辉瑞：研究表明辉瑞加强针将降低新冠病毒感染风险

$辉瑞(PFE)$$Moderna, Inc.(MRNA)$  

根据以色列的早期数据，当辉瑞新冠疫苗第三针加强针在7月中旬开始逐步推出，辉瑞第三针加强针在Delta病毒爆发期间为人们提供了针对新冠病毒的额外防护。

Maccabi Healthcare Services在对数据进行初步分析后发现，与接受了标准2针辉瑞疫苗的人相比，接受了加强针的人在一周至13天后的感染风险概率降低了48%至68%。保护作用随着时间的推移而提升，在第三针注射后的两周到20天，检测呈阳性的风险概率降低了70%到84%。

流行病学副教授丹尼尔·温伯格（Daniel M. Weinberger）领导的研究人员在康涅狄格州纽黑文的耶鲁大学公共卫生学院表示，此项研究于周二在同行评审和发表之前发布，评估了加强针对因Delta变异引起的感染的额外有效性保护，但不包括严重疾病。

研究结果表明，疫苗对SARS-CoV-2感染的保护力的减弱可能会在短期内因第三针而抵消。 美国、英国和其他国家目前已宣布计划进行第三针加强针的注射，以对抗传染性更强的Delta病毒变异，而此前在大流行早期接种疫苗的人的抗体水平已经下降。

研究人员说道，随着时间的推移，我们仍然需要评估更罕见且更严重的结果的影响，例如住院和死亡，且我们需要进一步监测以确定加强针的免疫力和持续时间。

以色列是全球新冠疫苗接种的领先国家之一，虽然周一报告了创纪录的每日感染人数，但这却为该国疫苗加强针的推广提供了新的动力。

原文：Pfizer Booster Shot Lowered Coronavirus Infection Risk in Study

A third shot of the Pfizer Inc.-BioNTech SE Covid vaccine provides added protection against the coronavirus during a delta outbreak, according to early data from Israel, where boosters began rolling out incrementally in mid-July.

People who received the supplemental dose had a 48% to 68% lower risk of infection a week to 13 days later, compared to those who got the standard two-dose regimen, a preliminary analysis of data from Maccabi Healthcare Services found. The protection increased with time, with a 70% to 84% reduced risk of testing positive two weeks to 20 days after getting a third shot.

The research, released Tuesday ahead of peer-review and publication, assessed the additional effectiveness of a booster shot against infection due to the delta variant, but not severe disease, according to the researchers led by Daniel M. Weinberger, an associate professor of epidemiology at the Yale School of Public Health in New Haven, Connecticut.

The findings indicate that the waning of vaccine-induced protection against SARS-CoV-2 infection may be counteracted in the short term by a third dose, the authors said. The U.S., U.K. and other countries have announced plans to administer a booster shot to counter the more-infectious delta variant as antibody levels wane in those who were vaccinated earlier in the pandemic.

“As more time elapses, it will be possible to evaluate the effects on more rare but severe outcomes, such as hospitalization and death,” the researchers said. Further monitoring is needed to determine how long immunity from the booster lasts, they added.

Israel, an early leader in Covid-19 inoculations, reported a record number of daily infections Monday, giving fresh impetus to the country’s vaccine booster drive.

文章来源：https://www.bloomberg.com/news/articles/2021-09-01/pfizer-booster-shot-lowered-coronavirus-infection-risk-in-study