain residue at 16 amino acid positions (4 FWER p < 0.05; 12 q-value ≤ 0.20). VE significantly decreased with physicochemical-weighted Hamming distance to the vaccine-strain sequence for Spike, receptor-binding domain, N-terminal domain, and S1 (FWER p < 0.001); differed (FWER ≤ 0.05) by distance to the vaccine strain measured by 9 different antibody-epitope escape scores and by 4 NTD neutralization-impacting features; and decreased (p = 0.011) with neutralization resistance level to vaccine recipient sera. VE against severe-critical COVID-19 was stable across most sequence features but lower against viruses with greatest distances. These results help map antigenic specificity of in vivo vaccine protection.

Immunogenicity and reactogenicity of COVID-19 Pfizer-BioNTech (BNT162b2) mRNA vaccination in immunocompromised adolescents and young adults: a systematic review and meta-analyses

BACKGROUND

This study aimed to evaluate the safety and effectiveness of the BNT162b2 vaccine in immunocompromised adolescents and young adults.

RESEARCH DESIGN AND METHODS

The study conducted a meta-analysis of post-marketing studies examining BNT162b2 vaccination efficacy and safety among immunocompromised adolescents and young adults worldwide. The review included nine studies and 513 individuals aged between 12 and 24.3 years. The study used a random effect model to estimate pooled proportions, log relative risk, and mean difference, and assessed heterogeneity using the I2 test. The study also examined publication bias using Egger's regression and Begg's rank correlation and assessed bias risk using ROBINS-I.

RESULTS

The pooled proportions of combined local and systemic reactions after the first and second doses were 30% and 32%, respectively. Adverse events following immunization (AEFI) were most frequent in rheumatic diseases (40%) and least frequent in cystic fibrosis (27%), although hospitalizations for AEFIs were rare. The pooled estimations did not show a statistically significant difference between immunocompromised individuals and healthy controls for neutralizing antibodies, measured IgG, or vaccine effectiveness after the primary dose. However, the evidence quality is low to moderate due to a high risk of bias, and no study could rule out the risk of selection bias, ascertainment bias, or selective outcome reporting.

CONCLUSIONS

This study provides preliminary evidence that the BNT162b2 vaccine is safe and effective in immunocompromised adolescents and young adults, but with low to moderate evidence quality due to bias risk. The study calls for improved methodological quality in studies involving specific populations.

Upregulation of IFN-stimulated genes persists beyond the transitory broad immunologic changes of acute HIV-1 infection

Chronic immune activation during HIV-1 infection contributes to morbidity and mortality in people living with HIV. To elucidate the underlying biological pathways, we evaluated whole blood gene expression trajectories from before, through acute, and into chronic HIV-1 infection. Interferon-stimulated genes, including MX1, IFI27 and ISG15, were upregulated during acute infection, remained elevated into chronic infection, and were strongly correlated with plasma HIV-1 RNA as well as TNF-α and CXCL10 cytokine levels. In contrast, genes involved in cellular immune responses, such as CD8A, were upregulated during acute infection before reaching a peak and returning to near pre-infection levels in chronic infection. Our results indicate that chronic immune activation during HIV-1 infection is characterized by persistent elevation of a narrow set of interferon-stimulated genes and innate cytokines. These findings raise the prospect of devising a targeted intervention to restore healthy immune homeostasis in people living with HIV-1.

The Future of Epidemic and Pandemic Vaccines to Serve Global Public Health Needs

This Review initiates a wide-ranging discussion over 2023 by selecting and exploring core themes to be investigated more deeply in papers submitted to the Vaccines Special Issue on the "Future of Epidemic and Pandemic Vaccines to Serve Global Public Health Needs". To tackle the SARS-CoV-2 pandemic, an acceleration of vaccine development across different technology platforms resulted in the emergency use authorization of multiple vaccines in less than a year. Despite this record speed, many limitations surfaced including unequal access to products and technologies, regulatory hurdles, restrictions on the flow of intellectual property needed to develop and manufacture vaccines, clinical trials challenges, development of vaccines that did not curtail or prevent transmission, unsustainable strategies for dealing with variants, and the distorted allocation of funding to favour dominant companies in affluent countries. Key to future epidemic and pandemic responses will be sustainable, global-public-health-driven vaccine development and manufacturing based on equitable access to platform technologies, decentralised and localised innovation, and multiple developers and manufacturers, especially in low- and middle-income countries (LMICs). There is talk of flexible, modular pandemic preparedness, of technology access pools based on non-exclusive global licensing agreements in exchange for fair compensation, of WHO-supported vaccine technology transfer hubs and spokes, and of the creation of vaccine prototypes ready for phase I/II trials, etc. However, all these concepts face extraordinary challenges shaped by current commercial incentives, the unwillingness of pharmaceutical companies and governments to share intellectual property and know-how, the precariousness of building capacity based solely on COVID-19 vaccines, the focus on large-scale manufacturing capacity rather than small-scale rapid-response innovation to stop outbreaks when and where they occur, and the inability of many resource-limited countries to afford next-generation vaccines for their national vaccine programmes. Once the current high subsidies are gone and interest has waned, sustaining vaccine innovation and manufacturing capability in interpandemic periods will require equitable access to vaccine innovation and manufacturing capabilities in all regions of the world based on many vaccines, not just "pandemic vaccines". Public and philanthropic investments will need to leverage enforceable commitments to share vaccines and critical technology so that countries everywhere can establish and scale up vaccine development and manufacturing capability. This will only happen if we question all prior assumptions and learn the lessons offered by the current pandemic. We invite submissions to the special issue, which we hope will help guide the world towards a global vaccine research, development, and manufacturing ecosystem that better balances and integrates scientific, clinical trial, regulatory, and commercial interests and puts global public health needs first.

Homologous Ad26.COV2.S vaccination results in reduced boosting of humoral responses in hybrid immunity, but elicits antibodies of similar magnitude regardless of prior infection

The impact of previous SARS-CoV-2 infection on the durability of Ad26.COV2.S vaccine-elicited responses, and the effect of homologous boosting has not been well explored. We followed a cohort of healthcare workers for 6 months after receiving the Ad26.COV2.S vaccine and a further one month after they received an Ad26.COV2.S booster dose. We assessed longitudinal spike-specific antibody and T cell responses in individuals who had never had SARS-CoV-2 infection, compared to those who were infected with either the D614G or Beta variants prior to vaccination. Antibody and T cell responses elicited by the primary dose were durable against several variants of concern over the 6 month follow-up period, regardless of infection history. However, at 6 months after first vaccination, antibody binding, neutralization and ADCC were as much as 33-fold higher in individuals with hybrid immunity compared to those with no prior infection. Antibody cross-reactivity profiles of the previously infected groups were similar at 6 months, unlike at earlier time points suggesting that the effect of immune imprinting diminishes by 6 months. Importantly, an Ad26.COV2.S booster dose increased the magnitude of the antibody response in individuals with no prior infection to similar levels as those with previous infection. The magnitude of spike T cell responses and proportion of T cell responders remained stable after homologous boosting, concomitant with a significant increase in long-lived early differentiated CD4 memory T cells. Thus, these data highlight that multiple antigen exposures, whether through infection and vaccination or vaccination alone, result in similar boosts after Ad26.COV2.S vaccination.

Impact of Point-of-Care Testing on the Management of Sexually Transmitted Infections in South Africa: Evidence from the HVTN702 Human Immunodeficiency Virus Vaccine Trial

BACKGROUND

Alternative approaches to syndromic management are needed to reduce rates of sexually transmitted infections (STIs) in resource-limited settings. We investigated the impact of point-of-care (POC) versus central laboratory-based testing on STI treatment initiation and STI adverse event (STI-AE) reporting.

METHODS

We used Kaplan-Meier and Cox regression models to compare times to treatment initiation and STI-AE reporting among HVTN702 trial participants in South Africa. Neisseria gonorrhoeae (NG) and Chlamydia trachomatis (CT) were diagnosed POC at eThekwini clinic and in a central laboratory at Verulam/Isipingo clinics. All clinics used POC assays for Trichomonas vaginalis (TV) testing.

RESULTS

Among 959 women (median age, 23 [interquartile range, 21-26] years), median days (95% confidence interval [95%CI]) to NG/CT treatment initiation and NG/CT-AE reporting were 0.20 (.16-.25) and 0.24 (.19-.27) at eThekwini versus 14.22 (14.12-15.09) and 15.12 (13.22-21.24) at Verulam/Isipingo (all P < .001). Median days (95%CI) to TV treatment initiation and TV-AE reporting were 0.17 (.12-.27) and 0.25 (.20-.99) at eThekwini versus 0.18 (.15-.2) and 0.24 (.15-.99) at Verulam/Isipingo (all P > .05). Cox regression analysis revealed that NG/CT treatment initiation (adjusted hazard ratio [aHR], 39.62 [95%CI, 15.13-103.74]) and NG/CT-AE reporting (aHR, 3.38 [95%CI, 2.23-5.13]) occurred faster at eThekwini versus Verulam/Isipingo, while times to TV treatment initiation (aHR, 0.93 [95%CI, .59-1.48]) and TV-AE reporting (aHR, 1.38 [95%CI, .86-2.21]) were similar.

CONCLUSIONS

POC testing led to prompt STI management with potential therapeutic and prevention benefits, highlighting its utility as a diagnostic tool in resource-limited settings.

Pregnancy and neonatal safety outcomes of timing of initiation of daily oral tenofovir disoproxil fumarate and emtricitabine pre-exposure prophylaxis for HIV prevention (CAP016): an open-label, randomised, non-inferiority trial

BACKGROUND

The safety of tenofovir disoproxil fumarate and emtricitabine as pre-exposure prophylaxis (PrEP) in pregnant women not living with HIV is uncertain. We aimed to compare pregnancy and neonatal outcomes in women exposed and not exposed to PrEP during pregnancy.

METHODS

In this single-site, open-label, randomised, non-inferiority trial in Durban, South Africa, we evaluated pregnancy and neonatal outcomes in pregnant women aged 18 years or older, not living with HIV, and at 14-28 weeks' gestation at the time of enrolment. Eligible participants were randomly assigned (1:1) using a computer-generated permuted block (block size of ten) randomisation list to immediate initiation or deferred initiation of PrEP until breastfeeding cessation. Participants in the immediate PrEP group received a monthly supply of once daily oral tenofovir disoproxil fumarate 300 mg and emtricitabine 200 mg. Participants in the deferred PrEP group received standard of care for HIV prevention. The primary outcomes were the occurrence of preterm live birth (<37 weeks gestational age) and very preterm birth (<34 weeks gestational age) determined by menstrual dating, low birthweight (<2500 g), very low birthweight (<1500 g), stillbirth (≥20 weeks gestational age), and small for gestational age (birthweight less than the tenth percentile). Post-natal safety outcomes will be reported elsewhere. We used binomial regression models to estimate risk differences and two-sided 90% CIs. Immediate PrEP was non-inferior to deferred PrEP if the upper bound of the 90% CI of the risk difference was less than the upper predefined non-inferiority margin for preterm birth (7·5%), very preterm birth (2·6%), low birthweight (5·5%), very low birthweight (1·2%), stillbirth (1·0%), and small for gestational age (3·7%). All outcomes were analysed in the intention-to-treat population. This study is registered with ClinicalTrials.gov, NCT3227731.

FINDINGS

Between Sept 25, 2017, and Dec 6, 2019, we screened 693 women, of whom 540 were randomly assigned to immediate PrEP (n=271) or deferred PrEP (n=269). The median gestational age was 19 weeks (IQR 15-23 for immediate PrEP and 16-23 for deferred PrEP). The risk difference between the immediate PrEP group and the deferred PrEP group for preterm birth was -4·7% (90% CI -10·7 to 1·2; immediate PrEP was non-inferior), for very preterm birth was 0·6% (-3·4 to 4·6; upper limit exceeded the non-inferiority margin), for low birthweight was 2·5% (-1·6 to 6·6; upper limit exceeded the non-inferiority margin), for very low birthweight was 0% (-1·4 to 1·4; upper limit exceeded the non-inferiority margin), for stillbirth was 1·2% (-1·5 to 3·8; upper limit exceeded the non-inferiority margin), and for small for gestational age was 0·9% (-1·2 to 2·9; immediate PrEP was non-inferior).

INTERPRETATION

In our study, PrEP was not associated with preterm birth or small for gestational age infants. Our data support the use of tenofovir disoproxil fumarate and emtricitabine in pregnancy and our reassuring findings can be used to allay safety concerns among pregnant women.

FUNDING

South African Medical Research Council and Gilead Sciences.

Vascular thrombosis after single dose Ad26.COV2.S vaccine in healthcare workers in South Africa: open label, single arm, phase 3B study (Sisonke study)

Objective

To assess the rates of vascular thrombotic adverse events in the first 35 days after one dose of the Ad26.COV2.S vaccine (Janssen/Johnson & Johnson) in healthcare workers in South Africa and to compare these rates with those observed in the general population.

Design

Open label, single arm, phase 3B study.

Setting

Sisonke study, South Africa, 17 February to 15 June 2021.

Participants

The Sisonke cohort of 477 234 healthcare workers, aged ≥18 years, who received one dose of the Ad26.COV2.S vaccine.

Main outcome measures

Observed rates of venous arterial thromboembolism and vaccine induced immune thrombocytopenia and thrombosis in individuals who were vaccinated, compared with expected rates, based on age and sex specific background rates from the Clinical Practice Research Datalink GOLD database (database of longitudinal routinely collected electronic health records from UK primary care practices using Vision general practice patient management software).

Results

Most of the study participants were women (74.9%) and median age was 42 years (interquartile range 33-51). Twenty nine (30.6 per 100 000 person years, 95% confidence interval 20.5 to 44.0) vascular thrombotic events occurred at a median of 14 days (7-29) after vaccination. Of these 29 participants, 93.1% were women, median age 46 (37-55) years, and 51.7% had comorbidities. The observed to expected ratios for cerebral venous sinus thrombosis with thrombocytopenia and pulmonary embolism with thrombocytopenia were 10.6 (95% confidence interval 0.3 to 58.8) and 1.2 (0.1 to 6.5), respectively. Because of the small number of adverse events and wide confidence intervals, no conclusions were drawn between these estimates and the expected incidence rates in the population.

Conclusions

Vaccine induced immune thrombocytopenia and thrombosis after one dose of the Ad26.COV2.S vaccine was found in only a few patients in this South African population of healthcare workers. These findings are reassuring if considered in terms of the beneficial effects of vaccination against covid-19 disease. These data support the continued use of this vaccine, but surveillance is recommended to identify other incidences of venous and arterial thromboembolism and to improve confidence in the data estimates.

Trial registration

ClinicalTrials.govNCT04838795.

Wastewater-based SARS-CoV-2 airport surveillance: key trends at the Cape Town International Airport

Monitoring of SARS-CoV-2 RNA in wastewater has revealed the role of mobility in the transmission of coronavirus disease (COVID-19), and the surveillance of airport wastewater in cities across the world has demonstrated how travel entry points can give an indication of trends in transmission. This study undertook wastewater surveillance at the Cape Town International Airport (CTIA) to assess the use of a WBE approach to provide supplementary information on the presence of COVID-19 at a key air travel entry point in South Africa. Grab wastewater samples (n = 55) were collected from the CTIA wastewater pump station and analysed using quantitative real-time polymerase chain reaction (qRT-PCR) method. The study found a correlation between the wastewater data and clinical cases reported in the City of Cape Town during various time periods and during the peak of a COVID-19 wave. Highly elevated viral loads in the wastewater were observed at times there was increased mobility through the airport. The study also revealed elevated viral load levels at the airport despite the stricter restrictions and through the lower restrictions. The study findings indicate wastewater surveillance and airports can provide supplementary information to airport authorities to assess the impacts of imposed travel restrictions.

Upregulation of PTPRC and Interferon Response Pathways in HIV-1 Seroconverters Prior to Infection

Human immunodeficiency virus 1 (HIV-1) exposed seronegative (HESN) individuals may have unique characteristics that alter susceptibility to HIV-1 infection. However, identifying truly exposed HESN is challenging. We utilized stored data and biospecimens from HIV-1 serodifferent couple cohorts, in which couples' HIV-1 exposures were quantified based on unprotected sex frequency and viral load of the partner with HIV-1. We compared peripheral blood gene expression between 15 HESN and 18 seroconverters prior to infection. We found PTPRC (encoding CD45 antigen) and interferon-response pathways had significantly higher expression among individuals who went on to become seropositive and thus may be a signature for increased acquisition risk.

Association between regular physical activity and the protective effect of vaccination against SARS-CoV-2 in a South African case-control study

BACKGROUND

Both vaccination and physical activity have been shown to independently decrease the likelihood of severe COVID-19 infection.

OBJECTIVE

To assess the association between regular physical activity and vaccination against COVID-19 among healthcare workers.

METHODS

A test negative case-control study design was used to estimate the risk of having an associated COVID-19-related hospital admission, among individuals who were unvaccinated compared with those who were fully vaccinated with Ad26.COV2.S (>28 days after a single dose). 196 444 participant tests were stratified into three measured physical activity subgroups with low, moderate and high activity, to test the hypothesis that physical activity is an effect modifier on the relationship between vaccination and hospitalisation.

RESULTS

Vaccine effectiveness against a COVID-19-related admission among vaccinated individuals within the low activity group was 60.0% (95% CI 39.0 to 73.8), 72.1% (95% CI 55.2 to 82.6) for the moderate activity group, and 85.8% (95% CI 74.1 to 92.2) for the high activity group. Compared with individuals with low activity levels, vaccinated individuals with moderate and high activity levels had a 1.4 (95% CI 1.36 to 1.51) and 2.8 (95% CI 2.35 to 3.35) times lower risk of COVID-19 admission, respectively (p value <0.001 for both groups).

CONCLUSIONS

Regular physical activity was associated with improved vaccine effectiveness against COVID-19 hospitalisation, with higher levels of physical activity associated with greater vaccine effectiveness. Physical activity enhances vaccine effectiveness against severe COVID-19 outcomes and should be encouraged by greater public health messaging.

Novavax NVX-COV2373 triggers neutralization of Omicron sub-lineages

The SARS-CoV-2 Omicron (B.1.1.529) Variant of Concern (VOC) and its sub-lineages (including BA.2, BA.4, BA.5, BA.2.12.1) contain spike mutations that confer high level resistance to neutralizing antibodies induced by vaccination with ancestral spike or infection with previously circulating variants. The NVX-CoV2373 vaccine, a protein nanoparticle vaccine containing the ancestral spike sequence, has value in countries with constrained cold-chain requirements. Here we report neutralizing titers following two or three doses of NVX-CoV2373. We show that after two doses, Omicron sub-lineages BA.1 and BA.4/BA.5 were resistant to neutralization by 72% (21/29) and 59% (17/29) of samples respectively. However, after a third dose of NVX-CoV2373, we observed high titers against Omicron BA.1 (GMT: 1,197) and BA.4/BA.5 (GMT: 582), with responses similar in magnitude to those triggered by three doses of an mRNA vaccine. These data are of particular relevance as BA.4/BA.5 is dominating in multiple locations, and highlight the potential utility of the NVX-CoV2373 vaccine as a booster in resource-limited environments.

Using Wastewater Surveillance to Compare COVID-19 Outbreaks during the Easter Holidays over a 2-Year Period in Cape Town, South Africa

Wastewater surveillance of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has shown to be an important approach to determine early outbreaks of infections. Wastewater-based epidemiology (WBE) is regarded as a complementary tool for monitoring SARS-CoV-2 trends in communities. In this study, the changes in the SARS-CoV-2 RNA levels in wastewater during Easter holidays in 2021 and 2022 in the City of Cape Town were monitored over nine weeks. Our findings showed a statistically significant difference in the SARS-CoV-2 RNA viral load between the study weeks over the Easter period in 2021 and 2022, except for study week 1 and 4. During the Easter week, 52% of the wastewater treatment plants moved from the lower (low viral RNA) category in 2021 to the higher (medium to very high viral RNA) categories in 2022. As a result, the median SARS-CoV-2 viral loads where higher during the Easter week in 2022 than Easter week in 2021 (p = 0.0052). Mixed-effects model showed an association between the SARS-CoV-2 RNA viral loads and Easter week over the Easter period in 2021 only (p < 0.01). The study highlights the potential of WBE to track outbreaks during the holiday period.

Rapid Development of an Integrated Network Infrastructure to Conduct Phase 3 COVID-19 Vaccine Trials

Importance

The COVID-19 pandemic has caused millions of infections and deaths and resulted in unprecedented international public health social and economic crises. As SARS-CoV-2 spread across the globe and its impact became evident, the development of safe and effective vaccines became a priority. Outlining the processes used to establish and support the conduct of the phase 3 randomized clinical trials that led to the rapid emergency use authorization and approval of several COVID-19 vaccines is of major significance for current and future pandemic response efforts.

Observations

To support the rapid development of vaccines for the US population and the rest of the world, the National Institute of Allergy and Infectious Diseases established the COVID-19 Prevention Network (CoVPN) to assist in the coordination and implementation of phase 3 efficacy trials for COVID-19 vaccine candidates and monoclonal antibodies. By bringing together multiple networks, CoVPN was able to draw on existing clinical and laboratory infrastructure, community partnerships, and research expertise to quickly pivot clinical trial sites to conduct COVID-19 vaccine trials as soon as the investigational products were ready for phase 3 testing. The mission of CoVPN was to operationalize phase 3 vaccine trials using harmonized protocols, laboratory assays, and a single data and safety monitoring board to oversee the various studies. These trials, while staggered in time of initiation, overlapped in time and course of conduct and ultimately led to the successful completion of multiple studies and US Food and Drug Administration-licensed or -authorized vaccines, the first of which was available to the public less than 1 year from the discovery of the virus.

Conclusions and Relevance

This Special Communication describes the design, geographic distribution, and underlying principles of conduct of these efficacy trials and summarizes data from 136 382 prospectively followed-up participants, including more than 2500 with documented COVID-19. These successful efforts can be replicated for other important research initiatives and point to the importance of investments in clinical trial infrastructure integral to pandemic preparedness.

Impact of SARS-CoV-2 exposure history on the T cell and IgG response

Multiple severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) exposures, from infection or vaccination, can potently boost spike antibody responses. Less is known about the impact of repeated exposures on T cell responses. Here, we compare the prevalence and frequency of peripheral SARS-CoV-2-specific T cell and immunoglobulin G (IgG) responses in 190 individuals with complex SARS-CoV-2 exposure histories. As expected, an increasing number of SARS-CoV-2 spike exposures significantly enhances the magnitude of IgG responses, while repeated exposures improve the number of T cell responders but have less impact on SARS-CoV-2 spike-specific T cell frequencies in the circulation. Moreover, we find that the number and nature of exposures (rather than the order of infection and vaccination) shape the spike immune response, with spike-specific CD4 T cells displaying a greater polyfunctional potential following hybrid immunity compared with vaccination only. Characterizing adaptive immunity from an evolving viral and immunological landscape may inform vaccine strategies to elicit optimal immunity as the pandemic progress.

Participation in an HIV prevention intervention and access to and use of contraceptives among young women: A cross sectional analysis in six South African districts

OBJECTIVE

This study investigated whether young women's participation in a combination HIV-prevention intervention was associated with accessing and using condoms and other contraceptives.

STUDY DESIGN

A cross-sectional household survey was conducted from 2017 to 2018 among a representative sample of young women aged 15-24 years old living in six South African districts in which the intervention was implemented. Cross-tabulations and multivariate regression analyses of weighted data were performed to examine access to and use of condoms and other contraceptives.

RESULTS

In total 4399 young women participated, representing a 60.6% response rate. Of participants, 61.0% (n = 2685) reported accessing condoms and other contraceptives in the past year. Among those who ever had sex (n = 3009), 51.0% used condoms and 37.4% other contraceptives at last sex. Among 15-19 year old, participation in the combination intervention was positively associated with reporting contraceptive use other than condoms at last sex (Prevalence Ratio (PR): 1.36; 95% CI: 1.21-1.53) and reporting use of both condoms and other contraceptives at last sex (PR: 1.45; 95% CI: 1.26-1.68). No associations were observed in the age group 20-24.

CONCLUSION

Our findings suggest that combination HIV prevention interventions may lead to increased access and use of condoms and other methods of contraception among adolescent women, but this needs to be confirmed in experimental studies. We need to test different or more intensive interventions to increase contraceptive use in young women aged 20-24.

IMPLICATIONS

Participating in combination HIV prevention interventions that are delivered via multiple approaches may promote access to, and use of condoms and other methods of contraceptives among adolescent women, and thereby help reduce unintended pregnancies.

Safety of COVID-19 Pfizer-BioNtech (BNT162b2) mRNA vaccination in adolescents aged 12-17 years: A systematic review and meta-analysis

The COVID-19 pandemic has severely affected adolescents. Safe and effective vaccines are pivotal tools in controlling this pandemic. We reviewed the safety profile of the BNT162b2 COVID-19 vaccine in adolescents using mostly real-world data to assist decision-making. We used random-effects model meta-analysis to derive pooled rates of single or grouped adverse events following immunization (AEFI) after each primary and booster dose, as well as after combining all doses. Reporting on over one million participants with safety data were included. The most-reported local and systemic AEFIs were pain/swelling/erythema/redness and fatigue/headache/myalgia, respectively. AESIs were rarely reported but were more frequent after the second dose than they were after the first and the booster doses. Health impact was less common among adolescents after receiving BNT162b2 vaccine. Rare life-threatening AEFIs were reported across all doses in real-world studies. Our findings highlight the significance of enhancing national and regional vaccination programs to ensure public confidence.

HIV incidence estimation among female sex workers in South Africa: a multiple methods analysis of cross-sectional survey data

BACKGROUND

Although numerous studies have investigated HIV risk factors and shown high HIV prevalence among female sex workers in South Africa, no national HIV incidence estimate exists for this potentially important group for HIV transmission. We aimed to estimate HIV incidence among female sex workers in South Africa who could be accessed through sex worker programmes, and to refine and describe the methods that enabled analysis.

METHODS

This study was embedded in a cross-sectional national survey of female sex workers who were linked to sex worker programmes. We aimed to enrol 3000 female sex workers aged at least 18 years who had sold or transacted in sex in the preceding 6 months in 12 randomly selected districts of the 22 districts with sex worker programmes, ensuring coverage of all provinces of South Africa. Women who self-reported as current victims of human trafficking were excluded from enrolment. We used a multistep process to sample districts and then hotspots, and a chain referral method to recruit participants. We collected cross-sectional data for self-reported HIV status, demographic characteristics, and exposure to violence. Two rapid tests were used to ascertain diagnostic markers, a viral load assay was used to ascertain clinical markers, and the Maxim Limiting Antigen Avidity EIA was used to ascertain infection-staging HIV markers. Given the challenges of estimating HIV incidence, especially cross-sectionally, multiple methods of estimation were adapted to our setting, leveraging the age structure of HIV prevalence, recency-of -infection biomarker results (ie, where recent infection is classified as ≤1·5 normalised optical density [ODn] on the avidity assay and viral load of ≥1000 copies per mL), and reported testing histories.

FINDINGS

Of 3005 female sex workers who were enrolled and interviewed between Feb 4 and June 26, 2019, 2999 who had HIV test results were included in this analysis. The median age of participants was 32 years (IQR 27-38). 1714 (57·2%) of 2999 participants self-reported as being HIV positive, and 1447 (48·3%) of 2993 participants reported client sexual violence in the past year. The measured HIV prevalence was 62·1% (95% CI 60·3-65·7) and peaked at approximately age 40 years. Using recency-of-infection biomarker results, we obtained a base case estimate of HIV incidence of 4·60 cases per 100 person-years (95% CI 1·53-8·45) for the population. Estimates were generally consistent by method, and outlying incidence estimates calculated by self-reported testing histories were considered unreliable. Various sensitivity analyses produced estimates up to 11 cases per 100 person-years, and we did not detect differences by age and region.

INTERPRETATION

We found that female sex workers have extraordinarily high HIV incidence of approximately 5 cases per 100 person-years, emphasising the need to sustain and strengthen efforts to mitigate risk and provide adequate care. The notable role that sex work has in HIV transmission demands substantial investment in ongoing epidemiological monitoring.

FUNDING

South African Medical Research Council, South African National Treasury, Global Fund, South African Department of Science and Innovation, Wellcome Trust.

The HIV Cascade of Care and Service Utilisation at Sex Work Programmes Among Female Sex Workers in South Africa

Female sex workers (FSWs) in South Africa experience a uniquely high prevalence of HIV. We describe the HIV cascade of care (CoC) in FSWs in South Africa, and explored service utilisation at sex work programmes. A cross-sectional, study enrolled FSWs across 12 sites in South Africa. Participants were recruited using chain-referral method. Inclusion criteria: ≥ 18 years, cis-gender female, sold/transacted in sex, HIV positive. 1862 HIV positive FSWs were enrolled. 92% were known positive, 87% were on antiretroviral treatment (ART). Of those on ART, 74% were virally suppressed. Younger FSWs were significantly less likely to be on ART or virally suppressed. Female sex workers using HIV services from specialised programs were 1.4 times more likely to be virally suppressed than non-program users. The pre-COVID-19 pandemic HIV CoC amongst FSWs in South Africa shows striking improvement from previous estimates, and approaches achievement of 90:90:90 goals.

Delineating the spread and prevalence of SARS-CoV-2 Omicron sub-lineages (BA.1- BA.5) and Deltacron using wastewater in the Western Cape, South Africa

This study was one of the first to detect Omicron sublineages BA.4 and BA.5 in wastewater from South Africa. Spearman rank correlation analysis confirmed a strong positive correlation between severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral RNA in wastewater samples and clinical cases (r = 0.7749, P < .0001). SARS-CoV-2 viral load detected in wastewater, resulting from the Delta-driven third wave, was significantly higher than during the Omicron-driven fourth wave. Whole-genome sequencing confirmed presence of Omicron lineage defining mutations in wastewater with the first occurrence reported 23 November 2021 (BA.1 predominant). The variant spread rapidly, with prevalence of Omicron-positive wastewater samples rising to >80% by 10 January 2022 with BA.2 as the predominant sublineage by 10 March 2022, whilst on 18 April 2022 BA.4 and BA.5 were detected in selected wastewater sites. These findings demonstrate the value of wastewater-based epidemiology to monitor the spatiotemporal spread and potential origin of new Omicron sublineages.

715 Implementation of Enhanced Recovery After Surgery (ERAS) in Total Laryngectomies

Aim

The Enhanced Recovery After Surgery (ERAS) protocol for total laryngectomies was first implemented in our tertiary head and neck centre from November 2019. It includes pre-operative carbohydrate loading and an early swallow test which facilitates recommencement of oral intake to improve outcomes. Protocol adherence rate and patient outcomes were measured to determine the effectiveness and benefits of ERAS in laryngectomy patients.

Method

22 total laryngectomy patients from November 2019 to September 2021 were enrolled onto the ERAS protocol, 18 primary and 3 salvage cases. An analysis of the respective patient cohorts was performed to determine adherence to the ERAS protocol and outcomes such as complications and length of inpatient stay were measured.

Results

19 patients (86%) received pre-operative carbohydrate loading successfully, while 3 patients were contraindicated due to background of diabetes. Early swallow test was performed in 59% of patients. Potential reasons for delay were stoma dehiscence or clinical suspicion of neo-pharyngeal leak. 59% of primary cases were deemed medically fit for discharge within the target timeframe of 12–14 days whereas no target was set for salvage cases due to expected poor healing. Main complication in primary cases was neo-pharyngeal leak followed by stoma dehiscence with 28% and 11% respectively.

Conclusion

Limitations of our study include small sample size due to the COVID-19 pandemic. Despite its infancy, the ERAS protocol has achieved good outcomes in early recommencement of oral intake post-laryngectomy and encouraging early safe discharge from hospital. Future plans include establishment of Prehab Clinic and application of ERAS to neck dissection patients.

Omicron infection enhances Delta antibody immunity in vaccinated persons

The extent to which Omicron infection1-9, with or without previous vaccination, elicits protection against the previously dominant Delta (B.1.617.2) variant is unclear. Here we measured the neutralization capacity against variants of severe acute respiratory syndrome coronavirus 2 in 39 individuals in South Africa infected with the Omicron sublineage BA.1 starting at a median of 6 (interquartile range 3-9) days post symptom onset and continuing until last follow-up sample available, a median of 23 (interquartile range 19-27) days post symptoms to allow BA.1-elicited neutralizing immunity time to develop. Fifteen participants were vaccinated with Pfizer's BNT162b2 or Johnson & Johnson's Ad26.CoV2.S and had BA.1 breakthrough infections, and 24 were unvaccinated. BA.1 neutralization increased from a geometric mean 50% focus reduction neutralization test titre of 42 at enrolment to 575 at the last follow-up time point (13.6-fold) in vaccinated participants and from 46 to 272 (6.0-fold) in unvaccinated participants. Delta virus neutralization also increased, from 192 to 1,091 (5.7-fold) in vaccinated participants and from 28 to 91 (3.0-fold) in unvaccinated participants. At the last time point, unvaccinated individuals infected with BA.1 had low absolute levels of neutralization for the non-BA.1 viruses and 2.2-fold lower BA.1 neutralization, 12.0-fold lower Delta neutralization, 9.6-fold lower Beta variant neutralization, 17.9-fold lower ancestral virus neutralization and 4.8-fold lower Omicron sublineage BA.2 neutralization relative to vaccinated individuals infected with BA.1. These results indicate that hybrid immunity formed by vaccination and Omicron BA.1 infection should be protective against Delta and other variants. By contrast, infection with Omicron BA.1 alone offers limited cross-protection despite moderate enhancement.

Gender, Power, and Health: Measuring and Assessing Sexual Relationship Power Equity Among Young Sub-Saharan African Women and Men, a Systematic Review

Gender inequity, including low sexual relationship power (SRP), is an important determinant of intimate partner violence (IPV) and negative sexual, reproductive, and mental health. Different versions of the Sexual Relationship Power Scale (SRPS) are commonly used within youth studies to examine how gender inequities, including controlling behaviors, in heterosexual relationships impact the lives of young people in sub-Saharan Africa. This review aims to (1) describe definitions and measures of SRP within sub-Saharan African youth studies and (2) review and summarize associations between SRP equity, IPV, and sexual, reproductive, and mental health. After searching Pubmed, Ovid Med, Psych info, Web of Science, Google Scholar, and relevant research forums, 304 papers were identified, of which 29 papers based on 15 distinct studies (published 2004-2019) met our criteria for being youth-specific, conducted in sub-Saharan Africa, and including a quantitative measure of SRP. Details of each SRPS are described, including any adaptations and psychometric properties, as well as associations with IPV, sexual, reproductive, and mental health behaviors and outcomes. Results indicate that there are variations to the SRPS, and a paucity of evidence has detailed the psychometric properties of such measures within sub-Saharan African youth studies. Measures of SRP equity are associated with experiences (among women) and perpetration of (among men) IPV as numerous pathways to HIV risk; however, the evidence remains mixed. In order to address overlapping epidemics of violence against women and HIV, efforts are needed to ensure that measures, including the SRPS, are valid and reliable among highly affected populations.

Safety evaluation of the single-dose Ad26.COV2.S vaccine among healthcare workers in the Sisonke study in South Africa: A phase 3b implementation trial

BACKGROUND

Real-world evaluation of the safety profile of vaccines after licensure is crucial to accurately characterise safety beyond clinical trials, support continued use, and thereby improve public confidence. The Sisonke study aimed to assess the safety and effectiveness of the Janssen Ad26.COV2.S vaccine among healthcare workers (HCWs) in South Africa. Here, we present the safety data.

METHODS AND FINDINGS

In this open-label phase 3b implementation study among all eligible HCWs in South Africa registered in the national Electronic Vaccination Data System (EVDS), we monitored adverse events (AEs) at vaccination sites through self-reporting triggered by text messages after vaccination, healthcare provider reports, and active case finding. The frequency and incidence rate of non-serious and serious AEs were evaluated from the day of first vaccination (17 February 2021) until 28 days after the final vaccination in the study (15 June 2021). COVID-19 breakthrough infections, hospitalisations, and deaths were ascertained via linkage of the electronic vaccination register with existing national databases. Among 477,234 participants, 10,279 AEs were reported, of which 138 (1.3%) were serious AEs (SAEs) or AEs of special interest. Women reported more AEs than men (2.3% versus 1.6%). AE reports decreased with increasing age (3.2% for age 18-30 years, 2.1% for age 31-45 years, 1.8% for age 46-55 years, and 1.5% for age > 55 years). Participants with previous COVID-19 infection reported slightly more AEs (2.6% versus 2.1%). The most common reactogenicity events were headache (n = 4,923) and body aches (n = 4,483), followed by injection site pain (n = 2,767) and fever (n = 2,731), and most occurred within 48 hours of vaccination. Two cases of thrombosis with thrombocytopenia syndrome and 4 cases of Guillain-Barré Syndrome were reported post-vaccination. Most SAEs and AEs of special interest (n = 138) occurred at lower than the expected population rates. Vascular (n = 37; 39.1/100,000 person-years) and nervous system disorders (n = 31; 31.7/100,000 person-years), immune system disorders (n = 24; 24.3/100,000 person-years), and infections and infestations (n = 19; 20.1/100,000 person-years) were the most common reported SAE categories. A limitation of the study was the single-arm design, with limited routinely collected morbidity comparator data in the study setting.

CONCLUSIONS

We observed similar patterns of AEs as in phase 3 trials. AEs were mostly expected reactogenicity signs and symptoms. Furthermore, most SAEs occurred below expected rates. The single-dose Ad26.COV2.S vaccine demonstrated an acceptable safety profile, supporting the continued use of this vaccine in this setting.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04838795; Pan African Clinical Trials Registry PACTR202102855526180.

Randomised trials of COVID-19 vaccines in Africa – charting the path forward

Vaccines have played a critical role in controlling disease outbreaks, hence the proliferation of the development and testing of multiple vaccine candidates during the COVID-19 pandemic. Randomised trials are gold standards for evaluating the safety and efficacy of pharmaceutical interventions such as COVID-19 vaccines. However, contextual differences may attenuate effects of COVID-19 vaccines. Thus, the need to conduct COVID-19 vaccine trials in all settings, including in Africa. We conducted a cross-sectional analysis of planned, ongoing, and completed COVID-19 vaccine trials in Africa. We searched the South African National Clinical Trials Register, Pan African Clinical Trials Registry, and International Clinical Trials Registry Platform (ICTRP) on 12 January and 30 April 2022; and complemented this with a search of ClinicalTrials.gov on 17 May 2022. We screened the search output and included randomised trials with at least one recruitment site in Africa. We identified only 108 eligible trials: 90 (83%) evaluating candidate COVID-19 vaccines, 11 (10%) assessing if existing vaccines could prevent SARS-CoV-2 infection, and 7 (7%) evaluating interventions for improving COVID-19 vaccination coverage. South Africa had the highest number of trials at 58 (54%). Beyond South Africa, countries with more than 10 trial sites include Kenya, Ghana, Egypt, Uganda, and Zimbabwe. Among the trials, 14 (13%) do not have principal investigators based in Africa, 39 (30%) are funded by industry, and 91 (84%) are funded by institutions based outside the host country. COVID-19 vaccine trials with recruitment sites in Africa represented only 7% of the 1453 COVID-19 vaccine trials in the ICTRP. The paucity of COVID-19 vaccine trials conducted on the African continent is a cause for concern. This has implications for the role that Africa may play in future pandemics.

Understanding Repeat Positive HIV Testing in South Africa Under Changing Treatment Guidelines

Some people with HIV (PWH) test positive multiple times without initiating antiretroviral therapy (ART). We surveyed 496 ART-eligible PWH following routine HIV testing at three clinics in Soweto and Gugulethu, South Africa in 2014-2015. Among repeat positive testers (RPTs) in this cohort, we compared rates of treatment initiation by prior treatment eligibility and assessed psychosocial predictors of treatment initiation in logistic regression models. RPTs represented 33.8% of PWH in this cohort. Less than half of those who reported eligibility for ART on prior testing started treatment upon retesting, in contrast to two thirds of RPTs who were previously ineligible for treatment who started treatment once they learned of their eligibility. Those who reported coping through substance use were more likely to decline treatment versus those not using substances. PWH who test repeatedly represent a vulnerable population at risk for ART non-initiation who may benefit from interventions addressing individualized coping strategies.

Impact of preexisting anti-Ad26 humoral immunity on immunogenicity of the Ad26.COV2.S COVID-19 vaccine

This secondary analysis of the phase 3 ENSEMBLE trial (NCT04505722) assessed the impact of preexisting humoral immunity to adenovirus type 26 (Ad26) on the immunogenicity of Ad26.COV2.S-elicited SARS-CoV-2–specific antibody levels in 380 participants in Brazil, South Africa, and the United States. Among those vaccinated in Brazil and South Africa, 31% and 66%, respectively, had prevaccination serum-neutralizing activity against Ad26, with little preexisting immunity detected in the United States. Vaccine recipients in each country had similar post-vaccination spike-binding antibody levels, indicating that baseline immunity to Ad26 has no clear impact on vaccine-induced immune responses.

Sex work and young women: a cross sectional study to understand the overlap of age and sex work as a central tenet to epidemic control in South Africa

Adolescent girls and young women (AGYW) engaging in sex-for-money transactions are at risk of HIV infection. A better understanding of the demographic, socio-economic factors and risks of HIV acquisition is required to guide appropriate public health interventions targeting young sex workers in South Africa. A cross-sectional survey of Female Sex Workers (FSWs), using a chain referral sampling method, was conducted across 12 sites in South Africa in 2019. Three thousand and five participants were enrolled and interviewed assessing demographic characteristics, sexual behaviour, substance use and HIV testing and treatment. Of 3005 women, 13.3% were ≤24 years old (young FSWs); of these, 60.0% entered sex work aged ≤19 years. Economic factors were the primary drivers of entry into sex work. HIV prevalence amongst young FSWs was 40.4%, with 12.4% recently infected. Younger FSWs were significantly less likely to know they were HIV positive (87.6% versus 92.1%), to report any ART exposure (75.2% versus 87.6%) and to be virally suppressed (58.1% versus 75.2%) compared to older FSWs. Our findings highlight that many FSWs enter sex work at a young age. It is essential to develop tailored services and interventions that improve access to HIV prevention and treatment services addressing specific needs.

Final Analysis of Efficacy and Safety of Single-Dose Ad26.COV2.S

BACKGROUND

The Ad26.COV2.S vaccine was highly effective against severe-critical coronavirus disease 2019 (Covid-19), hospitalization, and death in the primary phase 3 efficacy analysis.

METHODS

We conducted the final analysis in the double-blind phase of our multinational, randomized, placebo-controlled trial, in which adults were assigned in a 1:1 ratio to receive single-dose Ad26.COV2.S (5×1010 viral particles) or placebo. The primary end points were vaccine efficacy against moderate to severe-critical Covid-19 with onset at least 14 days after administration and at least 28 days after administration in the per-protocol population. Safety and key secondary and exploratory end points were also assessed.

RESULTS

Median follow-up in this analysis was 4 months; 8940 participants had at least 6 months of follow-up. In the per-protocol population (39,185 participants), vaccine efficacy against moderate to severe-critical Covid-19 at least 14 days after administration was 56.3% (95% confidence interval [CI], 51.3 to 60.8; 484 cases in the vaccine group vs. 1067 in the placebo group); at least 28 days after administration, vaccine efficacy was 52.9% (95% CI, 47.1 to 58.1; 433 cases in the vaccine group vs. 883 in the placebo group). Efficacy in the United States, primarily against the reference strain (B.1.D614G) and the B.1.1.7 (alpha) variant, was 69.7% (95% CI, 60.7 to 76.9); efficacy was reduced elsewhere against the P.1 (gamma), C.37 (lambda), and B.1.621 (mu) variants. Efficacy was 74.6% (95% CI, 64.7 to 82.1) against severe-critical Covid-19 (with only 4 severe-critical cases caused by the B.1.617.2 [delta] variant), 75.6% (95% CI, 54.3 to 88.0) against Covid-19 leading to medical intervention (including hospitalization), and 82.8% (95% CI, 40.5 to 96.8) against Covid-19-related death, with protection lasting 6 months or longer. Efficacy against any severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection was 41.7% (95% CI, 36.3 to 46.7). Ad26.COV2.S was associated with mainly mild-to-moderate adverse events, and no new safety concerns were identified.

CONCLUSIONS

A single dose of Ad26.COV2.S provided 52.9% protection against moderate to severe-critical Covid-19. Protection varied according to variant; higher protection was observed against severe Covid-19, medical intervention, and death than against other end points and lasted for 6 months or longer. (Funded by Janssen Research and Development and others; ENSEMBLE ClinicalTrials.gov number, NCT04505722.).