Vaccines (May 2021)

Repeated Leftover Serosurvey of SARS-CoV-2 IgG Antibodies in Greece, May to August 2020

  • Zacharoula Bogogiannidou,
  • Matthaios Speletas,
  • Alexandros Vontas,
  • Dimitrios J. Nikoulis,
  • Katerina Dadouli,
  • Maria A. Kyritsi,
  • Varvara A. Mouchtouri,
  • Paraskevi Mina,
  • Lemonia Anagnostopoulos,
  • Michalis Koureas,
  • Vasileios Karavasilis,
  • Olga Nikou,
  • Ourania Pinaka,
  • Pavlos C. Thomaidis,
  • Kornilia Kadoglou,
  • Konstantinos Bedevis,
  • Natalia Spyrou,
  • Alexandros A. Eleftheriou,
  • Vassiliki Papaevangelou,
  • Achilleas Gikas,
  • Alkiviadis Vatopoulos,
  • Evangelia E. Ntzani,
  • Panagiotis Prezerakos,
  • Sotirios Tsiodras,
  • Christos Hadjichristodoulou

DOI
https://doi.org/10.3390/vaccines9050504
Journal volume & issue
Vol. 9, no. 5
p. 504

Abstract

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A serosurvey of IgG antibodies against SARS-CoV-2 was conducted in Greece between May and August 2020. It was designed as a cross-sectional survey and was repeated at monthly intervals. The leftover sampling methodology was used and a geographically stratified sampling plan was applied. Of 20,110 serum samples collected, 89 (0.44%) were found to be positive for anti-SARS-CoV-2 antibodies, with higher seroprevalence (0.35%) observed in May 2020. The highest seroprevalence was primarily observed in the “30–49” year age group. Females presented higher seroprevalence compared to males in May 2020 (females: 0.58% VS males: 0.10%). This difference reversed during the study period and males presented a higher proportion in August 2020 (females: 0.12% VS males: 0.58%). Differences in the rate of seropositivity between urban areas and the rest of the country were also observed during the study period. The four-month infection fatality rate (IFR) was estimated to be 0.47%, while the respective case fatality rate (CFR) was at 1.89%. Our findings confirm low seroprevalence of COVID-19 in Greece during the study period. The young adults are presented as the most affected age group. The loss of the cumulative effect of seropositivity in a proportion of previous SARS-CoV-2 infections was indicated.

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