Waning of specific antibodies against Delta and Omicron variants five months after a third dose of BNT162b2 SARS-CoV-2 vaccine in elderly individuals.

The emergence of new SARS-CoV-2 variants, such as the more transmissible Delta and Omicron variants, has raised concerns on efficacy of the COVID-19 vaccines. Here, we examined the waning of antibody responses against different variants following primary and booster vaccination. We found that antibody responses against variants were low following primary vaccination. The antibody response against Omicron was almost non-existent. Efficient boosting of antibody response against all variants, including Omicron, was observed following a third dose. The antibody response against the variants tested was significantly higher at one month following booster vaccination, compared with two months following primary vaccination, for all individuals, including the low antibody responders identified at two months following primary vaccination. The antibody response, for all variants tested, was significantly higher at four months post booster than at five months post primary vaccination, and the proportion of low responders remained low (6-11%). However, there was significant waning of antibody response in more than 95% of individuals at four months, compared to one month following booster. We also observed a robust memory B cell response following booster, which remained higher at four months post booster than prior to booster. However, the memory B cell responses were on the decline for 50% of individuals at four months following booster. Similarly, while the T cell response is sustained, at cohort level, at four months post booster, a substantial proportion of individuals (18.8 - 53.8%) exhibited T cell response at four months post booster that has waned to levels below their corresponding levels before booster. The findings show an efficient induction of immune response against SARS-CoV-2 variants following booster vaccination. However, the induced immunity by the third BNT162b2 vaccine dose was transient. The findings suggest that elderly individuals may require a fourth dose to provide protection against SARS-CoV-2.

Evaluation of the clinical effectiveness of telephone consultation compared to face-to-face consultation in terms of glycaemic control among patients with suboptimally controlled type 2 diabetes: a retrospective cohort study.

OBJECTIVE: With the COVID-19 pandemic, telemedicine has been increasingly deployed in lieu of face-to-face consultations for management of diabetes in primary care. There was a need to evaluate clinical effectiveness of telephone consultations for diabetes management and this study aimed to show whether one-off telephone consultation was inferior or not to face-to-face consultation in terms of glycaemic control among patients with suboptimally controlled type 2 diabetes. DESIGN: Retrospective cohort study. Data of all patients with type 2 diabetes who had a chronic disease consultation during the period 9 April 2020-18 September 2020, and met the study's inclusion and exclusion criteria was obtained from the electronic medical records. SETTING: A primary care clinic in the north-eastern region of Singapore. The clinic's patient population was representative of Singapore's population in terms of gender and age. PARTICIPANTS: 644 patients with type 2 diabetes and glycated haemoglobin (HbA1c) 7.0% and above, aged 21-80 years old. INTERVENTIONS: Participants either underwent telephone or face-to-face consultation for diabetes management. OUTCOME MEASURE: Mean HbA1c change (∆HbA1c) between preintervention and postintervention. RESULTS: Over 4 months, the mean ∆HbA1c was -0.16 percentage points (p.p.) (95% CI -0.26 to -0.07) and -0.11 p.p. (95% CI -0.20 to -0.02) for face-to-face and telephone consultation groups, respectively. The difference in mean ∆HbA1c between the two groups was +0.05 p.p. (95% CI -∞ to 0.16), with the upper limit of the one-sided 95% CI less than the prespecified non-inferiority margin of 0.5 p.p. (p<0.05). In those with HbA1c≥9%, the difference in mean ∆HbA1c was +0.31 p.p. (95% CI -∞ to 0.79), which exceeded the non-inferiority margin. CONCLUSION: For patients with suboptimally controlled type 2 diabetes, one-time telephone consultation was non-inferior to face-to-face consultation in terms of glycaemic control in the short term. However, more studies are required to investigate the long-term effects of telephone consultations and for those with HbA1c≥9%.

Waning of specific antibodies against Delta and Omicron variants five months after a third dose of BNT162b2 SARS-CoV-2 vaccine in elderly individuals

The emergence of new SARS-CoV-2 variants, such as the more transmissible Delta and Omicron variants, has raised concerns on efficacy of the COVID-19 vaccines. Here, we examined the waning of antibody responses against different variants following primary and booster vaccination. We found that antibody responses against variants were low following primary vaccination. The antibody response against Omicron was almost non-existent. Efficient boosting of antibody response against all variants, including Omicron, was observed following a third dose. The antibody response against the variants tested was significantly higher at one month following booster vaccination, compared with two months following primary vaccination, for all individuals, including the low antibody responders identified at two months following primary vaccination. The antibody response, for all variants tested, was significantly higher at four months post booster than at five months post primary vaccination, and the proportion of low responders remained low (6-11%). However, there was significant waning of antibody response in more than 95% of individuals at four months, compared to one month following booster. We also observed a robust memory B cell response following booster, which remained higher at four months post booster than prior to booster. However, the memory B cell responses were on the decline for 50% of individuals at four months following booster. Similarly, while the T cell response is sustained, at cohort level, at four months post booster, a substantial proportion of individuals (18.8 – 53.8%) exhibited T cell response at four months post booster that has waned to levels below their corresponding levels before booster. The findings show an efficient induction of immune response against SARS-CoV-2 variants following booster vaccination. However, the induced immunity by the third BNT162b2 vaccine dose was transient. The findings suggest that elderly individuals may require a fourth dose to provide protection against SARS-CoV-2.

A comparative characterization of SARS-CoV-2-specific T cells induced by mRNA or inactive virus COVID-19 vaccines.

Unlike mRNA vaccines based only on the spike protein, inactivated severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) vaccines should induce a diversified T cell response recognizing distinct structural proteins. Here, we perform a comparative analysis of SARS-CoV-2-specific T cells in healthy individuals following vaccination with inactivated SARS-CoV-2 or mRNA vaccines. Relative to spike mRNA vaccination, inactivated vaccines elicit a lower magnitude of spike-specific T cells, but the combination of membrane, nucleoprotein, and spike-specific T cell response is quantitatively comparable with the sole spike T cell response induced by mRNA vaccine, and they efficiently tolerate the mutations characterizing the Omicron lineage. However, this multi-protein-specific T cell response is not mediated by a coordinated CD4 and CD8 T cell expansion but by selective priming of CD4 T cells. These findings can help in understanding the role of CD4 and CD8 T cells in the efficacy of the different vaccines to control severe COVID-19 after Omicron infection.

Lower vaccine-acquired immunity in the elderly population following two-dose BNT162b2 vaccination is alleviated by a third vaccine dose.

Understanding the impact of age on vaccinations is essential for the design and delivery of vaccines against SARS-CoV-2. Here, we present findings from a comprehensive analysis of multiple compartments of the memory immune response in 312 individuals vaccinated with the BNT162b2 SARS-CoV-2 mRNA vaccine. Two vaccine doses induce high antibody and T cell responses in most individuals. However, antibody recognition of the Spike protein of the Delta and Omicron variants is less efficient than that of the ancestral Wuhan strain. Age-stratified analyses identify a group of low antibody responders where individuals ≥60 years are overrepresented. Waning of the antibody and cellular responses is observed in 30% of the vaccinees after 6 months. However, age does not influence the waning of these responses. Taken together, while individuals ≥60 years old take longer to acquire vaccine-induced immunity, they develop more sustained acquired immunity at 6 months post-vaccination. A third dose strongly boosts the low antibody responses in the older individuals against the ancestral Wuhan strain, Delta and Omicron variants.

Heterologous booster vaccination with CoronaVac following prime vaccination with mRNA vaccine.

Objective: Despite the high vaccine efficacy of mRNA COVID-19 vaccines, there are individuals who developed excessive reactogenic and/or allergic responses after the first mRNA dose and were considered ineligible for further mRNA doses. CoronaVac, an inactivated SARS-CoV-2 vaccine, is recommended in Singapore as an alternative. Methods: Individuals, ineligible for further mRNA vaccines (BNT162b2 or mRNA-1273) because of excessive reactive responses to prime mRNA vaccination, were recruited and offered two doses of CoronaVac as booster vaccination 38-224 days post their mRNA vaccine dose. Individuals who did not develop any excessive reactive responses after the prime mRNA vaccination were also recruited and given another mRNA vaccine as booster vaccination. Blood samples were collected at days 0, 21 and 90 post first CoronaVac dose and mRNA dose, respectively, for analysis. Results: We showed that two CoronaVac booster doses induced specific immunity in these mRNA vaccine-primed individuals. Although the spike-specific antibody response was lower, their memory B cell response against the receptor-binding domain (RBD) of the spike protein was similar, compared with individuals who received two BNT162b2 injections. The spike-specific memory T cell response also increased following CoronaVac booster doses. However, specific immunity against the Omicron variant was low, similar to individuals with two BNT162b2 doses. Conclusion: Our findings showed that while mRNA vaccine-primed individuals can opt for two subsequent doses of CoronaVac, an additional dose may be necessary to achieve protection, especially against newly emerging immune escape variants such as Omicron.

Psychological impact of repeated epidemic exposure on healthcare workers: findings from an online survey of a healthcare workforce exposed to both SARS (severe acute respiratory syndrome) and COVID-19.

OBJECTIVE: To measure the psychological well-being of healthcare workers (HCWs) during this COVID-19 pandemic and examine the experiences of the subgroup of participants who were also HCWs during the 2003 SARS epidemic. DESIGN: Anonymous online survey adapted from a similar study conducted during the SARS epidemic, disseminated from July 2020 to August 2020. SETTING: Nine healthcare institutions across Singapore ranging from primary care, community care, tertiary care and specialised referral centres. PARTICIPANTS: Employees working in the participating healthcare institutions. RESULTS: Of 3828 survey returns, 3616 had at least one completed item on the questionnaire. Majority were female (74.7%), nurses (51.7%), foreign-born (53.2%) and not working in the tertiary care setting (52.1%). The median score on the Impact of Events Scale (IES) was 15 (IQR 23) and 28.2% of the sample scored in the moderate/severe range. 22.7% of the participants were also HCWs during SARS and more than half of them felt safer and better equipped in the current pandemic. 25.2% of SARS HCWs and 25.9% of non-SARS HCWs had moderate/severe IES scores (p=0.904). After adjusting for age, marital status, parity and length of work experience, racial minority groups and living apart from family were independent predictors of high IES regardless of prior SARS epidemic experience. Daily exposure to confirmed or suspect COVID-19 cases increased the odds of high IES for non-SARS HCWs only. CONCLUSIONS AND RELEVANCE: Overall, while 28% of HCWs in our study suffered from significant trauma-related psychological symptoms regardless of prior experience with the SARS epidemic, those with prior experience reported feeling safer and better equipped, finding the workload easier to manage, as well as having more confidence in their healthcare leaders. We recommend for more trauma-informed support strategies for our HCWs especially those from racial minority groups, who are foreign-born and isolated from their families.

Prevalence and patterns of physical activity, sedentary behaviour, and their association with health-related quality of life within a multi-ethnic Asian population.

OBJECTIVE: The study aimed to examine the prevalence and sociodemographic correlates of physical activity and sedentary behaviour in the general population of the multi-ethnic nation of Singapore as part of the Knowledge, Practice and Attitudes towards Diabetes study, a cross-sectional and population-based survey. It also examined the relationship between physical activity, sedentary behaviour, and health-related quality of life (HRQoL). METHODS: Physical activity and sedentary behaviour were assessed via the Global Physical Activity Questionnaire (GPAQ), while physical and mental HRQoL was assessed via the Short Form Health Survey (SF-12v2). Survey weights were employed to account for complex survey design. Multivariable logistic regression models were utilized to examine sociodemographic correlates of physical activity (insufficient vs. sufficient physical activity) and sedentary behaviour (< 7 h/day vs ≥7 h/day). Descriptive statistics were calculated to examine the percentage of time spent in different domains of physical activity. Multivariable linear regressions were conducted to examine the association between physical activity and sedentary behaviour with physical and mental HRQoL. RESULTS: Two thousand eight hundred sixty seven participants recruited from February 2019 to March 2020 (prior to COVID-19 lockdown and related restrictions in Singapore) were included in the analyses. 83.3% of respondents had sufficient physical activity. Age (65 years and above) and income (SGD 2000 to 3999) were associated with a higher likelihood of insufficient physical activity. In contrast, those of Malay ethnicity and having one chronic physical condition were associated with a lower likelihood of insufficient physical activity. 47.7% reported that they had sedentary behaviour of ≥7 h/day. Older age and a primary school education were related to a lower likelihood of sedentary behaviour, while being single, having higher income, obesity, and multimorbidity were associated with higher sedentary behaviour. Insufficient physical activity was significantly associated with lower physical HRQoL but was not significantly associated with mental HRQoL. Sedentary behaviour was not significantly associated with mental or physical HRQoL. CONCLUSION: About 17% of the population did not meet the minimum requirements for physical activity, while around half of the population spent a considerable time being sedentary. As insufficient physical activity was associated with poorer physical HRQoL, policymakers should promote moderate physical activity and encouraging the breaking up of prolonged sedentary periods within the middle- and high-income groups, especially at the workplace. Increased leisure-time exercise should be encouraged for those in the lower- income group.

Readiness and Acceptance of eHealth Services for Diabetes Care in the General Population: Cross-sectional Study.

BACKGROUND: Diabetes management is a growing health care challenge worldwide. eHealth can revolutionize diabetes care, the success of which depends on end user acceptance. OBJECTIVE: This study aims to understand the readiness and acceptance of eHealth services for diabetes care among the general population, perceived advantages and disadvantages of eHealth, and factors associated with eHealth readiness and acceptance in a multiethnic Asian country. METHODS: In this cross-sectional epidemiological study, participants (N=2895) were selected through disproportionate stratified random sampling from a population registry. Citizens or permanent residents of Singapore aged >18 years were recruited. The data were captured through computer-assisted personal interviews. An eHealth questionnaire was administered in one of four local languages (English, Chinese, Malay, or Tamil), as preferred by the participant. Bivariate chi-square analyses were performed to compare the sociodemographic characteristics and perception of advantages and disadvantages of eHealth services between the diabetes and nondiabetes groups. Multivariable logistic regression models were used to determine factors associated with eHealth readiness and acceptance. All analyses were weighted using survey weights to account for the complex survey design. RESULTS: The sample comprised participants with (n=436) and without (n=2459) diabetes. eHealth readiness was low, with 47.3% of the overall sample and 75.7% of the diabetes group endorsing that they were not ready for eHealth (P<.001). The most acceptable eHealth service overall was booking appointments (67.4%). There was a significantly higher preference in the diabetes group for face-to-face sessions for consultation with the clinician (nondiabetes: 83.5% vs diabetes: 92.6%; P<.001), receiving prescriptions (61.9% vs 79.3%; P<.001), referrals to other doctors (51.4% vs 72.2%; P<.001), and receiving health information (34% vs 63.4%; P<.001). The majority of both groups felt that eHealth requires users to be computer literate (90.5% vs 94.3%), does not build clinician-patient rapport compared with face-to-face sessions (77.5% vs 81%), and might not be credible (56.8% vs 64.2%; P=.03). Age (≥35 years), ethnicity (Indian), and lower education status had lower odds of eHealth readiness. Age (≥35 years), ethnicity (Indian), lower education status (primary school), BMI (being underweight), and marital status (being single) were associated with a lower likelihood of eHealth acceptance. Among only those with diabetes, a longer duration of diabetes (4-18 years), higher education (degree or above), and younger age (23-49 years) were associated with eHealth readiness, whereas younger age and income (SGD 2000-3999 [US $1481-$2961]) were associated with acceptance. CONCLUSIONS: Overall, an unfavorable attitude toward eHealth was observed, with a significantly higher number of participants with diabetes reporting their unwillingness to use these services for their diabetes care. Sociodemographic factors associated with acceptance and readiness identified a group of people who were unlikely to accept the technology and thus need to be targeted for eHealth literacy programs to avoid health care disparity. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR2-10.1136/bmjopen-2020-037125.

Health Literacy and Diabetes Knowledge: A Nationwide Survey in a Multi-Ethnic Population.

Health literacy is a key determinant of the public health and health climate of the nation. This study examined the functional health literacy of the nation, factors associated with health literacy, and its relationship with diabetes recognition. This cross-sectional survey recruited participants (N = 2895) who were 18 years and above from a population registry through disproportionate stratified sampling. The Brief Health Literacy Screen and other questionnaires were administered through face-to-face interviews, in one of the four national languages (English, Chinese, Malay or Tamil). The majority (80.5%) had adequate functional health literacy and were able to recognise symptoms of diabetes correctly (83.5% overall; 83.7% and 82.2% in those with adequate and inadequate health literacy, respectively). Those with inadequate health literacy had a higher incidence of chronic conditions (p < 0.001) compared to those with adequate health literacy in bivariate analysis. The majority of the sample had sufficient levels of physical activity (83.3%), and more than half reported an unhealthy lifestyle (57.4%). Older age, Chinese ethnicity, those who were employed, with lower education (secondary or below), and were married had significantly higher odds of inadequate health literacy. Health literacy was not associated with lifestyle, physical activity, chronic conditions and diabetes recognition. Health literacy interventions should focus on the disadvantaged social groups for improving their health literacy.

One Year on: An Overview of Singapore's Response to COVID-19-What We Did, How We Fared, How We Can Move Forward.

Background-One year has passed since the first COVID-19 case in Singapore. This scoping review commemorates Singaporean researchers that have expanded the knowledge on this novel virus. We aim to provide an overview of healthcare-related articles published in peer-reviewed journals, authored by the Singapore research community about COVID-19 during the first year of the pandemic. Methods-This was reported using the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) protocol. It included healthcare-related articles about COVID-19 published between 23 January 2020 and 22 January 2021 with a Singapore-affiliated author. MEDLINE, Embase, Scopus, Web of Science, CINAHL, PsycINFO, Google Scholar, and local journals were searched. The articles were screened independently by two reviewers. Results-The review included 504 articles. Most of the articles narrated the changes to hospital practice (210), while articles on COVID-19 pathology (94) formed most of the non-narrative papers. Publications on public health (61) and the indirect impacts to clinical outcomes (45) were other major themes explored by the research community. The remaining articles detailed the psychological impact of the pandemic (35), adaptations of medical education (30), and narratives of events (14). Conclusion-Amidst a resurgence of community cases involving variant COVID-19 strains, the resources from the research community will provide valuable guidance to navigate these uncertain times.

Perceived stress and associated factors among healthcare workers in a primary healthcare setting: the Psychological Readiness and Occupational Training Enhancement during COVID-19 Time (PROTECT) study.

INTRODUCTION: Disease outbreaks such as the COVID-19 pandemic significantly heighten the psychological stress of healthcare workers (HCWs). The objective of this study was to understand the factors contributing to the perceived stress levels of HCWs in a public primary care setting during the COVID-19 pandemic, including their training, protection and support (TPS), job stress (JS), and perceived stigma and interpersonal avoidance. METHODS: This cross-sectional study using an electronic self-administered questionnaire was conducted at the National Healthcare Group Polyclinics in March 2020. Data was collected anonymously. Analysis was performed using regression modelling. RESULTS: The response rate was 69.7% (n = 1,040). The mean perceived stress level of HCWs in various departments ranged from 17.2 to 20.3. Respondents who reported higher perceived stress were those who made alternative living arrangements, were more affected by the current pandemic, reported higher JS and were Muslims. Respondents who reported lower perceived stress were those who had been through the severe acute respiratory syndrome epidemic in 2003 and H1N1 pandemic in 2009 as HCWs, and those who had higher confidence in the organisation's TPS. CONCLUSION: All HCWs, regardless of their scope of work, were similarly stressed by the current pandemic compared to the general population. Improving the confidence of HCWs in their training, protection and the support of personal protective equipment, and retaining experienced HCWs who can provide advice and emotional support to younger colleagues are important. Adequate psychological support for HCWs in the pandemic can be transformed into reserves of psychological resilience for future disease outbreaks.

Video Consultations for Older Adults With Multimorbidity During the COVID-19 Pandemic: Protocol for an Exploratory Qualitative Study.

BACKGROUND: Multimorbidity, the coexistence of multiple chronic conditions in an individual, is a growing public health challenge. Amidst the COVID-19 pandemic, physical distancing remains an indispensable measure to limit the spread of the virus. This pertains especially to those belonging to high-risk groups, namely older adults with multimorbidity. In-person visits are discouraged for this cohort; hence, there is a need for an alternative form of consultation such as video consultations to continue the provision of care. OBJECTIVE: The potential of video consultations has been explored in several studies. However, the emergence of COVID-19 presents us with an unprecedented opportunity to explore the use of this technological innovation in a time when physical distancing is imperative. This study will evaluate the sustainability of video consultations on a micro-, meso-, and macro-level by assessing the views of patients, physicians, and organizational and national policymakers, respectively. METHODS: The NASSS (nonadoption, abandonment, scale-up, spread, and sustainability) framework was designed as a guide for the development of health care technologies. In this study, the implementation of and experiences related to video consultations will be studied using the NASSS framework. Individual in-depth interviews or focus group discussions will be conducted with participants using the Zoom platform. Data will be analyzed by at least two investigators trained in qualitative methodology, organized thematically, and coded in two phases-an initial phase and a focused selective phase. All disagreements will be resolved by consulting the larger research team until consensus is reached. RESULTS: This study was approved for funding from the Geriatric Education and Research Institute. Ethics approval was obtained from the National Healthcare Group Domain Specific Review Board (reference #2020/00760). Study recruitment commenced in July 2020. The results of the data analysis are expected to be available by the end of the year. CONCLUSIONS: This study aims to evaluate the adoption and sustainability of video consultations for older adults with multimorbidity during the pandemic as well as post COVID-19. The study will yield knowledge that will challenge the current paradigm on how care is being delivered for community-dwelling older adults with multimorbidity. Findings will be shared with administrators in the health care sector in order to enhance the safety and quality of these video consultations to improve patient care for this group of population. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/22679.