Effectiveness of Covid-19 vaccines (CovishieldTM and Covaxin ®) in healthcare workers in Mumbai, India: A retrospective cohort analysis.

BACKGROUND: India started its vaccination programme for Coronavirus-19 infection (COVID-19) on 16 January 2021 with CovishieldTM (Oxford/Astra Zeneca vaccine manufactured by Serum Institute of India) and Covaxin ® (Bharat Biotech, India). We designed the present study to study the effectiveness of vaccines for COVID-19 in prevention of breakthrough infections and severe symptomatic cases among health care workers in a real-life scenario in Mumbai, India. Furthermore, we also wanted to study the factors associated with this effectiveness. METHODS: This is cohort analysis of secondary data of 2762 individuals working in a tertiary health care setting in Mumbai, India (16 January 2021 to 16 October 2021). Vaccination records of all groups of health care staff (including the date of vaccination, type of vaccine taken, and date of positivity for COVID-19) were maintained at the hospital. The staff were tested for COVID-19 at least once a week and when symptomatic. The observation time for everyone was divided into unvaccinated, partially vaccinated (14 days after the first dose); and fully vaccinated (14 days after the second dose). If the individual was found to be positive, the day of positivity was considered the 'day of the event' for that individual. We combined unvaccinated/partially vaccinated into one group and completely vaccinated in the other group. We estimated hazard ratios (HR) and their 95% confidence intervals. The vaccine effectiveness (VE) was assessed as (1-HR)*100. RESULTS: The mean age (SD) of the study participants was 32.3 (8.3) years; majority of these individuals had taken Covishield TM (99.0%) and only 0.9% (n = 27) had taken Covaxin ®. The incidence rate in the overall population was 0.067/100 person-days (PD). The incidence rate was significantly higher in the unvaccinated/partially vaccinated group compared with the fully vaccinated group (0.0989 / 100 PD vs 0.0403/100 PD; p < 0.001). The adjusted HR (aHR) in the fully vaccinated group compared with the unvaccinated/partially vaccinated group in the complete cohort was 0.30 (95% CI: 0.23, 0.39). Thus, the vaccine effectiveness (VE) for full vaccination was 70% (95% CI: 61%, 77%). It remained the same in the Covishield TM only cohort. The VE in completely vaccinated and with a history of previous infection was 88% (95% CI: 80%, 93%). Only 11 health care workers required hospitalization over the entire observation period; the incidence rate in our cohort was 0.0016 / 100 PD. None of the HCWs reported any severe adverse events after vaccination. CONCLUSIONS: In this real-world scenario, we did find that complete vaccination reduced the rate of infection, particularly severe infection in health care personnel even during the severe delta wave in the country. Even among those infected, the hospitalisation rates were very low, and none died. We did not record any major side effects of vaccination in these personnel. Previous infection with COVID-19 and complete vaccination had a significantly higher effectiveness in prevention of infection.

Spectrum and prevalence of fungi infecting deep tissues of lower-limb wounds in patients with type 2 diabetes.

The prevalence rate and spectrum of fungi infecting deep tissues of diabetic lower-limb wounds (DLWs) have not been previously studied. Five hundred eighteen (382 male and 136 female) consecutive patients with type 2 diabetes hospitalized due to infected lower-limb wounds were enlisted in this study. Deep tissue (approximately 0.5- x 0.5-cm size) taken perioperatively from the wound bed was cultured for fungi. Fungi was found in 27.2% (141/518) of the study population. Candida parapsilosis (25.5%), Candida tropicalis (22.7%), Trichosporon asahii (12.8%), Candida albicans (10.6%), and Aspergillus species (5.0%) were the most predominant fungal isolates. Of the fungal isolates, 17.7% were resistant to itraconazole, 6.9% were resistant to amphotericin B, 6.9% were resistant to voriconazole, 3.9% were resistant to fluconazole, and 1.5% were resistant to flucytosine. Of the population, 79.7% (413/518) had bacterial infection in deep tissue. The predominant isolates were Enterococcus faecalis (14.1%), Staphylococcus aureus (12.2%), and Pseudomonas aeruginosa (10.8%). Mixed fungal and bacterial infections were seen in 21.4% of patients, while 5.8% had only fungal infection and 58.3% had only bacterial infections. Another 14.5% had neither bacteria nor fungi in the deep tissue. Patients with higher glycosylated hemoglobin levels had significantly more fungal infections. Our study reveals that deep-seated fungal infections are high in DLWs. In the context of delayed wound healing and amputation rates due to DLWs, it is important to study the pathogenicity of fungi in deep tissues of DLWs and their possible contribution to delayed wound healing. The role of antifungal agents in wound management needs to be evaluated further.