Unexpected detection of SARS-CoV-2 antibodies in the prepandemic period in Italy

The study “Unexpected detection of SARS-CoV-2 antibodies in the prepandemic period in Italy” by Apolone et al., published in the Tumori Journal in 2021, presents significant findings regarding the early circulation of the SARS-CoV-2 virus in Italy, potentially reshaping the understanding of the onset of the COVID-19 pandemic.

The key points of the study are:

  1. Study Objective and Methodology: The study aimed to investigate the presence of SARS-CoV-2 specific antibodies in blood samples collected from 959 asymptomatic individuals as part of a lung cancer screening trial in Italy. The time frame for sample collection was between September 2019 and March 2020. The researchers used an enzyme-linked immunosorbent assay (ELISA) to detect receptor-binding domain (RBD)–specific antibodies.
  2. Main Findings:
    • The study detected SARS-CoV-2 RBD-specific antibodies in 111 out of the 959 (11.6%) individuals.
    • These antibodies were found as early as September 2019, several months before the first reported COVID-19 case in Italy.
    • A significant number of these cases (53.2%) were from Lombardy, the region which later became the epicenter of the Italian COVID-19 outbreak.
    • Two peaks in antibody positivity were observed: one starting in late September 2019 and another in February 2020.
  3. Geographical and Temporal Distribution:
    • The first positive samples were recorded in September 2019 in various Italian regions.
    • The geographic distribution and timing of these early cases closely mirrored the later officially registered COVID-19 cases in Italy.
  4. Neutralizing Antibodies Analysis:
    • The study also involved a qualitative microneutralization assay to detect functional neutralizing antibodies (NAbs). Six out of the 111 positive individuals showed presence of NAbs, some as early as October 2019.
    • This supports the hypothesis of the virus circulating unnoticed in Italy well before the identification of the first official case in February 2020.
  5. Broader Implications:
    • These findings suggest that the virus was circulating in Italy and potentially other countries before the first cases were officially identified and reported.
    • The study challenges the initially understood timeline of the COVID-19 pandemic’s spread, indicating an earlier onset.
  6. Limitations and Further Research: The study emphasizes the need for more comprehensive research to understand the initial history and epidemiology of COVID-19. Further investigations could refine the screening strategies and contribute to better containment measures for potential future outbreaks.

In conclusion, the study by Apolone et al. provides crucial insights into the early presence and spread of the SARS-CoV-2 virus in Italy, indicating that the virus was circulating earlier than previously thought. This challenges the conventional understanding of the pandemic’s timeline and has significant implications for our understanding of the virus’s early spread and containment strategies.

Read More: https://journals.sagepub.com/doi/epub/10.1177/0300891620974755

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