Pre-vaccination frequency of circulatory Tfh is associated with robust immune response to TV003 dengue vaccine

It has been estimated that more than 390 million people are infected with Dengue virus every year; around 96 millions of these infections result in clinical pathologies. To date, there is only one licensed viral vector-based Dengue virus vaccine CYD-TDV approved for use in dengue endemic areas. While initially approved for administration independent of serostatus, the current guidance only recommends the use of this vaccine for seropositive individuals. Therefore, there is a critical need for investigating the influence of Dengue virus serostatus and immunological mechanisms that influence vaccine outcome. Here, we provide comprehensive evaluation of sero-status and host immune factors that correlate with robust immune responses to a Dengue virus vector based tetravalent vaccine (TV003) in a Phase II clinical cohort of human participants. We observed that sero-positive individuals demonstrate a much stronger immune response to the TV003 vaccine. Our multi-layered immune profiling revealed that sero-positive subjects have increased baseline/pre-vaccination frequencies of circulating T follicular helper (cTfh) cells and the Tfh related chemokine CXCL13/BLC. Importantly, this baseline/pre-vaccination cTfh profile correlated with the vaccinees' ability to launch neutralizing antibody response against all four sero-types of Dengue virus, an important endpoint for Dengue vaccine clinical trials. Overall, we provide novel insights into the favorable cTfh related immune status that persists in Dengue virus sero-positive individuals that correlate with their ability to mount robust vaccine specific immune responses. Such detailed interrogation of cTfh cell biology in the context of clinical vaccinology will help uncover mechanisms and targets for favorable immuno-modulatory agents.

Impact of distinct therapies on antibody response to SARS-CoV-2 vaccine in systemic lupus erythematosus

Objective

To date, the only study that has assessed the severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2 mRNA) vaccine in systemic lupus erythematosus (SLE) observed a moderate response, but the sample size precluded an accurate analysis of the effect of individual drugs. Therefore, we evaluated the immunogenicity of an inactivated SARS‐CoV‐2 vaccine (Sinovac‐CoronaVac) and the influence of different medications in SLE. Safety was also assessed.

Methods

We conducted a prospective controlled study of 232 SARS‐CoV‐2–naive SLE patients and 58 SARS‐CoV‐2–naive controls who were vaccinated with 2 doses of Sinovac‐CoronaVac with a 28‐day interval (day 0/day 28 [D0/D28]). Immunogenicity analysis at D0/D28 and D69 included anti‐SARS‐CoV‐2 S1/S2 IgG seroconversion (SC) and neutralizing antibodies (NAb) positivity. The influence of individual drugs on immune response and safety was assessed.

Results

Patients and controls were well balanced for age (P = 0.771). At D69, SLE patients showed a moderate SC (70.2% versus 98.1%; P < 0.001) and moderate frequency of NAb positivity (61.5% versus 84.6%; P = 0.002), although both frequencies were lower than in controls. Factors associated with lower SC in univariate analysis at D69 were prednisone use (odds ratio [OR] 0.215 [95% confidence interval (95% CI) 0.108–0.427], P < 0.001) and mycophenolate mofetil (MMF) use (OR 0.201 [95% CI 0.107–0.378], P < 0.001), whereas hydroxychloroquine (HCQ) use led to a 2.5 increase in SC (P = 0.011). SLE patients who were receiving HCQ monotherapy had similar SC to controls at D69 (100% versus 98.1%; P = 1.000). In multivariate analysis, prednisone and MMF use were independently associated with lower SC (P < 0.001) and NAb positivity (P < 0.001). Safety analysis revealed no moderate/severe adverse events.

Conclusion

Sinovac‐CoronaVac has a moderate immunogenicity in SARS‐CoV‐2–naive SLE patients with an excellent safety profile. We further demonstrate that HCQ may improve SC, whereas prednisone and MMF had a major deleterious effect in vaccine response, reinforcing the need to investigate the role of temporary MMF withdrawal or a vaccine‐booster dose (ClinicalTrials.gov identifier: NCT04754698).

Implications of a highly divergent dengue virus strain for cross-neutralization, protection, and vaccine immunity

Although divergent dengue viruses (DENVs) have been isolated in insects, nonhuman primates, and humans, their relationships to the four canonical serotypes (DENV 1-4) are poorly understood. One virus isolated from a dengue patient, DKE-121, falls between genotype and serotype levels of sequence divergence to DENV-4. To examine its antigenic relationship to DENV-4, we assessed serum neutralizing and protective activity. Whereas DENV-4-immune mouse sera neutralize DKE-121 infection, DKE-121-immune sera inhibit DENV-4 less efficiently. Passive transfer of DENV-4 or DKE-121-immune sera protects mice against homologous, but not heterologous, DENV-4 or DKE-121 challenge. Antigenic cartography suggests that DENV-4 and DKE-121 are related but antigenically distinct. However, DENV-4 vaccination confers protection against DKE-121 in nonhuman primates, and serum from humans immunized with a tetravalent vaccine neutralize DENV-4 and DKE-121 infection equivalently. As divergent DENV strains, such as DKE-121, may meet criteria for serotype distinction, monitoring their capacity to impact dengue disease and vaccine efficacy appears warranted.

Immunogenicity and safety of the CoronaVac inactivated vaccine in patients with autoimmune rheumatic diseases: a phase 4 trial

CoronaVac, an inactivated SARS-CoV-2 vaccine, has been approved for emergency use in several countries. However, its immunogenicity in immunocompromised individuals has not been well established. We initiated a prospective phase 4 controlled trial (no. NCT04754698, CoronavRheum) in 910 adults with autoimmune rheumatic diseases (ARD) and 182 age- and sex-frequency-matched healthy adults (control group, CG), who received two doses of CoronaVac. The primary outcomes were reduction of ≥15% in both anti-SARS-CoV-2 IgG seroconversion (SC) and neutralizing antibody (NAb) positivity 6 weeks (day 69 (D69)) after the second dose in the ARD group compared with that in the CG. Secondary outcomes were IgG SC and NAb positivity at D28, IgG titers and neutralizing activity at D28 and D69 and vaccine safety. Prespecified endpoints were met, with lower anti-SARS-Cov-2 IgG SC (70.4 versus 95.5%, P < 0.001) and NAb positivity (56.3 versus 79.3%, P < 0.001) at D69 in the ARD group than in the CG. Moreover, IgG titers (12.1 versus 29.7, P < 0.001) and median neutralization activity (58.7 versus 64.5%, P = 0.013) were also lower at D69 in patients with ARD. At D28, patients with ARD presented with lower IgG frequency (18.7 versus 34.6%, P < 0.001) and NAb positivity (20.6 versus 36.3%, P < 0.001) than that of the CG. There were no moderate/severe adverse events. These data support the use of CoronaVac in patients with ARD, suggesting reduced but acceptable short-term immunogenicity. The trial is still ongoing to evaluate the long-term effectiveness/immunogenicity.

Cabotegravir for HIV Prevention in Cisgender Men and Transgender Women

BACKGROUND

Safe and effective long-acting injectable agents for preexposure prophylaxis (PrEP) for human immunodeficiency virus (HIV) infection are needed to increase the options for preventing HIV infection.

METHODS

We conducted a randomized, double-blind, double-dummy, noninferiority trial to compare long-acting injectable cabotegravir (CAB-LA, an integrase strand-transfer inhibitor [INSTI]) at a dose of 600 mg, given intramuscularly every 8 weeks, with daily oral tenofovir disoproxil fumarate-emtricitabine (TDF-FTC) for the prevention of HIV infection in at-risk cisgender men who have sex with men (MSM) and in at-risk transgender women who have sex with men. Participants were randomly assigned (1:1) to receive one of the two regimens and were followed for 153 weeks. HIV testing and safety evaluations were performed. The primary end point was incident HIV infection.

RESULTS

The intention-to-treat population included 4566 participants who underwent randomization; 570 (12.5%) identified as transgender women, and the median age was 26 years (interquartile range, 22 to 32). The trial was stopped early for efficacy on review of the results of the first preplanned interim end-point analysis. Among 1698 participants from the United States, 845 (49.8%) identified as Black. Incident HIV infection occurred in 52 participants: 13 in the cabotegravir group (incidence, 0.41 per 100 person-years) and 39 in the TDF-FTC group (incidence, 1.22 per 100 person-years) (hazard ratio, 0.34; 95% confidence interval, 0.18 to 0.62). The effect was consistent across prespecified subgroups. Injection-site reactions were reported in 81.4% of the participants in the cabotegravir group and in 31.3% of those in the TDF-FTC group. In the participants in whom HIV infection was diagnosed after exposure to CAB-LA, INSTI resistance and delays in the detection of HIV infection were noted. No safety concerns were identified.

CONCLUSIONS

CAB-LA was superior to daily oral TDF-FTC in preventing HIV infection among MSM and transgender women. Strategies are needed to prevent INSTI resistance in cases of CAB-LA PrEP failure. (Funded by the National Institute of Allergy and Infectious Diseases and others; HPTN 083 ClinicalTrials.gov number, NCT02720094.).

Factors associated with self-reported adherence to daily oral pre-exposure prophylaxis among men who have sex with man and transgender women: PrEP Brasil study

Understanding the factors associated with pre-exposure prophylaxis (PrEP) adherence may help in the development of strategies to support, motivate and sustain PrEP use. This study estimated self-reported adherence, described perceived barriers and facilitators and investigated factors associated with adherence to daily oral PrEP among men who have sex with man (MSM) and transgender women after 1 year of PrEP use in Brazil. PrEP Brasil was a prospective, multicentre, open-label demonstration study with MSM and transgender women at high risk for HIV infection. We used logistic regression to evaluate factors associated with complete adherence (not forgetting to take any pills in the past 30 days) at week 48. Of 338 participants included in this analysis, 60% reported complete adherence to daily oral PrEP at week 48. Perceived barriers and facilitators to daily oral PrEP were reported by 38.2% and 98.5%, respectively. The most reported barrier and facilitator were 'I forgot to take my pills' (19.2%) and 'Associate PrEP with a daily activity/task' (58.6%), respectively. In final multivariable analysis, living in Rio de Janeiro (aOR: 0.38; 95% CI: 0.20-0.73), being transgender women (aOR: 0.22; 95% CI: 0.07-0.73), reporting stimulant use (a OR: 0.40; 95% CI: 0.20-0.80) and having any perceived barriers to daily oral PrEP (aOR: 0.12; 95% CI: 0.07-0.23) were associated with decreased odds of complete adherence. Our findings provide information for developing the best practices to promote PrEP adherence in the Brazilian context.

Possible risk compensation, attitudes, and beliefs among Brazilian individuals potentially eligible for pre-exposure prophylaxis

Pre-exposure prophylaxis (PrEP) prevents HIV infection among men who have sex with men (MSM) and transgender women (TGW) who are the groups that presents the high incidence risk in Brazil. This cross-sectional secondary analysis describes possible risk compensation, attitudes, and beliefs regarding the use of PrEP among 723 MSM and TGW evaluated in the PrEP Brazil study pre-screening phase. Possible risk compensation was reported by 31.6% individuals. In the multivariate model, factors that increased the likelihood of possible risk compensation were: self-referring as white vs. Black (AOR 2.05; CI 1.09, 3.85), perceiving high likelihood of getting HIV in next 12 months (AOR 1.78; CI 1.23, 2.56), being less afraid of HIV infection if using PrEP (AOR 1.93; CI 1.19, 3.14), feeling liberated to have more partners if using PrEP (AOR 2.93; CI 1.92, 4.49), and believing closest friends would use PrEP (AOR 2.51; CI 1.1, 5.71). We found that possible risk compensation was more common among individuals who presented high-risk perception for HIV infection, probably reflecting they feel at risk and could benefit from PrEP use.

Radiological patterns of incidental epididymitis in mild-to-moderate COVID-19 patients revealed by colour Doppler ultrasound

The testis is a potential target organ for SARS-CoV-2 infection. Our study intended to investigate any testicular involvement in mild-to-moderate COVID-19 men. We conduct a cross-sectional study in 18 to 55-year-old men hospitalised for confirmed COVID-19. A senior radiologist executed the ultrasound with multi-frequency linear probe in all participants, regardless of any scrotal complaints. Exclusion criteria involved any situation that could impair testicular function. Statistical analysis compared independent groups, classified by any pathological change. Categorical and numerical outcome hypotheses were tested by Fisher's Exact and Mann-Whitney tests, using the Excel for Mac, version 16.29 (p < .05). The sample size was 26 men (mean 33.7 ± 6.2 years; range: 21-42 years), all without scrotal complaints. No orchitis was seen. Eleven men (32.6 ± 5.8 years) had epididymitis (42.3%), bilateral in 19.2%. More than half of men with epididymitis displayed epididymal head augmentation > 1.2 cm (p = .002). Two distinct epididymitis' patterns were reported: (a) disseminated micro-abscesses (n = 6) and (b) inhomogeneous echogenicity with reactional hydrocele (n = 5). Both patterns revealed increased epididymal head, augmented Doppler flow and scrotal skin thickening. The use of colour Doppler ultrasound in mild-to-moderate COVID-19 men, even in the absence of testicular complaints, might be useful to diagnose epididymitis that could elicit fertility complications.

Association between circulating exhausted CD4+ T cells with poor meningococcal C conjugate vaccine antibody response in HIV-infected children and adolescents

OBJECTIVES

To investigate the expression levels of surface markers of activation (CD38 and HLA-DR), inhibition (PD-1, TIGIT and CD57) and co-stimulation (CD28 and CD127) on CD4+ T cells of children/adolescents with vertical HIV infection (HI patients) and HIV-uninfected (HU) controls vaccinated with the meningococcal C conjugate vaccine (MCC).

METHODS

HI patients (n=12), aged 8-17 years, were immunized with two MCC injections, while HU controls (n=9), aged 5.3-10.7 years, received a single MCC dose (as per national recommendation at the time of this study, a single MCC vaccine dose should be given for healthy children and youth aged 1-18 years). The HI patients were categorized according to the combined antiretroviral therapy (cART) treatment. Blood samples were obtained before vaccination, after priming, and after the administration of a booster dose of vaccine to determine the serum bactericidal antibody (SBA) titers and the expression levels of surface markers on CD4+ T cells by flow cytometry. The levels of serum cytokines, IL-4 and CXCL-13 were also measured using Luminex kits.

RESULTS

The co-expression of the TIGIT-HLA-DR-CD38 molecules increased in the CD4+ T cells of HI patients/no-cART who also showed a lower frequency of CD127+CD28+ CD4+ T cells than HI patients/cART and HU group subjects. There were significant negative correlations between the frequency of exhausted CD4+ T cells and the SBA response. IL-4 levels were higher in HI patients/cART and positively correlated with SBA titers but negatively associated with the expression of exhaustion markers. Moreover, the CXCL-13 levels were positively correlated with the exhausted CD4+ T cells.

CONCLUSION

The results of our study suggest that the co-expression of exhaustion markers and/or loss of co-stimulatory molecules influence the SBA response in HI patients.

Viral infections and implications for male reproductive health

Viral infections have haunted humankind since times immemorial. Overpopulation, globalization, and extensive deforestation have created an ideal environment for a viral spread with unknown and multiple shedding routes. Many viruses can infect the male reproductive tract, with potential adverse consequences to male reproductive health, including infertility and cancer. Moreover, some genital tract viral infections can be sexually transmitted, potentially impacting the resulting offspring's health. We have summarized the evidence concerning the presence and adverse effects of the relevant viruses on the reproductive tract (mumps virus, human immunodeficiency virus, herpes virus, human papillomavirus, hepatitis B and C viruses, Ebola virus, Zika virus, influenza virus, and coronaviruses), their routes of infection, target organs and cells, prevalence and pattern of virus shedding in semen, as well as diagnosis/testing and treatment strategies. The pathophysiological understanding in the male genital tract is essential to assess its clinical impact on male reproductive health and guide future research.

Consumptive coagulopathy of severe yellow fever occurs independently of hepatocellular tropism and massive hepatic injury

Yellow fever (YF) is a mosquito-transmitted viral disease that causes tens of thousands of deaths each year despite the long-standing deployment of an effective vaccine. In its most severe form, YF manifests as a hemorrhagic fever that causes severe damage to visceral organs. Although coagulopathy is a defining feature of severe YF in humans, the mechanism by which it develops remains uncertain. Hepatocytes are a major target of yellow fever virus (YFV) infection, and the coagulopathy in severe YF has long been attributed to massive hepatocyte infection and destruction that results in a defect in clotting factor synthesis. However, when we analyzed blood from Brazilian patients with severe YF, we found high concentrations of plasma D-dimer, a fibrin split product, suggestive of a concurrent consumptive process. To define the relationship between coagulopathy and hepatocellular tropism, we compared infection and disease in Fah-/-, Rag2-/-, and Il2rɣ-/- mice engrafted with human hepatocytes (hFRG mice) and rhesus macaques using a highly pathogenic African YFV strain. YFV infection of macaques and hFRG mice caused substantial hepatocyte infection, liver damage, and coagulopathy as defined by virological, clinical, and pathological criteria. However, only macaques developed a consumptive coagulopathy whereas YFV-infected hFRG mice did not. Thus, infection of cell types other than hepatocytes likely contributes to the consumptive coagulopathy associated with severe YF in primates and humans. These findings expand our understanding of viral hemorrhagic disease and associated coagulopathy and suggest directions for clinical management of severe YF cases.

Factors associated with attitudes towards HIV cure research among transgender women and travestis: a cross-sectional survey in São Paulo, Brazil

OBJECTIVE

Characterising the perceptions of groups most affected by HIV is fundamental in establishing guidelines for biomedical advancement. Although Brazil has successfully fought HIV/AIDS through several measures, transgender women still have a likelihood of HIV infection 55 times higher than the general population. This study aimed to better understand the perception and awareness of HIV cure research among the trans-identifying population in São Paulo, Brazil, and to determine factors that motivate or discourage participation in HIV cure studies.

SETTING

This cross-sectional study analysed data collected from a questionnaire administered to 118 transgender women and travestis at 5 sites within the city of São Paulo. It uses quantitative methodology to describe the perspectives of transgender and travesti people in relation to HIV cure research and the context in which such perspectives are produced.

RESULTS

Of 118 participants, most participants (73%) had some knowledge of HIV cure research and were most willing to participate in online surveys (52%), interviews (52%), focus groups (52%) and studies involving blood draws (57%). Those with a higher education or employment status were more likely to agree that someone had been cured of HIV, people living with HIV are discriminated against, and more information about HIV cure research is needed before the community embraces it. Only 55% of participants completely trusted their physician. The biggest motivational factors included gaining additional knowledge about HIV infection (77%) and the potential for a longer, healthier life for all (73%).

CONCLUSIONS

As a primary analysis of HIV cure attitudes among the transgender and travesti population as well as the social context in which they are formed, this study identifies opportunities to strengthen the dialogue and develop more educational collaborations between scientific investigators, community educators and the trans-identifying population to ensure that HIV cure research is inclusive of diverse perspectives.

Double-Blind, Randomized, Placebo-Controlled Phase III Clinical Trial to Evaluate the Efficacy and Safety of treating Healthcare Professionals with the Adsorbed COVID-19 (Inactivated) Vaccine Manufactured by Sinovac - PROFISCOV: A structured summary of a study protocol for a randomised controlled trial

Objectives

To evaluate the efficacy of two doses of the adsorbed vaccine COVID-19 (inactivated) produced by Sinovac in symptomatic individuals, with virological confirmation of COVID-19, two weeks after the completion of the two-dose vaccination regimen, aged 18 years or older who work as health professionals providing care to patients with possible or confirmed COVID-19.

To describe the occurrence of adverse reactions associated with the administration of each of two doses of the adsorbed vaccine COVID-19 (inactivated) produced by Sinovac up to one week after vaccination in Adults (18-59 years of age) and Elderly (60 years of age or more).

Trial design

This is a Phase III, randomized, multicenter, endpoint driven, double-blind, placebo-controlled clinical trial to assess the efficacy and safety of the adsorbed vaccine COVID-19 (inactivated) produced by Sinovac.

The adsorbed vaccine COVID-19 (inactivated) produced by Sinovac (product under investigation) will be compared to placebo. Voluntary participants will be randomized to receive two intramuscular doses of the investigational product or the placebo, in a 1: 1 ratio, stratified by age group (18 to 59 years and 60 years or more) and will be monitored for one year by active surveillance of COVID-19. Two databases will be established according to the age groups: one for adults (18-59 years) and one for the elderly (60 years of age or older).

The threshold to consider the vaccine efficacious will be to reach a protection level of at least 50%, as proposed by the World Health Organization and the FDA. Success in this criterion will be defined by sequential monitoring with adjustment of the lower limit of the 95% confidence interval above 30% for the primary efficacy endpoint.

Participants

Healthy participants and / or participants with clinically controlled disease, of both genders, 18 years of age or older, working as health professionals performing care in units specialized in direct contact with people with possible or confirmed cases of COVID-19. Participation of pregnant women and those who are breastfeeding, as well as those intending to become pregnant within three months after vaccination will not be allowed. Participants will only be included after signing the voluntary Informed Consent Form and ensuring they undergo screening evaluation and conform to all the inclusion and exclusion criteria. All the clinical sites are located in Brazil.

Intervention and comparator

Experimental intervention: The vaccine was manufactured by Sinovac Life Sciences (Beijing, China) and contains 3 μg/0.5 mL (equivalent to 600 SU per dose) of inactivated SARS-CoV-2 virus, and aluminium hydroxide as adjuvant.

Control comparator: The placebo contains aluminium hydroxide in a 0.5 mL solution

The schedule of both, experimental intervention and placebo is two 0.5 mL doses IM (deltoid) with a two week interval.

Main outcomes

The primary efficacy endpoint is the incidence of symptomatic cases of virologically confirmed COVID-19 two weeks after the second vaccination. The virological diagnosis will be confirmed by detection of SARS-CoV-2 nucleic acid in a clinical sample.

The primary safety endpoint is the frequency of solicited and unsolicited local and systemic adverse reactions during the period of one week after vaccination according to age group in adult (18-59 years old) and elder (60 years of age or older) subjects. Adverse reactions are defined as adverse events that have a reasonable causal relationship to vaccination.

Randomisation

There will be two randomization lists, one for each age group, based on the investigational products to be administered, i.e., vaccine or placebo at a 1: 1 ratio. Each randomization list will be made to include up to 11,800 (18-59 year-old) adults, and 1,260 elderly (60 y-o and older) participants, the maximum number of participants needed per age group. An electronic central randomization system will be used to designate the investigational product that each participant must receive.

Blinding (masking)

This trial is designed as a double-blind study to avoid introducing bias in the evaluation of efficacy, safety and immunogenicity. The clinical care team, the professionals responsible for the vaccination and the participants will not know which investigational product will be administered. Only pharmacists or nurses in the study who are responsible for the randomization, separation and blinding of the investigational product will have access to unblinded information. The sponsor's operational team will also remain blind.

Numbers to be randomised (sample size)

The total number of participants needed to evaluate efficacy, 13,060 participants, satisfies the needed sample size calculated to evaluate safety. Therefore, the total number obtained for efficacy will be the number retained for the study. Up to 13,060 participants are expected to enter the study, with up to 11,800 participants aged 18 to 59 years and 1,260 elderly participants aged 60 and over. Half of the participants of each group will receive the experimental vaccine and half of them will receive the placebo. The recruitment of participants may be modified as recommended by the Data Safety Monitoring Committee at time of the interim unblinded analysis or blind assessment of the COVID-19 attack rate during the study.

Trial Status

Protocol version 2.0 – 24-Aug-2020. Recruitment started on July 21^st, 2020. The recruitment is expected to conclude in October 2020.

Trial registration

ClinicalTrials.gov Identifier: NCT0445659. Registry on 2 July 2020

Full protocol

The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest in expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol.

Antigenic competition in CD4+ T cell responses in a randomized, multicenter, double-blind clinical HIV vaccine trial

T cell responses have been implicated in reduced risk of HIV acquisition in uninfected persons and control of viral replication in HIV-infected individuals. HIV Gag-specific T cells have been predominantly associated with post-infection control, whereas Env antigens are the target for protective antibodies; therefore, inclusion of both antigens is common in HIV vaccine design. However, inclusion of multiple antigens may provoke antigenic competition, reducing the potential effectiveness of the vaccine. HVTN 084 was a randomized, multicenter, double-blind phase 1 trial to investigate whether adding Env to a Gag/Pol vaccine decreases the magnitude or breadth of Gag/Pol-specific T cell responses. Fifty volunteers each received one intramuscular injection of 1 × 10¹⁰ particle units (PU) of rAd5 Gag/Pol and EnvA/B/C (3:1:1:1 mixture) or 5 × 10⁹ PU of rAd5 Gag/Pol. CD4⁺ T cell responses to Gag/Pol measured 4 weeks after vaccination by cytokine expression were significantly higher in the group vaccinated without Env, whereas CD8⁺ T cell responses did not differ significantly between the two groups. Mapping of individual epitopes revealed greater breadth of the Gag/Pol-specific T cell response in the absence of Env compared to Env coimmunization. Addition of an Env component to a Gag/Pol vaccine led to reduced Gag/Pol CD4⁺ T cell response rate and magnitude as well as reduced epitope breadth, confirming the presence of antigenic competition. Therefore, T cell-based vaccine strategies should aim at choosing a minimalist set of antigens to reduce interference of individual vaccine components with the induction of the maximally achievable immune response.

Safety and immunogenicity of the tetravalent, live-attenuated dengue vaccine Butantan-DV in adults in Brazil: a two-step, double-blind, randomised placebo-controlled phase 2 trial

BACKGROUND

The Butantan Institute has manufactured a lyophilised tetravalent live-attenuated dengue vaccine Butantan-DV, which is analogous to the US National Institutes of Health (NIH) TV003 admixture. We aimed to assess the safety and immunogenicity of Butantan-DV.

METHODS

We did a two-step, double-blind, randomised placebo-controlled phase 2 trial at two clinical sites in São Paulo, Brazil. We recruited healthy volunteers aged 18-59 years; pregnant women, individuals with a history of neurological, heart, lung, liver or kidney disease, diabetes, cancer, or autoimmune diseases, and individuals with HIV or hepatitis C were excluded. Step A was designed as a small bridge-study between Butantan-DV and TV003 in DENV-naive participants. In step A, we planned to randomly assign 50 dengue virus (DENV)-naive individuals to receive two doses of Butantan-DV, TV003, or placebo, given 6 months apart. In step B, we planned to randomly assign 250 participants (DENV-naive and DENV-exposed) to receive one dose of Butantan-DV or placebo. Participants were randomly assigned, by computer-generated block randomisation (block sizes of five); participants in step A were randomly assigned (2:2:1) to receive Butantan-DV, TV003, or placebo and participants in step B were randomly assigned (4:1) to receive Butantan-DV or placebo. Participants and study staff were unaware of treatment allocation. The primary safety outcome was the frequency of solicited and unsolicited local and systemic adverse reactions within 21 days of the first vaccination, analysed by intention to treat. The primary immunogenicity outcome was seroconversion rates of the DENV-1-4 serotypes measured 91 days after the first vaccination, analysed in the per-protocol population, which included all participants in step A, and all participants included in step B who completed all study visits with serology sample collection. This trial is registered with ClinicalTrials.gov, NCT01696422.

FINDINGS

Between Nov 5, 2013, and Sept 21, 2015, 300 individuals were enrolled and randomly assigned: 155 (52%) DENV-naive participants and 145 (48%) DENV-exposed participants. Of the 155 DENV-naive participants, 97 (63%) received Butantan-DV, 17 (11%) received TV003, and 41 (27%) received placebo. Of the 145 DENV-exposed participants, 113 (78%) received Butantan-DV, three (2%) received TV003, and 29 (20%) received placebo. Butantan-DV and TV003 were both immunogenic, well-tolerated, and no serious adverse reactions were observed. In step A, rash was the most frequent adverse event (16 [845] of 19 participants in the Butantan-DV group and 13 [76%] of 17 participants in the TV003 group). Viraemia was similar between the Butantan-DV and TV003 groups. Of the 85 DENV-naive participants in the Butantan-DV group who attended all visits for sample collection for seroconversion analysis and thus were included in the per-protocol analysis population, 74 (87%) achieved seroconversion to DENV-1, 78 (92%) to DENV-2, 65 (76%) to DENV-3, and 76 (89%) to DENV-4. Of the 101 DENV-exposed participants in the Butantan-DV group who attended all visits for sample collection for seroconversion analysis, 82 (81%) achieved seroconversion to DENV-1, 79 (78%) to DENV-2, 83 (82%) to DENV-3, and 78 (77%) to DENV-4.

INTERPRETATION

Butantan-DV and TV003 were safe and induced robust, balanced neutralising antibody responses against the four DENV serotypes. Efficacy evaluation of the Butantan-DV vaccine is ongoing.

FUNDING

Intramural Research Program US NIH National Institute of Allergy and Infectious Diseases, Brazilian National Bank for Economic and Social Development, Fundação de Amparo à Pesquisa do Estado de São Paulo, and Fundação Butantan.

Characterization of a novel dengue virus strain and its implication for vaccine development

Dengue virus (DENV) causes up to 390 million infections yearly worldwide. Currently, four serotypes, DENV 1–4, circulate between Aedes mosquitoes and humans and can cause severe dengue, which has been associated with secondary DENV infection by a different serotype. DENV strain DKE-121 was recently isolated from Malaysia and is 12–38% different in its envelope protein from DENV 1–4. While previous studies of DENV genetic variation have described up to 3% amino acid divergence within a serotype, this virus differs by up to 12% from DENV4, suggesting its possible classification as a new serotype. The potential of a new DENV serotype emerging into circulation raises concerns of increased risk of severe dengue and uncertainty of how protective current tetravalent vaccine efforts would be. We tested the ability of serum from mice, non-human primates (NHPs), and humans that were infected or vaccinated with DENV4 and DKE-121 to neutralize infection of DENV4 and DKE-121. NHPs and humans immunized with DENV4 had 2 and 5-fold higher neutralizing titers (EC50 values), respectively, against the homologous DENV4 than DKE-121. However, mice boosted with DENV4 had similar neutralizing titers against DENV4 and DKE-121. In comparison, DKE-121 infection in NHPs and mice elicited 3-fold and up to 21-fold, respectively, higher titers against DKE-121 than DENV4. In addition, DKE-121 was poorly neutralized by type-specific anti-DENV4 monoclonal antibodies (mAbs), and reciprocally neutralizing mAbs against DKE-121 did not inhibit DENV4 infection. Using polyclonal sera and mAbs, DKE-121 and DENV4 show substantive differences in antigenicity. Ongoing studies are aimed at determining how these differences affect antibody-mediated protection in vivo.

The Vaginal Microbiome as a Tool to Predict rASRM Stage of Disease in Endometriosis: a Pilot Study

Endometriosis remains a challenge to understand and to diagnose. This is an observational cross-sectional pilot study to characterize the gut and vaginal microbiome profiles among endometriosis patients and control subjects without the disease and to explore their potential use as a less-invasive diagnostic tool for endometriosis. Overall, 59 women were included, n = 35 with endometriosis and n = 24 controls. Rectal and vaginal samples were collected in two different periods of the menstrual cycle from all subjects. Gut and vaginal microbiomes from patients with different rASRM (revised American Society for Reproductive Medicine) endometriosis stages and controls were analyzed. Illumina sequencing libraries were constructed using a two-step 16S rRNA gene PCR amplicon approach. Correlations of 16S rRNA gene amplicon data with clinical metadata were conducted using a random forest-based machine-learning classification analysis. Distribution of vaginal CSTs (community state types) significantly differed between follicular and menstrual phases of the menstrual cycle (p = 0.021, Fisher's exact test). Vaginal and rectal microbiome profiles and their association to severity of endometriosis (according to rASRM stages) were evaluated. Classification models built with machine-learning methods on the microbiota composition during follicular and menstrual phases of the cycle were built, and it was possible to accurately predict rASRM stages 1-2 verses rASRM stages 3-4 endometriosis. The feature contributing the most to this prediction was an OTU (operational taxonomic unit) from the genus Anaerococcus. Gut and vaginal microbiomes of women with endometriosis have been investigated. Our findings suggest for the first time that vaginal microbiome may predict stage of disease when endometriosis is present.

HIV-1 genetic diversity and divergence and its correlation with disease progression among antiretroviral naïve recently infected individuals

HIV-1 genetic diversity evolution was deeply characterized during the first year of infection among recently-infected patients using deep sequencing technology and correlated with disease progression surrogate markers. RNA and DNA samples from twenty-five individuals (13 female) encoding the protease and reverse transcriptase regions of the pol gene, and the V3 region of the env gene were evaluated at recent infection and during established infection. Infection by a unique HIV-1 strain was inferred in 70.1% of the individuals, with no differences between genders. Infections by multiple strains were associated with higher viral loads and faster CD4⁺ T cell declines. Either low or high levels of viral loads accompanied low levels of genetic diversity and lower selective pressure. With massive sequence data from 3 distinct genomic HIV-1 regions from plasma and PBMCs over time, we propose a model for HIV-1 genetic diversity, which correlates to basal viral loads of patients.

Generation of Zika virus-specific T cells from seropositive and virus-naïve donors for potential use as an autologous or "off-the-shelf" immunotherapeutic

BACKGROUND

Zika virus (ZIKV) infection can cause severe birth defects in newborns with no effective currently available treatment. Adoptive transfer of virus-specific T cells has proven to be safe and effective for the prevention or treatment of many viral infections, and could represent a novel treatment approach for patients with ZIKV infection. However, extending this strategy to the ZIKV setting has been hampered by limited data on immunogenic T-cell antigens within ZIKV. Hence, we have generated ZIKV-specific T cells and characterized the cellular immune responses against ZIKV antigens.

METHODS

T-cell products were generated from peripheral blood of ZIKV-exposed donors, ZIKV-naive adult donors and umbilical cord blood by stimulation with pentadecamer (15mer) overlapping peptide libraries spanning four ZIKV polyproteins (C, M, E and NS1) using a Good Manufacturing Practice-compliant protocol.

RESULTS

We successfully generated T cells targeting ZIKV antigens with clinically relevant numbers. The ex vivo-expanded T cells comprised both CD4⁺ and CD8⁺ T cells that were able to produce Th1-polarized effector cytokines and kill ZIKV-infected HLA-matched monocytes, confirming functionality of this unique T-cell product as a potential "off-the-shelf" therapeutic. Epitope mapping using peptide arrays identified several novel HLA class I and class II-restricted epitopes within NS1 antigen, which is essential for viral replication and immune evasion.

DISCUSSION

Our findings demonstrate that it is feasible to generate potent ZIKV-specific T cells from a variety of cell sources including virus naïve donors for future clinical use in an "off-the-shelf" setting.

Predictors of mortality in patients with yellow fever: an observational cohort study

BACKGROUND

Yellow fever virus infection results in death in around 30% of symptomatic individuals. The aim of this study was to identify predictors of death measured at hospital admission in a cohort of patients admitted to hospital during the 2018 outbreak of yellow fever in the outskirts of São Paulo city, Brazil.

METHODS

In this observational cohort study, we enrolled patients with yellow fever virus from two hospitals in São Paolo-the Hospital das Clínicas, University of São Paulo and the Infectious Diseases Institute "Emilio Ribas". Patients older than 18 years admitted to hospital with fever or myalgia, headache, arthralgia, oedema, rash, or conjunctivitis were consecutively screened for inclusion in the present study. Consenting patients were included if they had travelled to geographical areas in which yellow fever virus cases had been previously confirmed. Yellow fever infection was confirmed by real-time PCR in blood collected at admission or tissues at autopsy. We sequenced the complete genomes of yellow fever virus from infected individuals and evaluated demographic, clinical, and laboratory findings at admission and investigated whether any of these measurements correlated with patient outcome (death).

FINDINGS

Between Jan 11, 2018, and May 10, 2018, 118 patients with suspected yellow fever were admitted to Hospital das Clínicas, and 113 patients with suspected yellow fever were admitted to Infectious Diseases Institute "Emilio Ribas". 95 patients with suspected yellow fever were included in the study, and 136 patients were excluded. Three (3%) of 95 patients with suspected yellow fever who were included in the study were excluded because they received a different diagnosis, and 16 patients with undetectable yellow fever virus RNA were excluded. Therefore, 76 patients with confirmed yellow fever virus infection, based on detectable yellow fever virus RNA in blood (74 patients) or yellow fever virus confirmed only at the autopsy report (two patients), were included in our analysis. 27 (36%) of 76 patients died during the 60 day period after hospital admission. We generated 14 complete yellow fever virus genomes from the first 15 viral load-detectable samples. The genomes belonged to a single monophyletic clade of the South America I genotype, sub-genotype E. Older age, male sex, higher leukocyte and neutrophil counts, higher alanine aminotransferase, aspartate transaminase (AST), bilirubin, and creatinine, prolonged prothrombin time, and higher yellow fever virus RNA plasma viral load were associated with higher mortality. In a multivariate regression model, older age, elevated neutrophil count, increased AST, and higher viral load remained independently associated with death. All 11 (100%) patients with neutrophil counts of 4000 cells per mL or greater and viral loads of 5·1 log₁₀ copies/mL or greater died (95% CI 72-100), compared with only three (11%) of 27 (95% CI 2-29) among patients with neutrophil counts of less than 4000 cells per mL and viral loads of less than 5·1 log₁₀ copies/mL.

INTERPRETATION

We identified clinical and laboratory predictors of mortality at hospital admission that could aid in the care of patients with yellow fever virus. Identification of these prognostic markers in patients could help clinicians prioritise admission to the intensive care unit, as patients often deteriorate rapidly. Moreover, resource allocation could be improved to prioritise key laboratory examinations that might be more useful in determining whether a patient could have a better outcome. Our findings support the important role of the virus in disease pathogenesis, suggesting that an effective antiviral could alter the clinical course for patients with the most severe forms of yellow fever.

FUNDING

São Paulo Research Foundation (FAPESP).

Short Communication: Dried Blood Spots Stored at Room Temperature Should Not Be Used for HIV Incidence Testing

The limiting antigen (LAg)-avidity assay is a serologic assay used for cross-sectional HIV incidence testing. We compared the results obtained with the LAg-avidity assay using dried blood spot (DBS) samples stored at room temperature (18°C-25°C) or stored frozen at -80°C with results obtained from matched plasma samples. Matched DBS and plasma samples (306 paired samples) were collected in the HIV Prevention Trials Network (HPTN) 068 trial in South Africa (2012-2014). The DBS were stored at room temperature before testing. Matched DBS and plasma samples (100 paired samples) from the Consortium for the Evaluation and Performance of HIV Incidence Assays (CEPHIA) were collected in 2016 and were stored at -80°C. All DBS testing was performed in 2017. Differences in normalized optical density (ODn) were compared between matched DBS and plasma samples. For DBS samples stored at room temperature (HPTN 068), the average difference in ODn values for plasma versus DBS was 1.49 (95% confidence intervals [CI]: 1.36-1.62). In contrast, when DBS samples were stored at -80°C (CEPHIA), the average difference in ODn values for plasma versus DBS was -0.22 (95% CI: -0.32 to -0.13). DBS samples stored at room temperature should not be used for cross-sectional HIV incidence testing with the LAg-avidity assay.

HLA-C downregulation by HIV-1 adapts to host HLA genotype

HIV-1 can downregulate HLA-C on infected cells, using the viral protein Vpu, and the magnitude of this downregulation varies widely between primary HIV-1 variants. The selection pressures that result in viral downregulation of HLA-C in some individuals, but preservation of surface HLA-C in others are not clear. To better understand viral immune evasion targeting HLA-C, we have characterized HLA-C downregulation by a range of primary HIV-1 viruses. 128 replication competent viral isolates from 19 individuals with effective anti-retroviral therapy, show that a substantial minority of individuals harbor latent reservoir virus which strongly downregulates HLA-C. Untreated infections display no change in HLA-C downregulation during the first 6 months of infection, but variation between viral quasispecies can be detected in chronic infection. Vpu molecules cloned from plasma of 195 treatment naïve individuals in chronic infection demonstrate that downregulation of HLA-C adapts to host HLA genotype. HLA-C alleles differ in the pressure they exert for downregulation, and individuals with higher levels of HLA-C expression favor greater viral downregulation of HLA-C. Studies of primary and mutant molecules identify 5 residues in the transmembrane region of Vpu, and 4 residues in the transmembrane domain of HLA-C, which determine interactions between Vpu and HLA. The observed adaptation of Vpu-mediated downregulation to host genotype indicates that HLA-C alleles differ in likelihood of mediating a CTL response that is subverted by viral downregulation, and that preservation of HLA-C expression is favored in the absence of these responses. Finding that latent reservoir viruses can downregulate HLA-C could have implications for HIV-1 cure therapy approaches in some individuals.