给1200多万接种了疫苗的美国人带来了安心的消息强生公司据该公司称，一项新的研究表明，单次注射疫苗可能会对delta变异体提供良好的保护。

这种高度可传播的三角洲变异体现在预计将成为美国的优势菌株。

这些发现是初步的，但很有希望。在一项实验室实验中，研究人员分析了10名接种过一次性强生疫苗的人的血液，并对其进行了多种相关变异体的测试，包括德尔塔。

他们发现，这种疫苗似乎可以对抗新的变异体，这可以通过所谓的“中和抗体滴度”和免疫系统反应的其他指标来说明。

强生公司执行委员会副主席兼首席科学官保罗·斯托菲尔斯博士在一份声明中说:“今天新宣布的研究加强了强生新冠肺炎疫苗在全球范围内帮助保护人们健康的能力。”。

先前的数据表明疫苗包括辉瑞公司和莫德纳公司生产的产品，很可能会抵制delta变体。但是一些专家担心强生疫苗，不像其他疫苗，只包括一剂，可能不会有好结果。

贝丝以色列女执事医疗中心病毒学和疫苗研究中心主任丹·巴鲁赫博士在接受美国广播公司采访时表示:“我认为这让人放心。”。"我们发现J&J疫苗能诱导中和抗体."

事实上，巴鲁赫说，这项研究的另一个令人放心的发现是，接种强生疫苗的人在八个月后似乎有很强的免疫系统反应。

马特·洛克/美联社

文件——在这张2021年3月26日的文件照片中，费城消防局的一名成员正在准备.

“我们看到了令人惊讶的良好反应持久性，”巴鲁赫说。“我们对这些人进行了八个月的跟踪，在八个月的时间里，抗体和T细胞反应非常稳定。”

越来越多的证据表明，新冠肺炎疫苗可能提供比一些科学家最初预期的更持久的保护。这是因为免疫系统的其他部分，称为记忆B细胞的细胞，随着时间的推移继续成熟，并保持其抵抗感染的能力。

巴鲁赫警告说，这项研究存在局限性，它为研究人员提供了来自实验室实验的有用线索，而不是来自成千上万人的真实证据。

“我们的发现表明，一针J&J疫苗可以提高针对δ变异体的中和抗体水平。我们的研究没有显示临床保护，”他说。

但是对于那些接种了强生单次疫苗的人来说，这项研究是一个令人放心的迹象，表明这种疫苗对达美变异体的效果可能与对其他循环变异体的效果一样好。

Johnson & Johnson vaccine seems to stand up against delta variant, preliminary research suggests

In reassuring news for the more than 12 million Americans vaccinated withJohnson & Johnson, a new study indicates the single-shot vaccine will likely offer good protection against the delta variant, according to the company.

The highly transmissible delta variant is now predicted to become the dominant strain in the United States.

The findings are preliminary but promising. In a laboratory experiment, researchers analyzed the blood of 10 people who had been vaccinated with the single-shot Johnson & Johnson vaccine, and tested it against multiple concerning variants, including delta.

They found that the vaccine appeared to work against new variants, as indicated by so-called "neutralizing antibody titers" and other indications of immune system response.

"Today's newly announced studies reinforce the ability of the Johnson & Johnson COVID-19 vaccine to help protect the health of people globally," Dr. Paul Stoffels, vice chairman of the executive committee and chief scientific officer at Johnson & Johnson, said in a statement.

Prior data has indicated that othervaccines, including those made by Pfizer and Moderna, are likely to hold up against thedelta variant. But some experts worried the Johnson & Johnson vaccine, which unlike the others, only includes one dose, might not fare as well.

"I would say it's reassuring," Dr. Dan Barouch, director of the Center for Virology and Vaccine Research at Beth Israel Deaconess Medical Center, who helped lead the research, told ABC News. "We found the J&J vaccine induces neutralizing antibodies."

In fact, Barouch said another reassuring finding of the study was that people vaccinated with the Johnson & Johnson shot appeared to have a strong immune system response up to eight months later.

"We saw surprisingly good durability of responses," Barouch said. "We followed these individuals for eight months, and over eight months, the antibody and T cell responses were very stable."

A growing body of evidence suggests that COVID-19 vaccines may offer longer-lasting protection than some scientists initially anticipated. That's because other parts of the immune system, cells called memory B cells, continue to mature over time, and retain their ability to fight infection.

Barouch cautioned there are limitations to this research, which offers researchers helpful clues from laboratory experiments rather than real-world evidence from thousands of people.

"Our findings show that a single shot of the J&J vaccine raises robust neutralizing antibody levels against the delta variant. Our study does not show clinical protection," he said.

But for those who were vaccinated with the single-shot Johnson & Johnson vaccine, this study is a reassuring indication that the vaccine is likely to work just as well against the delta variant as it does for other circulating variants.