The temporal evolution in disease phenotype of COVID-19 hospitalisation, intensive care and case fatality rates in cancer patients across the United Kingdom (UKCCP)

Background: People living with cancer are reported to be at increased risk of hospitalization and death following infection with acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This is proposed to be dependent on a combination of intrinsic patient and cancer factors such as cancer subtype, and emerging SARS-CoV-2 variants with differing pathogenicity. However, COVID-19 phenotype evolution across the pandemic from 2020 has not yet been systematically evaluated in cancer patients. Method(s): This study is a population-scale real-world evaluation of Coronavirus outcomes in the United Kingdom for cancer patients from 1st November 2020-31st August 2022. The cancer cohort comprises individuals from Public Health England's national cancer dataset, excluding individuals less than 18 years old. Case-outcome rates, including hospitalization, intensive care and casefatality rates were used to assess the evolution in disease phenotype of COVID-19 in cancer patients. Multivariable logistic regression models were fitted to compare risk of Coronavirus outcomes in the cancer cohort relative to the non-cancer population during the Omicron wave in 2022. Result(s): The cancer cohort comprised of 198,819 positive SARS-CoV-2 tests from 127,322 individual infections. Coronavirus case-outcome rates were evaluated by reference to 18,188,573 positive tests from 15,801,004 individual infections in the non-cancer population. From 2020 to 2022, the SARS-CoV-2 disease phenotype became less severe in both patients with cancer and the non-cancer population, though cancer patients remain at higher risk. In 2022, the relative risk of Coronavirus hospital admission, inpatient hospitalization, intensive care admission and mortality in cancer patients was 3.02x, 2.10x, 2.53x and 2.54x compared to the non-cancer population following multivariable adjustment, respectively. Higher risk of hospital admission and inpatient hospitalization were associated with receipt of B/T cell antibody and/or targeted therapy which also corresponded with an increased risk of Coronavirus mortality. Conclusion(s): The disease phenotype of SARS-CoV-2 in cancer patients in 2022 has evolved significantly from the disease phenotype in 2020. Direct effects of the virus in terms of SARS-CoV-2 hospitalization, intensive care and case fatality rates have fallen significantly over time. However, relative to the general population, people living with cancer and hematological malignancies remain at elevated risk. In order to mitigate the indirect effects of the SARS-CoV-2 pandemic in terms of disruption to cancer care, there should be increased focus on preventative measures. Used in conjunction with vaccination and early treatment programs, this will maximize quality of life for those with cancer during the ongoing pandemic and ensure the best cancer outcomes.

Systematic Review of the Clinical Effectiveness of Tixagevimab/Cilgavimab for Prophylaxis of Covid-19 in Immunocompromised Patients

Background/Aims Immunocompromised patients have a reduced ability to generate antibodies after COVID-19 vaccination, and are at a high risk of SARSPOSTERS CoV-2 infection, complications and mortality. Tixagevimab/Cilgavimab (Evusheld) is a combination of two monoclonal antibodies which bind to the SARS-CoV-2 spike protein, preventing the virus entering human cells. Tixagevimab/Cilgavimab has been approved as COVID-19 prophylaxis for immunocompromised individuals, and is being used in over 32 different countries. The phase III PROVENT clinical trial found that high-risk participants prophylactically administered Tixagevimab/Cilgavimab had a significantly reduced risk of COVID- 19 infection after three and six months compared to controls. However, the PROVENT trial was conducted prior to the SARS-CoV- 2 Omicron wave, and did not include participants who had been previously vaccinated or infected. This systematic review provides an updated summary of the real-world clinical evidence of the efficacy of Tixagevimab/Cilgavimab for immunocompromised patients. The review reports breakthrough COVID-19 infections as its primary outcome. COVID-19-related hospitalisations, ITU admissions and mortality were included as secondary outcomes. Methods Two independent reviewers conducted electronic searches of PubMed and Medxriv, on 03/08/22 and 01/10/22. Clinical studies which reported the primary outcome of breakthrough COVID-19 infections after Tixagevimab/Cilgavimab administration were included. Clinical effectiveness was determined using the case-control clinical effectiveness methodology. Odds ratios and 95% confidence intervals (CI) between intervention and control groups were also calculated. The GRADE tool was used to assess the level of certainty for the primary outcome. Results 17 clinical studies were included in the review, with a total of 24,773 immunocompromised participants from across the world, of whom 10,775 received Tixagevimab/Cilgavimab. One randomised controlled trial, ten retrospective cohort studies (two of which were preprints) and six prospective cohort studies (one preprint) were included. The majority of studies reported clinical outcomes during the SARS-CoV-2 Omicron wave. Six studies compared a Tixagevimab/Cilgavimab intervention group to a control group. Reasons for participant immunocompromise included rheumatology patients treated with immunosuppressant drugs, transplant recipients and those with malignancies. Overall, the clinical effectiveness of prophylactic Tixagevimab/Cilgavimab against COVID- 19 breakthrough infection was 40.47% (CI 29.82-49.67;p<0.0001), COVID-19 hospitalisation- 69.23% (CI: 50.78-81.64;p<0.00001), ITU admission- 87.89% (CI: 47.12-98.66;p=0.0008), all-cause mortality- 81.29% (66.93-90.28;p<0.0001 and COVID-19-specifc mortality- 86.36% (CI:-6.21-99.70;p=0.0351). Conclusion There is a growing body of real-world evidence validating the original PROVENT phase III study regarding the clinical effectiveness of Tixagevimab/Cilgavimab as prophylaxis for immunocompromised groups, notably demonstrating effectiveness during the Omicron wave. This systematic review demonstrates the significant clinical effectiveness of prophylactic Tixagevimb/Cilgavimab at reducing COVID-19 infection, hospitalisation, ITU admission and mortality for immunosuppressed individuals. It is critically important that largerscale and better-controlled studies are performed to highlight the significant clinical benefit of prophylactic antibody treatment in immunocompromised groups.

Quantifying the reduction of airborne infectious viral load using a ventilated patient hood.

BACKGROUND: Healthcare workers treating SARS-CoV-2 patients are at risk of infection by respiratory exposure to patient-emitted, virus-laden aerosols. Source control devices such as ventilated patient isolation hoods have been shown to limit the dissemination of non-infectious airborne particles in laboratory tests, but data on their performance in mitigating the airborne transmission risk of infectious viruses are lacking. AIM: We used an infectious airborne virus to quantify the ability of a ventilated hood to reduce infectious virus exposure in indoor environments. METHODS: We nebulized 109 plaque forming units (pfu) of bacteriophage PhiX174 virus into a ∼30-m3 room when the hood was active or inactive. The airborne concentration of infectious virus was measured by BioSpot-VIVAS and settle plates using plaque assay quantification on the bacterial host Escherichia coli C. The airborne particle number concentration (PNC) was also monitored continuously using an optical particle sizer. FINDINGS: The median airborne viral concentration in the room reached 1.41 × 105 pfu/m3 with the hood inactive. When active, the hood reduced infectious virus concentration in air samples by 374-fold. The deposition of infectious virus on the surface of settle plates was reduced by 87-fold. This was associated with a 109-fold reduction in total airborne particle number escape rate. CONCLUSION: A personal ventilation hood significantly reduced airborne particle escape, considerably lowering infectious virus contamination in an indoor environment. Our findings support the further development of source control devices to mitigate nosocomial infection risk among healthcare workers exposed to airborne viruses in clinical settings.

Reactogenicity among Lactating Mother and Baby Dyads Following Covid-19 Vaccines in Two Multi-Ethnic Asian Countries

Aims At the time of publication, there was limited evidence on outcomes of breastfeeding mother-child dyads on breastfeeding after COVID-19 vaccination. The aim of this study is to systematically quantify the incidence of local and systemic adverse events in lactating women and their children to allow clinicians to appropriately counsel lactating women on the risks-benefit ratio of WHO-approved COVID-19 vaccinations. Methods A cross sectional survey was conducted from 14th August 2021 to 5th January 2022 in Singapore and Malaysia. Data including demographic information, maternal and child symptoms, and vaccine history were collected through an online questionnaire. The survey was distributed online through social media and advertisements. Women more than 21 years of age who received at least one dose of the WHOapproved COVID-19 vaccines Pfizer-BioNTech, Moderna, AstraZeneca, Sinovac while pregnant or lactating were eligible for the survey. Results Responses of 2043 breastfeeding mothers were analysed. 1747 mothers received mRNA vaccines and 296 mothers received non-mRNA vaccines. Overall in terms of maternal reactogenicity, 79.3% and 79.5% of mothers reported any reactions to the first and second dose respectively, primarily local reactions (64.1% dose 1, 57.0% dose 2). 91.8% of mothers breastfed their child uninterrupted after receiving the COVID-19 vaccination. 89.2% of breastfed infants had no symptoms reported following maternal COVID-19 vaccination. More than half (54.8%) of lactating respondents reported no change in milk supply or production. Among those experiencing changes in lactation, symptoms lasted for an average of 4.2 +/- 6.9 days. Conclusion Our findings suggest that the vaccine resulted in minimal disruption of lactation or adverse impact on the breastfed child in mothers receiving COVID-19 vaccination. Breastfeeding mothers may experience a change in breast milk supply when receiving COVID-19 vaccinations, which may be mitigated by proactive measures to ensure adequate rest and hydration. There is minimal severe reactogenicity with COVID-19 vaccination in lactating motherchild dyads.