Center for Cervical Cancer Elimination, Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden.
Tampere University Hospital, Tampere, Finland.
PLoS One. 2024 Jul 11;19(7):e0305285. doi: 10.1371/journal.pone.0305285. eCollection 2024.
Serological surveys of the prevalence of SARS-CoV-2 are instrumental to understanding the course of the COVID-19 epidemic. We evaluate the seroprevalence of SARS-CoV-2 among young adult Finnish females residing in 25 communities all over Finland from 2020 until 2022.
Between 1st March 2020 and 30th June 2022, 3589 blood samples were collected from 3583 women born in 1992-95 when aged 25 or 28 years old attending the follow-up of an ongoing population-based trial of cervical screening strategies. The crude and population standardized SARS-CoV-2 seroprevalence was measured using nucleocapsid (induced by infection) and spike wild-type (WT) protein (induced both by infection and by vaccination) antigens over time and stratified by place of residence (inside or outside the Helsinki metropolitan region).
During 2020 (before vaccinations), spike-WT and nucleocapsid IgG antibodies followed each other closely, at very low levels (<5%). Spike-WT seropositivity increased rapidly concomitant with mass vaccinations in 2021 and reached 96.3% in the 2nd quartile of 2022. Antibodies to nucleocapsid IgG remained relatively infrequent throughput 2020-2021, increasing rapidly in the 1st and 2nd quartiles of 2022 (to 19.7% and 56.6% respectively). The nucleocapsid IgG seropositivity increased more profoundly in participants residing in the Helsinki metropolitan region (4.5%, 8.4% and 43.9% in 2020, 2021 and 2022 respectively) compared to those residing in communities outside the capital region (4.5%, 4.3% and 34.7%).
Low SARS-CoV-2 infection-related seroprevalence during 2020-2021 suggest a comparatively successful infection control. Antibodies to the SARS-CoV-2 WT spike protein became extremely common among young women by the end of 2021, in line with the high uptake of SARS-CoV-2 vaccination. Finally, the rapid increase of seroprevalences to the SARS-CoV-2 nucleocapsid protein during the first and second quartile of 2022, imply a high incidence of infections with SARS-CoV-2 variants able to escape vaccine-induced protection.
血清学调查 SARS-CoV-2 的流行率对于了解 COVID-19 疫情的进程至关重要。我们评估了 2020 年至 2022 年间居住在芬兰各地 25 个社区的年轻成年芬兰女性中 SARS-CoV-2 的血清流行率。
2020 年 3 月 1 日至 2022 年 6 月 30 日，从参加正在进行的宫颈癌筛查策略人群试验随访的 3583 名出生于 1992-95 年的女性中采集了 3589 份血液样本，当时她们年龄为 25 或 28 岁。使用核衣壳（由感染引起）和刺突野生型（WT）蛋白（由感染和疫苗接种引起）抗原随时间测量未校正和人口标准化的 SARS-CoV-2 血清流行率，并按居住地（赫尔辛基大都市区内外）分层。
2020 年（疫苗接种前），刺突-WT 和核衣壳 IgG 抗体水平非常低（<5%），彼此密切相关。2021 年大规模疫苗接种后，刺突-WT 血清阳性率迅速上升，2022 年第二季度达到 96.3%。核衣壳 IgG 抗体在 2020-2021 年期间一直相对罕见，2022 年第一和第二季度迅速增加（分别为 19.7%和 56.6%）。居住在赫尔辛基大都市区的参与者的核衣壳 IgG 血清阳性率增加更为显著（2020 年为 4.5%、2021 年为 8.4%、2022 年为 43.9%），而居住在大都市区以外社区的参与者的核衣壳 IgG 血清阳性率分别为 4.5%、4.3%和 34.7%。
2020-2021 年期间 SARS-CoV-2 感染相关血清流行率较低表明感染控制相对成功。到 2021 年底，年轻女性中 SARS-CoV-2 WT 刺突蛋白抗体变得非常普遍，这与 SARS-CoV-2 疫苗接种率高有关。最后，2022 年第一和第二季度核衣壳蛋白血清流行率的迅速上升表明，能够逃避疫苗诱导保护的 SARS-CoV-2 变异体的感染发生率很高。
