Roncati Luca, Bartolacelli Giulia, Galeazzi Carlo, Caramaschi Stefania
Department of Surgery, Medicine, Dentistry and Morphological Sciences with Interest in Transplantation, Oncology and Regenerative Medicine, University of Modena and Reggio Emilia, 41121 Modena, Italy.
Department of Maternal, Infant and Adult Medical and Surgical Sciences, University of Modena and Reggio Emilia, 41121 Modena, Italy.
Pathogens. 2023 Nov 22;12(12):1376. doi: 10.3390/pathogens12121376.
Like all RNA viruses, SARS-CoV-2 shows a high mutation rate, which has led to the emergence of new variants. Among them, Gamma and Delta developed at the turn of 2020-2021 in Amazonas and India, two ecoregions characterized by hot-humid weather, very similar to that of the summer season in Italy due to climate change, the first Western country to be hit hard by COVID-19 and to experience lockdown restrictions in a democratic framework of 58.85 million people. The aim of our research has been to evaluate the impact of climate on the COVID-19 pandemic in Italy during the summers of 2020 (before mass vaccination), 2021 (after primary mass vaccination) and 2022 (after booster mass vaccination), also taking into account the emergence of these two variants.
During the state of national health emergency and the Draghi government, the Civil Defense Department released the aggregate data coming from the Ministry of Health, the Higher Institute of Health, the Independent Provinces and the Italian Regions daily, in order to inform about the pandemic situation in Italy. Among these data there were the number of deaths, hospitalizations in intensive care units (ICU), non-ICU patients, contagions and performed swabs. By means of a team effort, we have collected and elaborated all these data, comparing the COVID-19 pandemic in Italy during the summers of 2020 (following the nationwide lockdown), 2021 and 2022.
from the summer of 2020 to the summers of 2021 and 2022 all pandemic trend indicators have shown a sharp worsening in Italy. COVID-19 deaths increased by ≈298% and ≈834%, ICU hospitalizations by ≈386% and ≈310%, non-ICU hospitalizations by ≈224% and ≈600%, contagions by ≈627% and ≈6850% (i.e., ≈68.50 times), swabs by ≈354% and ≈370%, and the mean positivity rate passed from ≈1% to ≈2% and ≈20%, respectively.
SARS-CoV-2 can be transmitted in any climate, including areas with hot and humid weather, and the emergence of variants adapted to hot-humid climates may result in summer COVID-19 outbreaks, even in neither tropical nor subtropical countries. Although COVID-19 vaccines can confer cross-protection against newly emerging variants, this cross-immunity is naturally not absolute but limited, considering that vaccine protection wanes significantly after 6 months. It follows that a subject vaccinated at the beginning of the winter will not be completely covered in the height of the summer, and we should not forget the unvaccinated. As a final remark, the long and strict nationwide lockdown made it possible to flatten SARS-CoV-2 circulation and, therefore, its negative impact on Italy during the summer of 2020.
与所有RNA病毒一样，严重急性呼吸综合征冠状病毒2（SARS-CoV-2）显示出高突变率，这导致了新变种的出现。其中，伽马变种和德尔塔变种于2020年末至2021年初在亚马孙地区和印度出现，这两个生态区域的气候炎热潮湿，由于气候变化，与意大利夏季的气候非常相似，意大利是第一个受新冠疫情重创并在拥有5885万人口的民主框架下实施封锁限制的西方国家。我们研究的目的是评估气候对意大利在2020年夏季（大规模疫苗接种前）、2021年夏季（首次大规模疫苗接种后）和2022年夏季（加强针大规模疫苗接种后）新冠疫情的影响，同时也考虑这两个变种的出现情况。
在国家卫生紧急状态和德拉吉政府执政期间，民防部门每天发布来自卫生部、高等卫生研究所、独立省份和意大利各地区的汇总数据，以便通报意大利的疫情形势。这些数据包括死亡人数、重症监护病房（ICU）住院人数、非ICU患者人数、感染人数和进行的拭子检测数量。通过团队努力，我们收集并整理了所有这些数据，比较了意大利在2020年夏季（全国封锁之后）、2021年和2022年夏季的新冠疫情情况。
从2020年夏季到2021年和2022年夏季，意大利所有疫情趋势指标均显著恶化。新冠死亡人数增加了约298%和约834%，ICU住院人数增加了约386%和约310%，非ICU住院人数增加了约224%和约600%，感染人数增加了约627%和约6850%（即约68.50倍），拭子检测数量增加了约354%和约370%，平均阳性率分别从约1%升至约2%和约20%。
SARS-CoV-2可在任何气候条件下传播，包括炎热潮湿地区，适应炎热潮湿气候的变种的出现可能导致夏季新冠疫情爆发，即使在既非热带也非亚热带的国家。尽管新冠疫苗可对新出现的变种提供交叉保护，但考虑到疫苗保护在6个月后会大幅减弱，这种交叉免疫自然不是绝对的，而是有限的。因此，在冬季初接种疫苗的人在夏季高峰期不会得到完全保护，而且我们不应忘记未接种疫苗的人群。最后需要指出的是，长期严格的全国封锁使得SARS-CoV-2的传播得以平缓，因此在2020年夏季对意大利的负面影响也得以减轻。
