Vaccination offers long-lasting protection from the worst outcomes of COVID-19, according to a new study by the University of North Carolina at 教堂山分校.
The emergence of the delta and omicron variants has raised questions about whether breakthrough infections are caused by waning immunity or by the more transmissible variants.
Results of the study published in the New England Journal of 医学 suggest that declining immunity is responsible for breakthrough infections, but vaccines maintained protection from hospitalization and severe disease nine months after getting the first shot.
“The primary takeaway message from our study is that unvaccinated people should get vaccinated right away,该研究的主要作者说 Danyu林, Dennis Gillings生物统计学特聘教授 北卡罗来纳大学吉林全球公共卫生学院. “The results of our study also underscore the importance of booster shots, 特别是对老年人来说.”
这项研究, which is a collaboration between the UNC-教堂山分校 and the North Carolina Department of 健康 and Human Services, examined data on COVID-19 vaccination history and health outcomes for 10.6 million North Carolina residents between December 2020 and September 2021.
这项研究 results were used by the Centers for Disease Control and Prevention to 支持使用加强针.
“This is an excellent example of the wonderful re足球外围官网登录 partnership between the Gillings School and NCDHHS, who are working together to generate the evidence base needed to keep our communities safe,潘妮·戈登·拉森说, Carla Smith Chamblee Distinguished Professor of 全球 Nutrition and associate dean for re足球外围官网登录 at 北卡罗来纳大学吉林全球公共卫生学院
This data included outcomes from COVID-19 cases caused by the delta variant. However, data from this study were collected before the discovery of the omicron variant.
“通过对丰富的监测数据应用一种新颖的方法, we were able to provide precise and comprehensive characterization of the effectiveness over a nine-month period for the three vaccines employed in the U.S.林说:“.
“与以前的研究, we estimated the vaccine effectiveness in reducing the current risks of COVID-19, hospitalization and death as a function of time elapsed since the first dose,”林继续说. “This information is critically important in determining the need for and the optimal timing of booster vaccination.”
这项研究 found that effectiveness of the Pfizer and Moderna mRNA vaccines in reducing the risk of COVID-19 reached a peak of about 95% at two months after the first dose and then gradually declined. 在七个月, 辉瑞公司的疫苗的有效性下降到67%, 与Moderna疫苗相比, 保持了80%的有效性.
在两种mRNA疫苗的早期接受者中, 从6月中旬到7月中旬，效率急剧下降, 当德尔塔型飞机起降时.
约翰逊的有效性 & Johnson adenovirus vaccine was 75% at one month after injection and fell to 60% after five months.
All three vaccines were effective at keeping people out of the hospital due to severe COVID-19. Effectiveness of the Pfizer vaccine reached a peak of 96% at two months and remained around 90% at seven months; effectiveness of the Moderna vaccine reached a peak of 97% at two months and remained at 94% at seven months. 约翰逊的有效性 & Johnson vaccine reached a peak of 86% at two months and was higher than 80% through six months.
For all three vaccines, effectiveness against death was higher than that of hospitalization.
“因为美国的大多数疫苗.S. were administered more than seven months ago and only a small percentage of the population has received boosters, waning immunity is likely contributing to the breakthrough infections with the omicron variant林说:“.
5岁及以上的所有人都有资格接种COVID-19疫苗. 18岁及以上的人应加强注射疫苗. 访问NC DHHS网站，找到附近的疫苗接种诊所.
这项研究是由林领导的，主要贡献来自于谷, 生物统计学博士研究生 Donglin曾庆红, 生物统计学教授. NCDHHS流行病学家布拉德福德·惠勒, 海莉年轻, 个女孩儿汗阳光明媚, 和扎克·摩尔参与了这项研究. Shannon Holloway from the North Carolina State Department of Statistics also contributed.