SARS-CoV-2 seroprevalence among vaccinated nursing home residents and staff in Belgium in August 2021

The SCOPE study assesses the prevalence of anti-SARS-CoV-2 antibodies among a representative sample of residents and staff in Belgian NH (nursing homes). Starting from February 1st 2021, a cohort of 1,640 residents and 1.368 staff members in 69 Belgian NHs are being tested every two months on the presence of anti-SARS-CoV-2 antibodies. This brief communication reports on the prevalence of anti-SARS-CoV-2 antibodies among vaccinated nursing home residents and staff. At the end of April 2021, the large scale vaccination campaign in Belgian nursing homes, which took place between January 5th and March 24th 2021, resulted in a vaccination coverage of 97% in NH residents and 84% in staff members. For these vaccinated groups, we describe the prevalence of anti-SARS-CoV-2 antibodies immediately following the vaccination campaign (April, 2021) and the seroprevalence evolution over the two following testing periods (in June and August 2021). Data collection of the August 2021 testing period was not finished at the time of compiling this brief communication. The August 2021 testing period comprises the data from 65 out of the 69 nursing homes. Additionally, some antibody test results are expected the coming weeks in case of self-sampling (for staff in particular). Results given here are preliminary. Small adaptations in some data might occur in future reports.SCOP

Vaccine hesitancy for the COVID-19 vaccine booster dose among nursing home staff fully vaccinated with the primary vaccination course in Belgium.

peer reviewedIn Belgium, nursing home (NH) staff (NHS) and residents were prioritised for the initial COVID-19 vaccination and successive booster doses. The vaccination campaign for the first booster started in September 2021 in Belgian NH. Our first study about vaccine hesitancy towards the COVID-19 vaccine in Belgian NHS already showed a degree of fear for the primary vaccination course (T1). This new study aims to evaluate vaccine hesitancy to get the first booster (T2) in a population of fully vaccinated (with two doses) NHS. A random stratified sample of NHS who received the primary vaccination course (N = 954) completed an online questionnaire on COVID-19 booster hesitancy (between 25/11/2021 and 22/01/2022). NHS who hesitated or refused the booster were asked for the main reason for their hesitation/refusal. Overall, 21.0 % of our population hesitated before, were still hesitating or refused the booster, NHS that were not hesitant at T1 being 5.7 times less likely to hesitate to get the first booster dose (Adjusted OR 0.179, 95 % CI: 0.120, 0.267). Although there was a slight reduction (23.5 % to 20.1 %) in the proportion of NHS who hesitated/refused vaccination at T1 compared to T2 (p = 0.034), the fear of unknown effects was the principal reason for hesitation/refusal, already mentioned in our first study. NHS were not reassured concerning their initial fears. Given the likelihood that booster vaccinations will be necessary over the coming years, a communication strategy specific to NHS should be implemented.CHARMIN

Prevalence of SARS-CoV-2 antibodies among Belgian nursing home residents and staff during the primary COVID-19 vaccination campaign.

peer reviewed[en] BACKGROUND: Nursing home residents (NHR) and staff have been disproportionally affected by the COVID-19 pandemic and were therefore prioritised in the COVID-19 vaccination strategy. However, frail older adults, like NHR, are known to have decreased antibody responses upon vaccination targeting other viral antigens. OBJECTIVES: As real-world data on vaccine responsiveness, we assessed the prevalence of SARS-CoV-2 antibodies among Belgian NHR and staff during the primary COVID-19 vaccination campaign. METHODS: In total, we tested 1629 NHR and 1356 staff across 69 Belgian NHs for the presence of SARS-CoV-2 IgM/IgG antibodies using rapid tests. We collected socio-demographic and COVID-19-related medical data through questionnaires. Sampling occurred between 1 February and 24 March 2021, in a randomly sampled population that received none, one or two BNT162b2 vaccine doses. RESULTS: We found that during the primary vaccination campaign with 59% of the study population fully vaccinated, 74% had SARS-CoV-2 antibodies. Among fully vaccinated individuals only, fewer residents tested positive for SARS-CoV-2 antibodies (77%) than staff (98%), suggesting an impaired vaccine-induced antibody response in the elderly, with lowest seroprevalences observed among infection naïve residents. COVID-19 vaccination status and previous SARS-CoV-2 infection were predictors for SARS-CoV-2 seropositivity. Alternatively, age ≥ 80 years old, the presence of comorbidities and high care dependency predicted SARS-CoV-2 seronegativity in NHR. CONCLUSION: These findings highlight the need for further monitoring of SARS-CoV-2 immunity upon vaccination in the elderly population, as their impaired humoral responses could imply insufficient protection against COVID-19. TRIAL REGISTRATION: This study was retrospectively registered on ClinicalTrials.gov (NCT04738695)

Shared genetic risk between eating disorder- and substance-use-related phenotypes:Evidence from genome-wide association studies

First published: 16 February 202

Exploratory study of risk factors related to SARS-CoV-2 prevalence in nursing homes in Flanders (Belgium) during the first wave of the COVID-19 pandemic.

In a previous study in Belgian nursing homes (NH) during the first wave of the COVID-19 pandemic, we found a SARS-CoV-2 seroprevalence of 17% with a large variability (0-45%) between NH. The current exploratory study aimed to identify nursing home-specific risk factors for high SARS-CoV-2 seroprevalence. Between October 19th, 2020 and November 13th, 2020, during the second COVID-19 wave in Belgium, capillary blood was collected on dried blood spots from 60 residents and staff in each of the 20 participating NH in Flanders and Brussels. The presence of SARS-CoV-2-specific IgG antibodies was assessed by ELISA. Risk factors were evaluated using a questionnaire, filled in by the director or manager of the NH. Assessed risk factors comprised community-related factors, resident-related factors, management and performance features as well as building-related aspects. The relation between risk factors and seroprevalence was assessed by applying random forest modelling, generalized linear models and Bayesian linear regression. The present analyses showed that the prevalence of residents with dementia, the scarcity of personal protective equipment (surgical masks, FFP2 masks, glasses and face shields), and inadequate PCR test capacity were related to a higher seroprevalence. Generally, our study put forward that the various aspects of infection prevention in NH require more attention and investment. This exploratory study suggests that the ratio of residents with dementia, the availability of test capacity and personal protective equipment may have played a role in the SARS-CoV-2 seroprevalence of NH, after the first wave. It underscores the importance of the availability of PPE and education in infection prevention. Moreover, investments may also yield benefits in the prevention of other respiratory infections (such as influenza)

Evaluation of a smartphone‐operated point‐of‐care device using loop‐mediated isothermal amplification technology for rapid and remote detection of SARS‐CoV‐2

During the SARS‐CoV‐2 pandemic, rapid and sensitive detection of SARS‐CoV‐2 has been of high importance for outbreak control. Reverse transcriptase polymerase chain reaction (RT‐PCR) is the current gold standard, however, the procedures require an equipped laboratory setting and personnel, which have been regularly overburdened during the pandemic. This often resulted in long waiting times for patients. In contrast, reverse transcriptase loop‐mediated isothermal amplification (RT‐LAMP) is a simple, cost‐efficient, and fast procedure, allowing for rapid and remote detection of SARS‐CoV‐2. In the current study, we performed a clinical evaluation of a new point‐of‐care test system based on LAMP‐technology for SARS‐CoV‐2 detection, providing a result within 25 min (1copy™ COVID‐19 MDx Kit Professional system). We tested 112 paired nasopharyngeal swabs, collected in the COVID‐19 Ghent University Hospital test center, using the 1copy™ COVID‐19 MDx Kit Professional system, and RT‐PCR as the reference method. The test system was found to have a clinical sensitivity of 93.24% (69/74) (95% confidence interval [CI]: 84.93%–97.77%) and specificity of 97.37% (37/38) (95% CI: 86.19%–99.93%). Due to its easy smartphone operation and ready‐to‐use reagents, it ought to be easily applied in for instance general practices, pharmacies, nursing homes, schools, and companies. This would facilitate an efficient SARS‐CoV‐2 outbreak control and quarantine policy, as diagnosis can occur sooner in a near‐patient setting

Nursing home specific questionnaire.

In a previous study in Belgian nursing homes (NH) during the first wave of the COVID-19 pandemic, we found a SARS-CoV-2 seroprevalence of 17% with a large variability (0–45%) between NH. The current exploratory study aimed to identify nursing home-specific risk factors for high SARS-CoV-2 seroprevalence. Between October 19th, 2020 and November 13th, 2020, during the second COVID-19 wave in Belgium, capillary blood was collected on dried blood spots from 60 residents and staff in each of the 20 participating NH in Flanders and Brussels. The presence of SARS-CoV-2-specific IgG antibodies was assessed by ELISA. Risk factors were evaluated using a questionnaire, filled in by the director or manager of the NH. Assessed risk factors comprised community-related factors, resident-related factors, management and performance features as well as building-related aspects. The relation between risk factors and seroprevalence was assessed by applying random forest modelling, generalized linear models and Bayesian linear regression. The present analyses showed that the prevalence of residents with dementia, the scarcity of personal protective equipment (surgical masks, FFP2 masks, glasses and face shields), and inadequate PCR test capacity were related to a higher seroprevalence. Generally, our study put forward that the various aspects of infection prevention in NH require more attention and investment. This exploratory study suggests that the ratio of residents with dementia, the availability of test capacity and personal protective equipment may have played a role in the SARS-CoV-2 seroprevalence of NH, after the first wave. It underscores the importance of the availability of PPE and education in infection prevention. Moreover, investments may also yield benefits in the prevention of other respiratory infections (such as influenza).</div

Graphical presentation of the random forest modeling showing the relative importance of the risk factors in relation to seroprevalence (using %MSE).

Graphical presentation of the random forest modeling showing the relative importance of the risk factors in relation to seroprevalence (using %MSE).</p

Continuous risk factors in the twenty included nursing homes (NH).

Continuous risk factors in the twenty included nursing homes (NH).</p

Categorical risk factors in the twenty included nursing homes (NH).

Categorical risk factors in the twenty included nursing homes (NH).</p