SARS-CoV-2 B.1.617.2 Delta variant replication and immune evasion

Abstract: The B.1.617.2 (Delta) variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first identified in the state of Maharashtra in late 2020 and spread throughout India, outcompeting pre-existing lineages including B.1.617.1 (Kappa) and B.1.1.7 (Alpha)1. In vitro, B.1.617.2 is sixfold less sensitive to serum neutralizing antibodies from recovered individuals, and eightfold less sensitive to vaccine-elicited antibodies, compared with wild-type Wuhan-1 bearing D614G. Serum neutralizing titres against B.1.617.2 were lower in ChAdOx1 vaccinees than in BNT162b2 vaccinees. B.1.617.2 spike pseudotyped viruses exhibited compromised sensitivity to monoclonal antibodies to the receptor-binding domain and the amino-terminal domain. B.1.617.2 demonstrated higher replication efficiency than B.1.1.7 in both airway organoid and human airway epithelial systems, associated with B.1.617.2 spike being in a predominantly cleaved state compared with B.1.1.7 spike. The B.1.617.2 spike protein was able to mediate highly efficient syncytium formation that was less sensitive to inhibition by neutralizing antibody, compared with that of wild-type spike. We also observed that B.1.617.2 had higher replication and spike-mediated entry than B.1.617.1, potentially explaining the B.1.617.2 dominance. In an analysis of more than 130 SARS-CoV-2-infected health care workers across three centres in India during a period of mixed lineage circulation, we observed reduced ChAdOx1 vaccine effectiveness against B.1.617.2 relative to non-B.1.617.2, with the caveat of possible residual confounding. Compromised vaccine efficacy against the highly fit and immune-evasive B.1.617.2 Delta variant warrants continued infection control measures in the post-vaccination era

Need for revisiting the role of sexually transmitted disease clinics in government hospitals in India

Introduction: The Government of India provides treatment for sexually transmitted infections (STIs) through government's sexually transmitted disease (STD) clinics with the mandate of providing curative and preventive services for clients in the context of STIs. However, besides the patients suffering from STDs, other clients with problems related to reproductive and sexual health also attend these clinics. This study aimed to assess the profile and treatment-seeking behavior of clients attending STD clinics in government hospitals in India. Materials and Methods: This multicentric, cross-sectional study with 5098 participants was conducted over 2 months in identified 19 Indian states. Chi–square test was used for statistical analysis. Results: The percentage with STDs (62.98%) was nearly double than those with non-STDs (37.1%). Around 8.2% of patients had an STD and were also HIV positive. Compared to the total STD cases, only 9% of the partners had turned up for screening. Of significance were the non-STD cases who presented with both physical and psychological symptoms including infertility. Among males, it was mainly sexual dysfunction and balanoposthitis, and in females, lower abdominal pain and bacterial vaginosis. Only 27.3% reported that they had come directly to the government facility/clinic. Nearly 38% of males and 30% of females had tried home remedies before coming to the government clinic. Majority (77.9%) of the clients reported that they had never been counseled on any aspect of STD or HIV. Conclusion: The profile of clients in the various clinics across the country indicates that the name “STD Clinic” is a misnomer since the presenting complaints of clients are varied, and related not only to STDs but also to other reproductive tract problems. Furthermore, the average new patient load observed in our study is low and this was attributed to the name “STDs” given to these clinics. Renaming them as “Reproductive Health Clinics” would attract more patients and lead to better utilization

Transmission of B.1.617.2 Delta variant between vaccinated healthcare workers

AbstractBreakthrough infections with SARS-CoV-2 Delta variant have been reported in doubly-vaccinated recipients and as re-infections. Studies of viral spread within hospital settings have highlighted the potential for transmission between doubly-vaccinated patients and health care workers and have highlighted the benefits of high-grade respiratory protection for health care workers. However the extent to which vaccination is preventative of viral spread in health care settings is less well studied. Here, we analysed data from 118 vaccinated health care workers (HCW) across two hospitals in India, constructing two probable transmission networks involving six HCWs in Hospital A and eight HCWs in Hospital B from epidemiological and virus genome sequence data, using a suite of computational approaches. A maximum likelihood reconstruction of transmission involving known cases of infection suggests a high probability that doubly vaccinated HCWs transmitted SARS-CoV-2 between each other and highlights potential cases of virus transmission between individuals who had received two doses of vaccine. Our findings show firstly that vaccination may reduce rates of transmission, supporting the need for ongoing infection control measures even in highly vaccinated populations, and secondly we have described a novel approach to identifying transmissions that is scalable and rapid, without the need for an infection control infrastructure.</jats:p