Dynamics of Antibody Response to Covishield Vaccine after 6 Months: A Longitudinal Prospective Study.

OBJECTIVES: To study the dynamics of antibody responses in the real world up to 6 months following two Covishield vaccination doses and evaluate its correlation with age. MATERIALS AND METHODS: From March 2021 to February 2022, a prospective, longitudinal study of healthcare workers (HCWs) from a dedicated COVID-19 hospital was conducted. Institutional Ethics Committee permission was obtained. HCWs were divided into two groups. The first group consisted of individuals who had received the first dose of the COVID-19 vaccine, with at least 3 weeks elapsed since the dose, and who had not received the second dose until the initial blood sample for antibody testing was obtained. The second group consisted of individuals who had received both COVID-19 doses and had at least 2 weeks between the administration of the second dose and the collection of the first sample for antibody testing. In March 2021, after undergoing phlebotomy for serum collection, the participants responded to the survey. Electrochemiluminescence immunoassay (ECLIA) was used to perform a quantitative test for antibodies to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike (S) protein receptor domain [receptor binding domain (RBD)]. The test used had a 98.8% sensitivity and a 99.9% specificity. If the antibody titer was 0.80 U/mL or higher, it was deemed positive; if it was lower, it was deemed negative. Two follow-ups were conducted for both groups, 3 and 6 months following the first sample collection. During both follow-up visits, a blood sample was obtained for testing the amount of antibody response, and the history of COVID-19 disease following the initial sample was taken. RESULTS: Every HCW had received the Covishield vaccination. After the vaccine's first dosage, 61 HCWs in the first group underwent antibody testing. The information about the 43 HCWs in the first group who attended the two follow-ups is as follows. There were 14 (32.6%) nurses and 5 (11.6%) doctors among the 43 HCWs. The age range was 21-55 years, with the median [interquartile range (IQR)] age being 26 (22-40) years and 20 (60.5%) being females. The vaccination series had a median (IQR) of 34 (29-49) days between doses. There was a statistically significant difference in immunoglobulin G (IgG) levels of the three samples, χ2 = 13.579, p = 0.001. Median (IQR) IgG levels of the three samples at 1 month after the first dose, 3 and 6 months after the second dose were 8511 (51-15400) U/mL, 1471 (249-5050) U/mL, and 978 (220-2854) U/mL, respectively. The antibody titer was negative for two HCWs in the first sample, positive in the rest of the samples, and positive in all samples in both follow-ups. In the second group, following two COVID-19 dosages, a total of 65 HCWs had tested positive for antibodies. The information of the 56 HCWs in group II who attended both follow-ups is as follows. Of the 56 HCWs, 15 (26.8%) were doctors, 27 (48.2%) were nurses, and 14 (25%) were others. The age range was 20-64 years, with a median (IQR) of 29.5 (22-37.7) and 31 (55.3%) female participants. The vaccination series had a median (IQR) interval of 32 (29-35) days between doses. There was a statistically significant difference in IgG levels of the three samples, χ2 = 31.107, p < 0.0001. Median (IQR) IgG levels of the three samples at 20 days, 3.8 months, and 7 months after the second dose were 2377.5, 1345.5, and 1257 U/mL, respectively. Spearman's rank order correlation was used to assess the association between IgG level and age in both groups. The relationship between IgG levels and age was weakly correlated and not statistically significant. CONCLUSION: There is a waning of antibody titer over time postimmunization. A lower antibody titer can be a contributing factor for infections that emerge later. IgG levels postvaccination do not differ according to age.

An observational study to find association between Hypertension and severe and fatal COVID-19 infection in COVID dedicated hospital, Mumbai.

Introduction: World Health Organization (WHO) has declared COVID-19 outbreak as a "public health emergency of international concern" on January 31, 2020. After that the epidemic spread rapidly around the world. Chronic non-communicable diseases were identified as risk factors for SARS-CoV-2. Hypertension (HTN) is one of the most common cardiovascular diseases with a prevalence ranging from 10% to 20% among adult population. After COVID-19 outbreak, identification of risk factors for severe or fatal disease is necessary to allocate limited resources. For primary care physicians, this is of vital importance to know the association between hypertension and severe and fatal COVID-19 infection as hypertension is affecting millions of people all over the world and primary health care is of immense importance in a country like India. Duration of stay in hospital which will be taken as proxy measure of duration of illness, symptomatic status, need of ICU care and death will be taken as indicators of severe and fatal COVID-19 infection. There are few researches to find an association between Hypertension and severe and fatal COVID-19 infection. There is a need to assess the same. Objectives: To find an association of hypertension and severe and fatal COVID-19 infection. Methodology: A hospital-based cross-sectional study was carried out at a COVID dedicated hospital, Mumbai in 9 months from 1 April 2020 to 31 December 2020. All patients admitted in hospital were included in the study by universal sampling. Ethical Approval: The permission to conduct the study was taken by Institutional Ethics Committee. Results: There was a significant association between hypertension and severe and fatal COVID-19 infection defined by more duration of stay in hospital, admission to ICU and mortality. Conclusions: It is concluded from this study that hypertension is associated with severe and fatal COVID-19 infection. It gives a clear idea for primary care physicians to give more focus towards patients with hypertension with COVID-19 infection. Blood pressure monitoring should be strictly practiced during COVID-like illnesses. Special attention is to be given as far as treatment and early referral to higher centre with ICU is concerned for better outcome. Hypertensive patients should be protected more by adopting COVID appropriate behaviour.

Epidemiological study to assess the impact of COVID-19 pandemic on the occurrence of monsoon-related diseases in the city of Mumbai.

BACKGROUND: The onset of monsoons in Mumbai poses an additional health disease burden in the form of rising vector-borne and water-borne diseases such as dengue, malaria, leptospirosis, hepatitis, typhoid, chikungunya, and acute gastroenteritis. These monsoon-related illnesses are preventable with hygienic and sanitation measures that are likely to have been adopted during COVID-19 pandemic. AIM: To assess the impact of COVID-19 pandemic on the occurrence of monsoon-related diseases in the city of Mumbai and find out determinants of variations if any. MATERIAL AND METHODS: This was a retrospective descriptive study. Universal sampling was done using secondary data collected from the Epidemiological Cell of Municipal Corporation of Greater Mumbai (MCGM). Data mining was performed to obtain the trends of the monsoon-related diseases in Mumbai. RESULTS: COVID-19 pandemic has remarkably affected the city of Mumbai with approximately 3 lakh cases till December 2020. MCGM has taken a lot of efforts resulting in a recovery rate of close to 95% with less than 3% mortality. With the effective use of social behavior change communication, which focused on masks, frequent hand washing, and social distancing, there seems to be a decline in monsoon-related illnesses in the year 2020 as compared to the previous two years of 2018 and 2019. CONCLUSION: Monsoon-related illnesses are impacted by behavior and lifestyle modifications like hygiene and environmental sanitation practiced during the COVID-19 pandemic. This study highlights the importance of these universal hygienic practices and their utility in the long-term reduction of monsoon-related illnesses.

Assessment of Risk Factors for COVID-19 in Health Care Workers: A Nested Case-Control Study.

OBJECTIVES: To study the risk factors for SARS-CoV-2 infection in health care workers (HCWs) exposed to COVID-19 patients. MATERIAL AND METHODS: This was a nested case-control study of health care workers(HCWs) in a Dedicated COVID Hospital(DCH). The data collection was done from Dec 2020 to Feb 2021. The study was part of an international multicenter study by the World Health Organisation (WHO).2 The Doctors, nurses, housekeeping staff, clerks, and other staff working in this DCH were considered as HCWs. HCWs working in this DCH with confirmed COVID-19 were recruited as cases and other HCWs working in this DCH in the same Ward/ICU/office without infection were recruited as controls (incidence density sampling). Three controls were taken per case. The questions were in the Likert scale. RESULTS: There were 25 cases and their 75 controls. There was no significant difference between cases and controls with respect to age, sex, occupation, education, and comorbidities and all controls were negative for antibodies at the time of the interview. Most (70%) of the HCWs were doctor by profession followed by nurses (19%). All HCWs were trained in IPC (infection Prevention and Control). Most (96%) HCWs reported that PPE (personal protective equipment) is available in sufficient quantity. There was no significant difference between cases and controls with respect to those having direct contact with the patient's materials, surroundings, and following hand hygiene. CONCLUSION: Adequate availability of PPE, IPC training of HCWs are important for preventing COVID-19 but do not completely reduce risk among HCWs.

Seroprevalence of SARS-CoV-2 Antibodies and Associated Factors in Health Care Workers.

OBJECTIVES: To estimate the seroprevalence of SARS-CoV-2 antibodies among HCWs, and to study the factors associated with this seroprevalence. MATERIAL AND METHODS: A cross-sectional study of HCWs from a Dedicated COVID Hospital was conducted from December 2020 to February 2021. Universal sampling for qualitative testing(by COVID-19 IgG rapid test device by Voxpress) was done and the samples which tested positive were subjected to quantitative testing (chemiluminescent immunoassay) by Serial testing.3 Results: A total of 1005 HCWs were tested out of which 124(12.3%) tested positive by qualitative test and 101(10%) tested positive by both tests. Out of the 1005 HCWs, 155(15.4%) were doctors and 496 (49.4%) were nurses. There was statistically no significant difference between the seropositivity of HCWs with regards to the designation, age, place of work, duration of work in this DCH and Comorbidities. Most HCWs received training in Infection prevention and control(IPC) 988(98.3%), used personal protective equipment(PPE) whenever indicated 997(99.2%), performed hand hygiene before and after handling patients or their material 981(97.6%). Out of 1005 HCWs, 116(11.5%) had a history of COVID-19.The seroprevalence in HCWs not having history of COVID-19 was 74(8.3%). CONCLUSION: Good infection prevention practices can keep the infection rate in HCWs low. HCWs with mild symptoms should also be tested and asymptomatic HCWs should be screened periodically to decrease the spread of COVID-19.