在临床试验中，辉瑞和莫德纳新冠肺炎疫苗严重不良事件发生率低。现在，美国疫苗接种第一个月的真实数据证实了这一数据。
疾病预防控制中心的一份新报告着眼于VAERS的数据，这是一个由政府监控的疫苗安全门户网站，要求美国卫生保健人员报告接种后的不良事件。
在一个月内注射了近1400万剂疫苗的情况下，仅向VAERS发送了约7000份报告——其中91%描述了轻度事件，如头痛、疲劳和头晕。
过敏反应是一种获得广泛媒体报道的疫苗反应，被发现并不常见:共报告了62例病例，发生率为百万分之4.5，与其他常见疫苗的过敏反应发生率相当。
在1400万剂量中，VAERS报告了113例死亡；78例来自长期护理机构，35例来自机构外——迄今为止，这些死亡病例中没有一例与疫苗直接相关。
范德比尔特大学医学中心预防医学和传染病教授威廉·沙夫纳博士说，这些数据并不完全令人惊讶。
“安全性评估的全面性比我们在美国使用的任何许可疫苗都要好，”他告诉美国广播公司新闻。“两种疫苗的临床试验都非常广泛，而且都显示出非常低的严重不良反应率。”
疾控中心还从v-safe收集了患者报告的数据，v-safe是一款用于自愿报告不良事件的智能手机应用程序。在参与的160万名疫苗接种者中，大多数报告了轻度副作用，如注射部位疼痛、疲劳、头痛和寒战。据报道，这些症状在注射后的第一天最明显，第二次注射后更严重，但在随后的每一天都有所改善，在第3或第4天消失。
该应用程序还收集了怀孕状况的数据，并将在专门的登记处跟踪近11000名报告怀孕的女性。
疾控中心的数据有限，因为它严重依赖自报数据。例如，在VAERS和v-safe报告中，大多数不良事件都发生在妇女身上。但是正如沙夫纳所描述的，这并不一定意味着女性更容易做出反应。
“我更倾向于认为这是一种报道偏见，”他说，并描述了男女之间有据可查的医疗保健利用差异。"女性更倾向于寻求医疗保健，更倾向于报告疾病。"
沙夫纳说，那些认为疫苗推出速度过于仓促的人可以放心，疾病预防控制中心的报告。
“现在我们有了经过很好分析的数据，来自一系列非常全面的监控系统，我们可以超越非常大的研究，说，看，我们正在现实世界中这样做，在你的朋友和邻居中，”他说。“这种疫苗仍然非常非常安全。”
Serious COVID-19 vaccine reactions are rare, says new CDC report
In clinical trials, the Pfizer and Moderna COVID-19 vaccines demonstrated low rates of serious adverse events. Now, real-world data from the first month of vaccine administration in the U.S. corroborates that data.
A new report from the CDC looks at numbers from VAERS, a government-monitored vaccine safety portal where health care workers in the U.S. are required to report adverse events after vaccinations.
In a month where nearly 14 million vaccine doses were administered, only about 7,000 reports were sent to VAERS – 91% of which described mild events, such as headache, fatigue and dizziness.
Anaphylaxis, a vaccine reaction that garnered wide media coverage, was found to be uncommon: 62 total cases were reported, at a rate of 4.5 per million doses – comparable to the rate of anaphylaxis with other common vaccines.
Amid the 14 million doses, 113 deaths were reported to VAERS; 78 from long-term care facilities and 35 outside of facilities – and so far, none of those deaths have been directly linked to the vaccine.
The data is not entirely surprising, says William Schaffner, M.D., a professor of preventive medicine and infectious disease at Vanderbilt University Medical Center.
"The comprehensiveness of the safety evaluation has been better than we've done for any licensed vaccine that we've used in the United States," he told ABC News. "The clinical trials of both vaccines were very extensive, and both of them showed very low rates of serious adverse reactions."
The CDC also collected patient-reported data from v-safe, a smartphone app for reporting adverse events voluntarily. Of the 1.6 million vaccine recipients who participated, the majority reported mild side effects such as injection site pain, fatigue, headache and chills. These symptoms were reported to be most prominent in the first day after injection – and worse with the second dose – but improved on every subsequent day, disappearing by day 3 or 4.
The app also collected data on pregnancy status, and the nearly 11,000 women who reported to be pregnant will be followed in a dedicated registry.
The CDC's data is limited, as it relies heavily on self-reported data. For example, in both the VAERS and v-safe reports, most adverse events were noted in women. But as Schaffner describes, this does not necessarily mean that women are more prone to reactions.
"I'm more inclined to believe that it's a reporting bias," he said, describing the well-documented difference in health care utilization between men and women. "Women are more inclined to seek medical care and more inclined to report illness."
Those who judged the pace of the vaccine rollout as too hasty can rest assured by the CDC's reporting, says Schaffner.
"Now that we have data that is very well analyzed, from a really comprehensive series of surveillance systems, we can go beyond the very large studies and say, look, we're doing this in the real world, among your friends and neighbors," he said. "This vaccine continues to be very, very safe."
