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Background BBV152 is a whole-virion inactivated SARS-CoV-2 vaccine (3 µg or 6 µg) formulated with a toll-like receptor 7/8 agonist molecule (IMDG) adsorbed to alum (Algel). We previously reported findings from a doubleblind, multicentre, randomised, controlled phase 1 trial on the safety and immunogenicity of three different formulations of BBV152 (3 μg with Algel-IMDG, 6 μg with Algel-IMDG, or 6 μg with Algel) and one Algel-only control (no antigen), with the first dose administered on day 0 and the second dose on day 14. The 3 µg and 6 µg with Algel-IMDG formulations were selected for this phase 2 study. Herein, we report interim findings of the phase 2 trial on the immunogenicity and safety of BBV152, with the first dose administered on day 0 and the second dose on day 28.Methods We did a double-blind, randomised, multicentre, phase 2 clinical trial to evaluate the immunogenicity and safety of BBV152 in healthy adults and adolescents (aged 12-65 years) at nine hospitals in India. Participants with positive SARS-CoV-2 nucleic acid and serology tests were excluded. Participants were randomly assigned (1:1) to receive either 3 µg with Algel-IMDG or 6 µg with Algel-IMDG. Block randomisation was done by use of an interactive web response system. Participants, investigators, study coordinators, study-related personnel, and the sponsor were masked to treatment group allocation. Two intramuscular doses of vaccine were administered on day 0 and day 28. The primary outcome was SARS-CoV-2 wild-type neutralising antibody titres and seroconversion rates (defined as a post-vaccination titre that was at least four-fold higher than the baseline titre) at 4 weeks after the second dose (day 56), measured by use of the plaque-reduction neutralisation test (PRNT 50 ) and the microneutralisation test (MNT 50 ). The primary outcome was assessed in all participants who had received both doses of the vaccine. Cell-mediated responses were a secondary outcome and were assessed by T-helper-1 (Th1)/Th2 profiling at 2 weeks after the second dose (day 42). Safety was assessed in all participants who received at least one dose of the vaccine. In addition, we report immunogenicity results from a follow-up blood draw collected from phase 1 trial participants at 3 months after they received the second dose (day 104). This trial is registered at ClinicalTrials.gov, NCT04471519. FindingsBetween Sept 5 and 12, 2020, 921 participants were screened, of whom 380 were enrolled and randomly assigned to the 3 µg with Algel-IMDG group (n=190) or 6 µg with Algel-IMDG group (n=190). Geometric mean titres (GMTs; PRNT 50 ) at day 56 were significantly higher in the 6 µg with Algel-IMDG group (197•0 [95% CI 155•6-249•4]) than the 3 µg with Algel-IMDG group (100•9 [74•1-137•4]; p=0•0041). Seroconversion based on PRNT 50 at day 56 was reported in 171 (92•9% [95% CI 88•2-96•2] of 184 participants in the 3 µg with Algel-IMDG group and 174 (98•3% [95•1-99•6]) of 177 participants in the 6 µg with Algel-IMDG group. GMTs (MNT 50 ) at day 56 were 92•5 (95% CI 77•7-11...

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Learning to imitate expert behavior from demonstrations can be challenging, especially in environments with high-dimensional, continuous observations and unknown dynamics. Supervised learning methods based on behavioral cloning (BC) suffer from distribution shift: because the agent greedily imitates demonstrated actions, it can drift away from demonstrated states due to error accumulation. Recent methods based on reinforcement learning (RL), such as inverse RL and generative adversarial imitation learning (GAIL), overcome this issue by training an RL agent to match the demonstrations over a long horizon. Since the true reward function for the task is unknown, these methods learn a reward function from the demonstrations, often using complex and brittle approximation techniques that involve adversarial training. We propose a simple alternative that still uses RL, but does not require learning a reward function. The key idea is to provide the agent with an incentive to match the demonstrations over a long horizon, by encouraging it to return to demonstrated states upon encountering new, out-of-distribution states. We accomplish this by giving the agent a constant reward of r = +1 for matching the demonstrated action in a demonstrated state, and a constant reward of r = 0 for all other behavior. Our method, which we call soft Q imitation learning (SQIL), can be implemented with a handful of minor modifications to any standard Q-learning or off-policy actor-critic algorithm. Theoretically, we show that SQIL can be interpreted as a regularized variant of BC that uses a sparsity prior to encourage long-horizon imitation. Empirically, we show that SQIL outperforms BC and achieves competitive results compared to GAIL, on a variety of image-based and low-dimensional tasks in Box2D, Atari, and MuJoCo. This paper is a proof of concept that illustrates how a simple imitation method based on RL with constant rewards can be as effective as more complex methods that use learned rewards.Preprint. Under review.

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BackgroundThe stillbirth rate is an indicator of quality of care during pregnancy and delivery. Good quality care is supported by a functional heath system. The objective of this study was to explore the risk factors for stillbirths, particularly those related to a health system.MethodsThis case-control study was conducted in two districts of Bihar, India. Information on cases (stillbirths) were obtained from facilities as reported by Health Management Information System; controls were consecutive live births from the same population as cases. Data were collected from 400 cases and 800 controls. The risk factors were compared using a hierarchical approach and expressed as odds ratio, attributable fractions and population attributable fractions.ResultsOf all the factors studied, 22 risk factors were independently associated with stillbirths. Health system-related factors were: administration of two or more doses of oxytocics to augment labour before reaching the facilities (OR 1.6; 95% CI 1.2–2.1), any complications during labour (OR 2.3;1.7–3.1), >30 min to reach a facility from home (OR 1.4;1.05–1.8), >10 min to attend to the pregnant woman after reaching the facility (OR 2.8;1.7–4.5). In the final regression model, modifiable health system-related risk factors included: >10 min taken to attend to women after they reach the facilities (AOR 3.6; 95% CI 2.5–5.1), untreated hypertension during pregnancy (AOR 2.9; 95% CI 1.5–5.6) and presence of any complication during labour, warranting treatment (AOR 1.7; 95% CI 1.2–2.4). Among mothers who reported complications during labour, time taken to reach the facility was significantly different between stillbirths and live births (2nd delay; 33.5 min v/s 25 min; p < 0.001). Attributable fraction for any complication during labour was 0.56 (95% CI 0.42–0.67), >30 min to reach the facility 0.48 (95% CI 0.31–0.60) and institution of management 10 min after reaching the facility 0.68 (95% CI 0.58–0.75). Reaching a facility within 30 min, initiation of management within 10 min of reaching the facility and timely management of complications during labour could have prevented 17%, 37% and 20% of stillbirths respectively.ConclusionA pro-active health system with accessible, timely and quality obstetric services can prevent a considerable proportion of stillbirths in low and middle income countries.Electronic supplementary materialThe online version of this article (10.1186/s12884-018-1660-1) contains supplementary material, which is available to authorized users.

Background— Although various studies revealed the beneficial effects of statins in post–cardiac transplant patients, these were relatively small and low-powered studies. We performed a meta-analysis of published studies to evaluate the role of statins in post–cardiac transplant patients, specifically examining the effects on hemodynamically significant/fatal graft rejection, coronary vasculopathy, terminal cancer, and overall survival. Methods and Results— We searched PubMed, Cochran CENTRAL, and Web of Science databases using the search terms “cardiac transplant” or “heart transplant,” and “statin” for a literature search. A random-effects model with Mantel–Haenszel method was used to pool the data. We identified 10 studies, 4 randomized controlled trials, and 6 nonrandomized studies, which compared outcomes in heart transplant recipients undergoing statin therapy to statin-naive patients. A pooled analysis of 9 studies reporting mortality revealed that the use of statins was associated with significant reduction in all-cause mortality (odds ratio, 0.26; 95% confidence interval, 0.20–0.35; P <0.0001). Statins also decreased the odds of hemodynamically significant/fatal rejection (odds ratio, 0.37; 95% confidence interval, 0.21–0.65; P =0.0005), incidence of coronary vasculopathy (odds ratio, 0.33; 95% confidence interval, 0.16–0.68; P =0.003), and terminal cancer (odds ratio, 0.30; 95% confidence interval, 0.15–0.63; P =0.002). Conclusions— The evidence from a pooled analysis suggests that statins improve survival in heart transplant recipients. Statins may prevent fatal rejection episodes, decrease terminal cancer risk, and reduce the incidence of coronary vasculopathy. Additional prospective studies are needed to further investigate and explain this association.

BackgroundBBV152 is a whole-virion inactivated SARS-CoV-2 vaccine (3 µg or 6 µg) formulated with a Toll-like receptor 7/8 agonist molecule adsorbed to alum (Algel-IMDG). Earlier, we reported findings from a phase 1 (vaccination regimen on days 0 and 14) randomised, double-blind trial on the safety and immunogenicity of three different formulations of BBV152 and one control arm containing Algel (without antigen). Two formulations were selected for the phase 2 (days 0 and 28) study. Here, we report interim findings of a controlled, randomised, double-blind trial on the immunogenicity and safety of BBV152: 3 µg and 6 µg with Algel-IMDG.MethodsWe conducted a double-blind, randomised, multicentre, phase 2 clinical trial to evaluate the immunogenicity and safety of BBV152. A total of 380 healthy children and adults were randomised to receive two vaccine formulations (n=190 each) with 3 µg with Algel-IMDG and 6 µg with Algel-IMDG. Two intramuscular doses of vaccines were administered (four weeks apart). Participants, investigators, and laboratory staff were blinded to the treatment allocation. The primary outcome was seroconversion (≥4-fold above baseline) based on wild-type virus neutralisation (PRNT50). Secondary outcomes were reactogenicity and safety. Cell-mediated responses were evaluated. A follow-up blood draw was collected from phase 1 participants at day 104 (three months after the second dose).FindingsAmong 921 participants screened between Sep 7-13, 2020, 380 participants were randomised to the safety and immunogenicity population. The PRNT50 seroconversion rates of neutralising antibodies on day 56 were 92·9% (88·2, 96·2) and 98·3% (95·1, 99·6) in the 3 µg and 6 µg with Algel-IMDG groups, respectively. Higher neutralising titres (2-fold) were observed in the phase 2 study than in the phase 1 study (p<0.05). Both vaccine groups elicited more Th1 cytokines than Th2 cytokines. After two doses, the proportion (95% CI) of solicited local and systemic adverse reactions were 9.7% (6·9, 13·2) and 10.3% (7·4, 13·8) in the 3 µg and 6 µg with Algel-IMDG groups, respectively. No significant difference was observed between the groups. No serious adverse events were reported in this study. Phase 1 follow-up immunological samples at day 104 showed seroconversion in 73·5% (63·6, 81·9), 81·1% (71·4, 88·1), and 73·1% (62·9, 81·8) of individuals in the 3 µg with Algel-IMDG, 6 µg with Algel-IMDG, and 6 µg with Algel groups, respectively.InterpretationIn the phase 1 trial, BBV152 produced high levels of neutralising antibodies that remained elevated in all participants three months after the second vaccination. In the phase 2 trial, BBV152 led to tolerable safety outcomes and enhanced humoral and cell-mediated immune responses. The safety profile of BBV152 is noticeably lower than the rates for other SARS-CoV-2 vaccine platform candidates. The 6 µg Algel-IMDG formulation was selected for the phase 3 efficacy trial.FundingThis work was supported and funded by Bharat Biotech International Limited.Clinicaltrials.gov: NCT04471519