伊丽莎白·罗利 Discusses Latest Data on Vaccine Effectiveness Against the Delta Variant
在2021年夏天, when the Delta variant became the predominant coronavirus strain sweeping the country, there was limited data regarding COVID-19 vaccine effectiveness to combat it. 需要更多的数据，而且要快. The Centers for Disease Control and Prevention (CDC) charged hg体育官网 with capturing, 拆包, and analyzing data supplied through the CDC-funded VISION Network of integrated care and health systems using data from a 2-month time period. The task of analyzing the data fell to hg体育官网’s 伊丽莎白·罗利, Dr.P.H.他是一名高级生物统计学家. Here she discusses her work, key findings, and the forthcoming article on those discoveries.
Q: Dr. Rowley, can you describe the process of collecting and analyzing the data?
A: 在六月和七月, when the Delta variant became predominant, our VISION Network team at hg体育官网 collected data from 30,000 patient encounters at 187 hospitals and at 221 emergency departments and urgent care clinics in multiple states. The patients presented with COVID-like illnesses and ranged in 年龄 from 18 to 75+. Their vaccination status was documented in electronic health records (EHRs) and immunization registries. All of this information was supplied by the VISION Network. The odds of COVID-19 infection were compared between those fully vaccinated and those unvaccinated using a test-negative design.
A: We found that the COVID-19 vaccines are still efficacious against the Delta variant. 然而, vaccine effectiveness against hospitalization was significantly higher among Moderna recipients (95%) compared to Pfizer recipients (80%) 和约翰逊 & 约翰逊接受者(60%). 在老年, 完全成人接种疫苗, 75岁及以上, the effectiveness was less than in younger adults (89% vs. 76%). Similar trends by vaccine type were seen in vaccine effectiveness against emergency department and urgent care visits (Moderna 92%, 辉瑞公司77%, 和约翰逊 & 约翰逊65%).
A: This was a tremendous effort by many including our hg体育官网 VISION team and our CDC colleagues. I worked with a biostatistician at CDC who designed the study, and I was able to provide input in the beginning. With help from others on the hg体育官网 team, I designed the code and built the structure of the analysis so that I could rapidly rerun the analyses every 2 weeks, while also building in flexibility to extend to further analyses by using the same chunk of code. CDC wanted us to use a functionality particular to the R statistical analysis software—a program with which I am very experienced. This work used propensity scores to estimate vaccine effectiveness and to ensure the vaccinated and unvaccinated patients were comparable.
Q: How fast was this analysis conducted?
A: 非常快. I had to analyze a new batch of data from multiple sites every 2 weeks, 数据集也在不断增长. We are answering a critical public health question. 时间压力很大.
Q: You used EHRs to support this research. What were their benefits and drawbacks?
A: EHRs are essential to rapidly gathering and harmonizing patient data across diverse populations; these data also allow for the examination of rare outcomes. One issue in working with EHR data is that not all diagnoses are necessarily recorded in the same way, and sometimes different EHR systems follow different workflows for recording medical information in the EHR. Working closely with our network partners and CDC colleagues, we were able to determine a meaningful common set of information that could be provided to the CDC in a uniform and useable format.
A: Our findings add one more important piece to the puzzle surrounding vaccine effectiveness and the Delta variant, but much more work needs to be done.
Working closely with our network partners and CDC colleagues, we were able to determine a meaningful common set of information that could be provided to the CDC in a uniform and useable format.
-伊丽莎白·罗利博士.P.H., Senior Biostatistician, 公共卫生 & 流行病学