Adverse Events Following Immunization with mRNA and Viral Vector Vaccines in Individuals with Previous SARS-CoV-2 Infection from the Canadian National Vaccine Safety Network.

BACKGROUND: Adults previously infected with SARS-CoV-2 develop short-term immunity and may have increased reactogenicity to COVID-19 vaccines. This prospective, multi-center active surveillance cohort study examined the short-term safety of COVID-19 vaccines in adults with a prior history of SARS-CoV-2. METHODS: Canadian adults vaccinated between December 22, 2020 and November 27, 2021 were sent an electronic questionnaire 7 days post dose 1, dose 2 and dose 3 vaccination. The main outcome was health events occurring in the first 7 days after each vaccination that prevented daily activities, resulted in work absenteeism or required a medical consultation, including hospitalization. RESULTS: Among 684,998 vaccinated individuals, 2.6% (18,127/684,998) reported a prior history of SARS-CoV-2 infection a median of 4 months (interquartile range 2-6 months) previously. After dose 1, individuals with moderate (bedridden) to severe (hospitalized) COVID-19 who received BNT162b2, mRNA1273 or ChAdox1-S vaccines had higher odds of a health event preventing daily activities, resulting in work absenteeism or requiring medical consultation; adjusted odds ratio (AOR) 3.96 (95% CI 3.67-4.28) for BNT162b2, 5.01 (4.57-5.50) for mRNA1273 and 1.84 (1.54-2.20) for ChAdox1-S compared to no infection. Following dose 2 and 3, the greater risk associated with previous infection was also present but attenuated compared to dose 1. For all doses, the association was lower or absent after mild or asymptomatic infection. CONCLUSION: Adults with moderate or severe previous SARS-CoV-2 infection were more likely to have a health event sufficient to impact routine activities or require medical assessment in the week following each vaccine doses.

Validation and implementation of group electronic hand hygiene monitoring across twenty-four critical care units.

OBJECTIVES: An accurate estimate of the average number of hand hygiene opportunities per patient hour (HHO rate) is required to implement group electronic hand hygiene monitoring systems (GEHHMSs). We sought to identify predictors of HHOs to validate and implement a GEHHMS across a network of critical care units. DESIGN: Multicenter, observational study (10 hospitals) followed by quality improvement intervention involving 24 critical care units across 12 hospitals in Ontario, Canada. METHODS: Critical care patient beds were randomized to receive 1 hour of continuous direct observation to determine the HHO rate. A Poisson regression model determined unit-level predictors of HHOs. Estimates of average HHO rates across different types of critical care units were derived and used to implement and evaluate use of GEHHMS. RESULTS: During 2,812 hours of observation, we identified 25,417 HHOs. There was significant variability in HHO rate across critical care units. Time of day, day of the week, unit acuity, patient acuity, patient population and use of transmission-based precautions were significantly associated with HHO rate. Using unit-specific estimates of average HHO rate, aggregate HH adherence was 30.0% (1,084,329 of 3,614,908) at baseline with GEHHMS and improved to 38.5% (740,660 of 1,921,656) within 2 months of continuous feedback to units (P < .0001). CONCLUSIONS: Unit-specific estimates based on known predictors of HHO rate enabled broad implementation of GEHHMS. Further longitudinal quality improvement efforts using this system are required to assess the impact of GEHHMS on both HH adherence and clinical outcomes within critically ill patient populations.

Comparative-effectiveness research of COVID-19 treatment: a rapid scoping review.

OBJECTIVES: The COVID-19 pandemic has stimulated growing research on treatment options. We aim to provide an overview of the characteristics of studies evaluating COVID-19 treatment. DESIGN: Rapid scoping review DATA SOURCES: Medline, Embase and biorxiv/medrxiv from inception to 15 May 2021. SETTING: Hospital and community care. PARTICIPANTS: COVID-19 patients of all ages. INTERVENTIONS: COVID-19 treatment. RESULTS: The literature search identified 616 relevant primary studies of which 188 were randomised controlled trials and 299 relevant evidence syntheses. The studies and evidence syntheses were conducted in 51 and 39 countries, respectively.Most studies enrolled patients admitted to acute care hospitals (84%), included on average 169 participants, with an average age of 60 years, study duration of 28 days, number of effect outcomes of four and number of harm outcomes of one. The most common primary outcome was death (32%).The included studies evaluated 214 treatment options. The most common treatments were tocilizumab (11%), hydroxychloroquine (9%) and convalescent plasma (7%). The most common therapeutic categories were non-steroidal immunosuppressants (18%), steroids (15%) and antivirals (14%). The most common therapeutic categories involving multiple drugs were antimalarials/antibiotics (16%), steroids/non-steroidal immunosuppressants (9%) and antimalarials/antivirals/antivirals (7%). The most common treatments evaluated in systematic reviews were hydroxychloroquine (11%), remdesivir (8%), tocilizumab (7%) and steroids (7%).The evaluated treatment was in favour 50% and 36% of the evaluations, according to the conclusion of the authors of primary studies and evidence syntheses, respectively. CONCLUSIONS: This rapid scoping review characterised a growing body of comparative-effectiveness primary studies and evidence syntheses. The results suggest future studies should focus on children, elderly ≥65 years of age, patients with mild symptoms, outpatient treatment, multimechanism therapies, harms and active comparators. The results also suggest that future living evidence synthesis and network meta-analysis would provide additional information for decision-makers on managing COVID-19.

Safety of COVID-19 vaccines in pregnancy: a Canadian National Vaccine Safety (CANVAS) network cohort study.

BACKGROUND: Pregnant individuals have been receiving COVID-19 vaccines following pre-authorisation clinical trials in non-pregnant people. This study aimed to determine the frequency and nature of significant health events among pregnant females after COVID-19 vaccination, compared with unvaccinated pregnant controls and vaccinated non-pregnant individuals. METHODS: We did an observational cohort study, set in seven Canadian provinces and territories including Ontario, Quebec, British Columbia, Alberta, Nova Scotia, Yukon, and Prince Edward Island. Eligibility criteria for vaccinated individuals were a first dose of a COVID-19 vaccine within the previous 7 days; an active email address and telephone number; ability to communicate in English or French; and residence in the aforementioned provinces or territories. Study participants were pregnant and non-pregnant females aged 15-49 years. Individuals were able to participate as controls if they were unvaccinated and fulfilled the other criteria. Data were collected primarily by self-reported survey after both vaccine doses, with telephone follow-up for those reporting any medically attended event. Participants reported significant health events (new or worsening of a health event sufficient to cause work or school absenteeism, medical consultation, or prevent daily activities) occurring within 7 days of vaccination or within the past 7 days for unvaccinated individuals. We employed multivariable logistic regression to examine significant health events associated with mRNA vaccines, adjusting for age group, previous SARS-CoV-2 infection, and trimester, as appropriate. FINDINGS: As of Nov 4, 2021, 191 360 women aged 15-49 years with known pregnancy status had completed the first vaccine dose survey and 94 937 had completed the second dose survey. 180 388 received one dose and 94 262 received a second dose of an mRNA vaccine, with 5597 pregnant participants receiving dose one and 3108 receiving dose two, and 174 765 non-pregnant participants receiving dose one and 91 131 receiving dose two. Of 6179 included unvaccinated control participants, 339 were pregnant and 5840 were not pregnant. Overall, 226 (4·0%) of 5597 vaccinated pregnant females reported a significant health event after dose one of an mRNA vaccine, and 227 (7·3%) of 3108 after dose two, compared with 11 (3·2%) of 339 pregnant unvaccinated females. Pregnant vaccinated females had an increased odds of a significant health event within 7 days of the vaccine after dose two of mRNA-1273 (adjusted odds ratio [aOR] 4·4 [95% CI 2·4-8·3]) compared with pregnant unvaccinated controls within the past 7 days, but not after dose one of mRNA-1273 or any dose of BNT162b2. Pregnant vaccinated females had decreased odds of a significant health event compared with non-pregnant vaccinated females after both dose one (aOR 0·63 [95% CI 0·55-0·72]) and dose two (aOR 0·62 [0·54-0·71]) of any mRNA vaccination. There were no significant differences in any analyses when restricted to events which led to medical attention. INTERPRETATION: COVID-19 mRNA vaccines have a good safety profile in pregnancy. These data can be used to appropriately inform pregnant people regarding reactogenicity of COVID-19 vaccines during pregnancy, and should be considered alongside effectiveness and immunogenicity data to make appropriate recommendations about best use of COVID-19 vaccines in pregnancy. FUNDING: Canadian Institutes of Health Research, Public Health Agency of Canada.

Comparative-effectiveness research of COVID-19 treatment: a rapid scoping review

Objectives The COVID-19 pandemic has stimulated growing research on treatment options. We aim to provide an overview of the characteristics of studies evaluating COVID-19 treatment. Design Rapid scoping review Data sources Medline, Embase and biorxiv/medrxiv from inception to 15 May 2021. Setting Hospital and community care. Participants COVID-19 patients of all ages. Interventions COVID-19 treatment. Results The literature search identified 616 relevant primary studies of which 188 were randomised controlled trials and 299 relevant evidence syntheses. The studies and evidence syntheses were conducted in 51 and 39 countries, respectively. Most studies enrolled patients admitted to acute care hospitals (84%), included on average 169 participants, with an average age of 60 years, study duration of 28 days, number of effect outcomes of four and number of harm outcomes of one. The most common primary outcome was death (32%). The included studies evaluated 214 treatment options. The most common treatments were tocilizumab (11%), hydroxychloroquine (9%) and convalescent plasma (7%). The most common therapeutic categories were non-steroidal immunosuppressants (18%), steroids (15%) and antivirals (14%). The most common therapeutic categories involving multiple drugs were antimalarials/antibiotics (16%), steroids/non-steroidal immunosuppressants (9%) and antimalarials/antivirals/antivirals (7%). The most common treatments evaluated in systematic reviews were hydroxychloroquine (11%), remdesivir (8%), tocilizumab (7%) and steroids (7%). The evaluated treatment was in favour 50% and 36% of the evaluations, according to the conclusion of the authors of primary studies and evidence syntheses, respectively. Conclusions This rapid scoping review characterised a growing body of comparative-effectiveness primary studies and evidence syntheses. The results suggest future studies should focus on children, elderly ≥65 years of age, patients with mild symptoms, outpatient treatment, multimechanism therapies, harms and active comparators. The results also suggest that future living evidence synthesis and network meta-analysis would provide additional information for decision-makers on managing COVID-19.

The Canadian National Vaccine Safety Network: surveillance of adverse events following immunisation among individuals immunised with the COVID-19 vaccine, a cohort study in Canada.

INTRODUCTION: COVID-19 vaccines require enhanced safety monitoring after emergency approval. The Canadian National Vaccine Safety Network monitors the safety of COVID-19 vaccines and provides enhanced monitoring for healthy, auto-immune, immunocompromised, pregnant and breastfeeding populations and allows for the detection of safety signals. METHODS AND ANALYSIS: Online participant reporting of health events in vaccinated and unvaccinated individuals 12 years of age and older is captured in three surveys: 1 week after dose 1, 1 week after dose 2 and 7 months after dose 1. Medically attended events are followed up by telephone. The number, percentage, rate per 10 000 and incident rate ratios with 95% CIs are calculated by health event, vaccine type, sex and in 10-year age groups. ETHICS AND DISSEMINATION: Each study site has Research Ethics Board approvals for the project (UBC Children's & Women's, CIUSSS de l'Estrie-CHUS, Health PEI, Conjoint Health Research Ethics Board, University of Calgary and Alberta Health Services, IWK Health, Unity Health Toronto and CHU de Québec-Université Laval Research Ethics Boards). Individuals are invited to participate in this active surveillance and electronic consent is given before proceeding to each survey. Weekly reports are shared with public health and posted on the study website. At least one peer-reviewed manuscript is produced.

Impact of COVID-19 on hospital hand hygiene performance: a multicentre observational study using group electronic monitoring.

BACKGROUND: Reliable reports on hand hygiene performance throughout the COVID-19 pandemic are lacking as most hospitals continue to rely on direct observation to measure this quality indicator. Using group electronic hand hygiene monitoring, we sought to assess the impact of COVID-19 on adherence to hand hygiene. METHODS: Across 12 Ontario hospitals (5 university and 7 community teaching hospitals), a group electronic hand hygiene monitoring system was installed before the pandemic to provide continuous measurement of hand hygiene adherence across 978 ward and 367 critical care beds. We performed an interrupted time-series study of institutional hand hygiene adherence in association with a COVID-19 inpatient census and the Ontario daily count of COVID-19 cases during a baseline period (Nov. 1, 2019, to Feb. 29, 2020), the pre-peak period of the first wave of the pandemic (Mar. 1 to Apr. 24, 2020), and the post-peak period of the first wave (Apr. 25 to July 5, 2020). We used a Poisson regression model to assess the association between the hospital COVID-19 census and institutional hand hygiene adherence while adjusting for the correlation within inpatient units. RESULTS: At baseline, the rate of hand hygiene adherence was 46.0% (6 325 401 of 13 750 968 opportunities) and this improved beginning in March 2020 to a daily peak of 79.3% (66 640 of 84 026 opportunities) on Mar. 30, 2020. Each patient admitted with COVID-19 was associated with improved hand hygiene adherence (incidence rate ratio [IRR] 1.0621, 95% confidence interval [CI] 1.0619-1.0623). Increasing Ontario daily case count was similarly associated with improved hand hygiene (IRR 1.0026, 95% CI 1.0021-1.0032). After peak COVID-19 community and inpatient numbers, hand hygiene adherence declined and returned to baseline. INTERPRETATION: The first wave of the COVID-19 pandemic was associated with significant improvement in hand hygiene adherence, measured using a group electronic monitoring system. Future research should seek to determine whether strategies that focus on health care worker perception of personal risk can achieve sustainable improvements in hand hygiene performance.

Province-Wide Prevalence Testing for SARS-CoV-2 of In-Center Hemodialysis Patients and Staff in Ontario, Canada: A Cross-Sectional Study.

BACKGROUND: People receiving in-center hemodialysis face a high risk for contracting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and experience poor outcomes. During the first wave of the coronavirus disease 2019 (COVID-19) pandemic in Ontario (between March and June 2020), it was unclear whether asymptomatic or presymptomatic cases were common and whether widespread testing of all dialysis patients and staff would identify cases earlier and prevent transmission. Ontario has a population of about 14.5 million. Approximately 8900 people receive dialysis across 102 in-center dialysis units. OBJECTIVE: The objective of this study was to determine participation rates for patients and staff in point prevalence testing in dialysis units across the province and to determine the prevalence of asymptomatic or presymptomatic infection. DESIGN: Cross-sectional study design. SETTING: In-center hemodialysis units at 27 renal programs across Ontario. PARTICIPANTS: Patients and staff in in-center dialysis units in Ontario. MEASUREMENTS: Participation rates, demographic data, SARS-CoV-2 positivity rates, and COVID-19-related symptom data. METHODS: From June 8 to 30, 2020, all in-center dialysis patients and staff in the Province of Ontario were requested to undergo a symptom screening assessment and nasopharyngeal swab. Testing was done using polymerase chain reaction to detect SARS-CoV-2. A standardized questionnaire of atypical and typical COVID-19-related symptoms was administered to patients, to assess for new or worsening COVID-19-related symptoms. RESULTS: Patient participation was 83% (7155 of 8612) of which 15 tests were positive: less than 5 (<0.07%) were new positive cases, 7 were false positive, and the remaining were recovered positives. Half of the new positive cases had symptoms. Common symptoms reported included fatigue (4%), falls (4%), runny nose (3%), dyspnea (3%), and cough (3%). Staff participation was 49% (2109 of 4325), and less than 5 (<0.24%) were asymptomatic positive. LIMITATIONS: As point prevalence testing was voluntary, not all patients and staff participated. Lower participation rate may be due to decreasing new cases in Ontario, and testing or pandemic fatigue, among other factors. This study did not use serology to identify prior infections because it was not widely available in Ontario. With respect to the standardized symptom questionnaire, it was only available in English and French and could not be tested due to the urgency of the initiative. CONCLUSIONS: Participation among patients in point prevalence testing was good, but participation among staff was relatively low. Asymptomatic positivity in the dialysis patient and staff population was rare during the first wave of the COVID-19 pandemic in Ontario.

Preventing the transmission of COVID-19 and other coronaviruses in older adults aged 60 years and above living in long-term care: a rapid review.

BACKGROUND: The objective of this review was to examine the current guidelines for infection prevention and control (IPAC) of coronavirus disease-19 (COVID-19) or other coronaviruses in adults 60 years or older living in long-term care facilities (LTCF). METHODS: EMBASE, MEDLINE, Cochrane library, pre-print servers, clinical trial registries, and relevant grey literature sources were searched until July 31, 2020, using database searching and an automated method called Continuous Active Learning® (CAL®). All search results were processed using CAL® to identify the most likely relevant citations that were then screened by a single human reviewer. Full-text screening, data abstraction, and quality appraisal were completed by a single reviewer and verified by a second. RESULTS: Nine clinical practice guidelines (CPGs) were included. The most common recommendation in the CPGs was establishing surveillance and monitoring systems followed by mandating the use of PPE; physically distancing or cohorting residents; environmental cleaning and disinfection; promoting hand and respiratory hygiene among residents, staff, and visitors; and providing sick leave compensation for staff. CONCLUSIONS: Current evidence suggests robust surveillance and monitoring along with support for IPAC initiatives are key to preventing the spread of COVID-19 in LTCF. However, there are significant gaps in the current recommendations especially with regard to the movement of staff between LTCF and their role as possible transmission vectors. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42020181993.

COVID-19 Outbreak in an Urban Hemodialysis Unit.

RATIONALE & OBJECTIVE: Hemodialysis patients are at increased risk for coronavirus disease 2019 (COVID-19) transmission due in part to difficulty maintaining physical distancing. Our hemodialysis unit experienced a COVID-19 outbreak despite following symptom-based screening guidelines. We describe the course of the COVID-19 outbreak and the infection control measures taken for mitigation. STUDY DESIGN: Retrospective cohort study. SETTING & PARTICIPANTS: 237 maintenance hemodialysis patients and 93 hemodialysis staff at a single hemodialysis center in Toronto, Canada. EXPOSURE: Universal screening of patients and staff for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). OUTCOMES: The primary outcome was detection of SARS-CoV-2 in nasopharyngeal samples from patients and staff using reverse transcriptase-polymerase chain reaction (RT-PCR). ANALYTICAL APPROACH: Descriptive statistics were used for clinical characteristics and the primary outcome. RESULTS: 11 of 237 (4.6%) hemodialysis patients and 11 of 93 (12%) staff members had a positive RT-PCR test result for SARS-CoV-2. Among individuals testing positive, 12 of 22 (55%) were asymptomatic at time of testing and 7 of 22 (32%) were asymptomatic for the duration of follow-up. One patient was hospitalized at the time of SARS-CoV-2 infection and 4 additional patients with positive test results were subsequently hospitalized. 2 (18%) patients required admission to the intensive care unit. After 30 days' follow-up, no patients had died or required mechanical ventilation. No hemodialysis staff required hospitalization. Universal droplet and contact precautions were implemented during the outbreak. Hemodialysis staff with SARS-CoV-2 infection were placed on home quarantine regardless of symptom status. Patients with SARS-CoV-2 infection, including asymptomatic individuals, were treated with droplet and contact precautions until confirmation of negative SARS-CoV-2 RT-PCR test results. Analysis of the outbreak identified 2 index cases with subsequent nosocomial transmission within the dialysis unit and in shared shuttle buses to the hemodialysis unit. LIMITATIONS: Single-center study. CONCLUSIONS: Universal SARS-CoV-2 testing and universal droplet and contact precautions in the setting of an outbreak appeared to be effective in preventing further transmission.