Scottish COVID CAncer iMmunity Prevalence (SCCAMP): A longitudinal study of patients with cancer receiving active anti-cancer treatment during the COVID-19 pandemic

Background: Cancer and systemic anti-cancer treatment (SACT) have been identified as possible risk factors for infection and related severe illness associated with SARS-CoV-2 virus as a consequence of immune suppression. The Scottish COVID CAncer iMmunity Prevalence (SCCAMP) study aimed to characterise the incidence and outcomes of SARS-Cov-2 infection in patients undergoing active anticancer treatment during the COVID-19 pandemic and their antibody response following vaccination. Methods: Eligible patients were those attending secondary care for active anti-cancer treatment for a solid tumour. Blood samples were taken for total SARS-CoV-2 antibody assay (Siemens) at baseline and after 1.5, 3, 6 and 12 months. Data on COVID-19 infection, vaccination, cancer type, treatment and outcome (patient death) was obtained from routine electronic health records. Results: The study recruited 766 eligible participants between 28th May 2020 and 31st October 2021. During the study period there were 174 deaths (22%). The median age was 63 years, and 67% were female. Most received cytotoxic chemotherapy (79%), with the remaining 14% receiving immunotherapy and 7% receiving another form of anti-cancer therapy (radiotherapy, other systemic anti-cancer treatment). 48 (6.3%) tested positive for SARS-CoV-2 by PCR during the study period. The overall infection rate matched that of the local adult general population until May 2021, after which population levels appeared higher than the study population. Antibody testing detected additional evidence of infection prior to vaccination, taking the total number to 58 (7.6%). There was no significant difference in SARS-CoV-2 PCR positive test rates based on type of anti-cancer treatment. Mortality rates were similar between those who died within 90 days of a positive SARS-CoV-2 PCR and those with no positive PCR (10.4% vs 10.6%). Death from all causes was lowest among vaccinated patients, and of the patients who had a positive SARS-CoV-2 PCR at any time, all of those who died during the study period were unvaccinated. Multivariate analysis correcting for age, gender, socioeconomic status, Charlson co-morbidity score and number of previous medications revealed that vaccination was associated with a significantly lower infection rate regardless of treatment with chemotherapy or immunotherapy with hazard ratios of 0.307 (95% CI 0.144-0.6548) or 0.314 (95% CI 0.041-2.367) in vaccinated patients respectively. Where antibody data was available, 96.3% of patients successfully raised SARSCoV-2 antibodies at a time point after vaccination. This was unaffected by treatment type. Conclusions: SCCAMP provides real-world evidence that patients with cancer undergoing SACT have a high antibody response and protection from SARS-CoV-2 infection following COVID-19 vaccination.

National population prevalence of antibodies to SARS-CoV-2 in Scotland during the first and second waves of the COVID-19 pandemic.

OBJECTIVES: Studies that measure the prevalence of antibodies to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ('seroprevalence') are essential to understand population exposure to SARS-CoV-2 among symptomatic and asymptomatic individuals. We aimed to measure seroprevalence in the Scottish population over the course of the COVID-19 pandemic - from before the first recorded case in Scotland through to the second pandemic wave. STUDY DESIGN: The study design of this study is serial cross sectional. METHODS: We tested 41,477 residual samples retrieved from primary and antenatal care settings across Scotland for SARS-CoV-2 antibodies over a 12-month period from December 2019-December 2020 (before rollout of COVID-19 vaccination). Five-weekly rolling seroprevalence estimates were adjusted for the sensitivity and specificity of the assays and weighted to reference populations. Temporal trends in seroprevalence estimates and weekly SARS-CoV-2 notifications were compared. RESULTS: Five-weekly rolling seroprevalence rates were 0% until the end of March, when they increased contemporaneously with the first pandemic wave. Seroprevalence rates remained stable through the summer (range: 3%-5%) during a period of social restrictions, after which they increased concurrently with the second wave, reaching 9.6% (95% confidence interval [CI]: 8.4%-10.8%) in the week beginning 28th December in 2020. Seroprevalence rates were lower in rural vs. urban areas (adjusted odds ratio [AOR]: 0.70, 95% CI: 0.61-0.79) and among individuals aged 20-39 years and 60 years and older (AOR: 0.74, 95% CI: 0.64-0.86; AOR: 0.80, 95% CI: 0.69-0.91, respectively) relative to those aged 0-19 years. CONCLUSIONS: After two waves of the COVID-19 pandemic, less than one in ten individuals in the Scottish population had antibodies to SARS-CoV-2. Seroprevalence may underestimate the true population exposure as a result of waning antibodies among individuals who were infected early in the first wave.

The seroprevalence and protective effect of sars-cov-2 antibodies in scottish healthcare workers

RATIONALE: Healthcare workers (HCW) are believed to be at increased risk of SARS-CoV-2 infection. The extent of that increased risk compared to the general population and the groups most at risk have not been extensively studied. It is also not known to what extent the natural production of antibodies to SARS-CoV-2 is protective against re-infection. Methods: A prospective observational study of health and social care workers in NHS Tayside (Scotland, UK) from May to September 2020. The Siemens SARS-CoV-2 total antibody assay was used to establish seroprevalence in this cohort. Patients provided clinical information including demographics and workplace. Controls, matched for age and sex to the general Tayside population, were studied for comparison. New laboratory confirmed infections post September 2020 were recorded to determine if the presence of SARS-CoV-2 antibodies protect against re-infection. Results: A total of 2063 health and social care workers were recruited for this study. The participants were predominantly female (81.7%) and 95.5% were white. 300 healthcare workers had a positive antibody test (14.5%). 11 out of 231 control sera tested positive (4.8%). Healthcare workers therefore had an increased likelihood of a positive test (Odds ratio 3.4 95% CI 1.85-6.16, p<0.0001). Dentists, healthcare assistants and porters were the job roles most likely to test positive. Those working in front-line roles with COVID-19 patients were more likely to test positive (17.4% vs. 13.4%, p=0.02). 97.3% of patients who had previously tested positive for SARSCoV-2 by RT-PCR had positive antibodies, compared to 10.9% of individuals with a symptomatic illness who had tested negative. 18.7% of HCW had an asymptomatic infection. Anosmia was the symptom most associated with the presence of detectable antibodies. There were 38 new infections with SARS-CoV-2 in HCW who were previously antibody negative and 1 symptomatic RT-PCR positive re-infection in a HCW who had detectable antibodies 76 days prior to re-infection. The presence of antibodies was 85% protective against re-infection with SARS-CoV-2 (HR 0.15, 95% CI 0.06 to 0.35, p=0.03). Conclusion: In this study, healthcare workers were three times more likely to test positive for SARS-CoV-2 than the general population. Almost all of the infected individuals developed an antibody response and this was 85% effective in protecting against reinfection with SARS-CoV-2.