Medical Data Center, Ningbo City First Hospital, Ningbo, Zhejiang Province, China.
Department of General Internal Medicine, Ningbo City First Hospital, Ningbo, Zhejiang Province, China.
Environ Res. 2022 Dec;215(Pt 1):114229. doi: 10.1016/j.envres.2022.114229. Epub 2022 Aug 30.
We aimed to determine the influence of vaccination and air temperature on COVID-19 transmission and severity.
The study data in 146 countries from January 6, 2020 to July 28, 2022 were aggregated into 19,856 weeks. Country-level weekly incidence, time-varying reproduction number (Rt), mortality, and infection-fatality ratio (IFR) were compared among groups of these weeks with different vaccination rates and air temperatures.
Weeks with <15 °C air temperature and 60% vaccination showed the highest incidence (mean, 604; SD, 855; 95% CI, 553-656, unit, /100,000 persons; N = 1073) and the highest rate of weeks with >1 Rt (mean, 41.6%; SD, 1.49%; 95% CI, 39.2-45.2%; N = 1090), while weeks with >25 °C and <20% showed the lowest incidence (mean, 24; SD, 75; 95% CI, 22-26; N = 5805) and the lowest rate of weeks with >1 Rt (mean, 15.3%; SD, 0.461%; 95% CI, 14.2-16.2%; N = 6122). Mortality in weeks with <15 °C (mean, 2.1; SD, 2.8; 95% CI, 2.0-2.2, unit, /100,000 persons; N = 4365) was five times of the mortality in weeks with >25 °C (mean, 0.44; SD, 1; 95% CI, 0.41-0.46; N = 7741). IFR ranged between 2% and 2.6% (SD, 1.9%-2.4%; 95% CI, 2.0-2.7%) at < 20% vaccination level, 1.8% (SD, 2%-2.2%; 95% CI, 1.7-2.0%) at 20-60% vaccination level, and 0.7%-1% (SD, 1%-1.8%; 95% CI, 0.7-1.1%) at > 60% vaccination level and at all air temperatures (all P < 0.001).
Vaccination was insufficient to mitigate the transmission since the significantly elevated weekly incidence and >1 Rt rate in weeks with high vaccination, while IFR was reduced by high vaccination. Countries with long-term low air temperature were affected by high transmission and high mortality.
本研究旨在探讨疫苗接种和气温对新冠病毒传播和严重程度的影响。
本研究数据来源于 2020 年 1 月 6 日至 2022 年 7 月 28 日期间的 146 个国家，共分为 19856 周。通过比较不同疫苗接种率和气温组别的国家每周发病率、时变繁殖数（Rt）、死亡率和感染病死率（IFR），评估不同因素对新冠病毒传播和严重程度的影响。
在空气温度<15°C 和疫苗接种率<60%的周次中，发病率最高（平均为 604，标准差为 855，95%置信区间为 553-656，单位为每 10 万人/周；N=1073），Rt>1 的周次比例也最高（平均为 41.6%，标准差为 1.49%，95%置信区间为 39.2-45.2%；N=1090）。而在空气温度>25°C 和疫苗接种率<20%的周次中，发病率最低（平均为 24，标准差为 75，95%置信区间为 22-26，单位为每 10 万人/周；N=5805），Rt>1 的周次比例也最低（平均为 15.3%，标准差为 0.461%，95%置信区间为 14.2-16.2%；N=6122）。在空气温度<15°C 的周次中，死亡率最高（平均为 2.1，标准差为 2.8，95%置信区间为 2.0-2.2，单位为每 10 万人/周；N=4365），是空气温度>25°C 周次的五倍（平均为 0.44，标准差为 1，95%置信区间为 0.41-0.46；N=7741）。IFR 在疫苗接种率<20%时，范围为 2%-2.6%（标准差为 1.9%-2.4%），在 20%-60%时为 1.8%（标准差为 2%-2.2%），在>60%时为 0.7%-1%（标准差为 1%-1.8%），且在所有气温条件下，IFR 均随疫苗接种率的升高而降低（均 P<0.001）。
尽管高疫苗接种率可能导致每周发病率和 Rt 率显著升高，但仍不足以完全抑制病毒传播，而 IFR 则随疫苗接种率的升高而降低。长期处于低温环境的国家可能会受到高传播率和高死亡率的影响。
