Seroprevalence of anti-SARS-CoV-2 antibodies in the Northern Italy population before the COVID-19 second wave

Abstract

Objectives: The COVID-19 pandemic is due to SARS-CoV-2 coronavirus infections. It swept across the world in the spring of 2020, and so far it has caused a huge number of hospitalizations and deaths. In the present study, the authors investigated serum anti-SARS-CoV-2 antibody prevalence in the period of June 1-September 25, 2020, in 7561 subjects in Modena, Northern Italy. Material and Methods: The study population included 5454 workers referred to testing by their companies, and 2107 residents in the Modena area who accessed testing through self-referral. Results: The authors found the overall seroprevalence to be 4.7% (95% confidence interval [CI] 4.2-5.2%), which was higher in women (5.4%, 95% CI: 4.5-6.2%) than in men (4.3%, 95% CI: 3.7-4.9%), and in the oldest age groups (7.3%, 95% CI: 5.2-9.3% for persons aged 60-69 years, and 11.8%, 95% CI: 8.6-15.1%, for persons aged ≥70 years). Among the occupational categories, the highest seroprevalence was found in healthcare workers (8.8%, 95% CI: 7.0-10.5%), dealers and vehicle repairers (5.2%, 95% CI: 2.9-7.6%), and workers in the sports sector (4.0%, 95% CI: 1.8-6.1%), while there was little or no such evidence for those employed in sectors such as transport and storage, accommodation and restaurant services, and the school system. Conclusions: These results have allowed, for the first time, to assess population seroprevalence in this area of Italy severely hit by the epidemic, while at the same time identifying the subgroups at a higher risk of exposure to SARS-CoV-2. Int J Occup Med Environ Health. 2022;35(1)

SARS-CoV-2 antibodies among people with cystic fibrosis prior to the vaccination campaign: A seroprevalence study in two specialized centres in Northern Italy

“…In addition, seroprevalence data are difficult to compare since they vary widely depending on the pandemic period when the blood samples were collected, the region where the study was conducted and the population being studied [14] . Italian data published so far were mostly collected during the first wave showing seroprevalence below 5% among the general population resident in several Italian regions, with data below 1% in most Southern regions and up to 7.5% in Lombardia [ 15 , 16 ]. A study carried out in a North Eastern Italian region including also the last quarter of 2020 (the middle of the second wave in Italy) documented a prevalence up to 16% [17] .…”

Seroprevalence Survey of Anti-SARS-CoV-2 Antibodies in a Population of Emilia-Romagna Region, Northern Italy

“…We performed a cross-sectional study investigating the prevalence of anti-SARS-CoV-2 antibodies in a population living in the central-western part of the Emilia-Romagna region in the period between 26 September 2020 and 26 March 2021. This investigation follows a previous study assessing the seroprevalence of anti-SARS-CoV-2 antibodies in subjects of the same area in the period from 1 June-25 September 2020 [17]. To do so, we collected data from the Test laboratory located in Modena province, which is one of the first accredited laboratories for serological SARS-CoV-2 testing in the Emilia-Romagna region out of the only eight locations allowed to perform such tests during the study period (Decree PG/2020/0307727 of 22 April 2020).…”

“…Considering that, some previous studies used seroprevalence data in order to better understand the distribution and the severity of SARS-CoV-2 infection [13,16]. The national average seroprevalence after the first wave was estimated to be approximately 2.5%, with the highest values and variation in Northern Italy, depending on the province of residence [13,17]. In particular, a seroprevalence study carried out in a large, highly affected area located in Northeastern Italy after the first wave reported an IgG seroprevalence of 23.1% (95% confidence interval-CI 22.0-24.1%) [14].…”

“…Following a previous study assessing the seroprevalence of anti-SARS-CoV-2 antibodies in subjects living in the central-western part of the Emilia-Romagna region before the second wave (1 June-25 September 2020) [17], in this survey, we aimed to evaluate the seroprevalence in the same area for the subsequent period with assessment and comparison of the characteristics of the study populations in order to identify potential risk factors that favored the infection development.…”

Differing kinetics of anti-spike protein IgGs and neutralizing antibodies against SARS-CoV-2 after Comirnaty (BNT162b2) immunization

“…Since the spike protein is the major SARS‐CoV‐2 surface antigen and has been shown to induce the production of neutralizing antibodies, it has been selected for COVID‐19 vaccine development (Krammer, 2020). Studies of seroprevalence of antibodies against SARS‐CoV‐2 have been conducted in different settings (Berselli et al, 2021; Cassaniti et al, 2021; Garcia‐Basteiro et al, 2020; Modenese, Mazzoli, et al, 2021; Percivalle et al, 2020; Ristić et al, 2021; Tanaka et al, 2021). In natural infection, the immune response kinetics, magnitude and relationship to COVID‐19 severity during the acute‐phase response have been defined extensively.…”