马研究：科兴冠病疫苗预防重症高度有效

马研究：科兴冠病疫苗预防重症高度有效

文 / 廖慧婷

9/24/2021

马来西亚一项大型真实世界研究显示，中国科兴生物（Sinovac）研制的冠病疫苗在预防重症方面高度效性。（路透社）

（早报讯）马来西亚一项大型真实世界研究显示，中国科兴生物（Sinovac）研制的冠病疫苗在预防重症方面高度有效，而辉瑞和阿斯利康冠病疫苗的保护效率更高。

路透社报道，这项由马国政府进行的研究发现，在720万名接种了科兴疫苗者中，有0.011%的人感染冠病后须要在加护病房（ICU）接受治疗。相较之下，接种辉瑞疫苗的约650万人中，有0.002%须要住进加护病房；接种阿斯利康的74万4000多人中，则有0.001%。

与马国冠病工作小组一同进行该项研究的临床研究所所长佩里亚萨米表示，另据一项涉及126万人的研究，接种冠病疫苗（无论品牌），都能将住进加护病房的风险降低83%，染疫死亡的风险则减少了88%。

他还说，完成冠病疫苗接种的群体中，仅0.0066%染疫后须要住进加护病房。“住进加护病房的（病毒）突破率极低。”

完全接种者的死亡率也很低，仅0.01%；其中大多数人年龄在60岁以上或患有合并症。

马来西亚3200万人口中，58.7%已完成冠病疫苗接种，68.8%至少接种了第一剂。

Source

泰研究：先科兴或阿斯利康后辉瑞接种组合效果更佳

文 / 廖慧婷

9/22/2021

泰国一项研究显示，第一剂接种科兴或阿斯利康冠病疫苗，四周后接种辉瑞疫苗，该组合所产生的免疫反应效果最佳。（法新社）

（早报讯）泰国一项研究显示，第一剂接种科兴或阿斯利康冠病疫苗，四周后再接种辉瑞疫苗，该组合所产生的免疫反应效果最佳。相较之下，首剂接种科兴再打阿斯利康疫苗所产生的免疫反应较弱。

彭博社报道，上述初步研究结果，是根据泰国诗里叻研究所的一项研究得出。

泰国是首个采用“先科兴－再阿斯利康”接种组合的国家，为的是增强保护以对抗德尔塔变种病毒，并应对疫苗短缺的问题。

早前一项研究则显示，比起两剂都接种科兴疫苗，先接种科兴疫苗并在三到四周后接种阿斯利康疫苗，免疫反应可增强达八倍，促使泰国采用双品牌接种方案。

据泰国卫生部，目前该国采用的接种组合包括：科兴－阿斯利康、阿斯利康－辉瑞，以及两剂都是阿斯利康或辉瑞疫苗。

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专家：德尔塔等更强变种出现全球或永无可能实现群体免疫

来自 / 联合早报

文 / 苏玉兰

8/15/2021

本月初，美国传染病学会估计，德尔塔变种病毒已将实现群体免疫的门槛推高至80%以上，甚至可能接近90%。（法新社）

（华盛顿综合电）冠病疫情去年暴发时，各国政府希望能通过群体免疫来阻断传染；然而，德尔塔这类传染性更强的变种病毒出现后，把要达到群体免疫的门槛推高到几乎不可能跨越的水平。专家如今甚至认为，全球可能永远都无法实现群体免疫。

此前的观点是，如果有60%至70%的人口接种冠病疫苗或因染病而产生抗体，疫情就有望平息。然而，更容易传播甚至在某些情况下可避开免疫保护的新变种病毒使这个理想变成幻想。

本月初，美国传染病学会估计，德尔塔变种病毒已将实现群体免疫的门槛推高至80%以上，甚至可能接近90%。

对此，美国权威医疗机构梅奥医学中心（Mayo Clinic）的疫苗研究部门主管波伦说：“我们会实现群体免疫吗？不，非常不可能，显然是这样。”

波伦认为，即使疫苗接种率高达95%，全球也难以达到群体免疫。

“这是一场势均力敌的竞赛，比赛双方是传染性更强、可逃避免疫反应的变种病毒和冠病疫苗接种率。”

至于冠病痊愈者所产生的自然免疫力可持续多久，目前尚无定论，也不清楚自然免疫力能否有效对抗新变种病毒。

此外，未来的变种毒株或许比德尔塔更能逃避免疫，这令冠病疫情要如何、到什么时候才可能结束成了疑问。

斯坦福大学医学中心亚裔健康研究与教育中心的南亚拓展部主任马哈德万说：“如果是感染一次就可终身免疫那么简单，那就太好了，但我认为情况并非如此……这是个棘手问题。”

群体免疫是真实存在的，保护了全球大部分地区免受从麻疹到小儿麻痹症等病毒的威胁；科学家也认为它帮助根除了天花。

不过，哈佛大学陈曾熙公共卫生学院的流行病学家哈纳奇提醒：“在我看来，把焦点放在‘群体免疫’是有一定破坏性的……它反映出人们对于如何结束疫情有不切实际的愿景，也没有考虑到病毒的演变或二次感染的疾病本质。”

平息疫情最早要2022年

专家认为，全球最早要到2022年才有望平息冠病疫情。如果病毒进行另一次突变，变得传染力更强，或能更好地躲避免疫力，那么平息疫情的时间可能得再推迟。

哈纳奇认为，德尔塔病毒是无法根除的。“不过，如果有足够的免疫力，理想情况是通过接种疫苗来实现，我们可以预期冠病会成为较温和的疾病。”

梅奥医学中心的波伦指出，1918年的西班牙大流感或许可提示冠病疫情将如何发展。他认为，下来很可能出现更多种变异毒株，人们不得不接种追加剂或是定期接种针对新毒株的疫苗。

他说：“如果幸运的话，可能发生的情况是，冠病将变得更类似流感，即我们会一直与它共存。它会变得更具季节性，就像已经在传播的冠状病毒一样，我们只须继续进行免疫接种。”

原文链接>>

Nearly 100 Positive COVID-19 Tests Linked to Illinois Summer Camp

6/29/2021

QUINCY, Ill. (WGEM/CNN) – Nearly 100 teenagers and staff tested positive for COVID-19 after attending a church camp in rural Illinois.

‘The Crossing Camp’ was held in mid-June in Rushville. While majority of the campers and staff were eligible for the vaccine, Illinois Department of Health officials said few had been inoculated.

The health department said the camp did not require masks indoor. At least one young adult was hospitalized as a result of the outbreak.

Source>>

The Delta variant appears to have tripled to 31% of all US coronavirus cases in just 11 days. It’s more dangerous than other variants and could imperil the country’s recovery.

By Marianne Guenot

6/21/2021

covid vaccine — A medical assistant administering a COVID-19 vaccine dose in Los Angeles. Mario Tama/Getty Image

As of Wednesday, the Delta coronavirus variant may have been responsible for 31% of all coronavirus cases in the US, according to an estimate by the Financial Times.

Previous data from the Centers for Disease Control and Prevention put that share of cases at about 10% as of June 5 and 2.7% on May 22.

The Financial Times estimate, based on available sequencing data, would mean the share of Delta-variant infections in the US tripled in just 11 days.

The CDC has not yet released data on the rate of Delta-variant cases after June 5 in the US.

Dr. Rochelle Walensky, the director of the CDC, warned last week that the Delta variant could soon become dominant in the US.

And on Sunday, the former Food and Drug Administration chief Scott Gottlieb warned that the Delta variant could lead to a surge of cases in the fall even if 75% of eligible Americans were vaccinated by then.

The variant, which was first identified in India and is also called B.1.617.2, appears to be 60% more transmissible than the variant that is now still dominant in the US, the Alpha variant.

Data from the UK, where the Delta variant is thought to make up about 90% of current coronavirus cases, also suggests that the risk of hospitalization is higher for unvaccinated people with this variant.

The Delta variant also appears to more likely to evade the protection given by partial vaccinations.

Research suggests a single shot of the Pfizer-BioNTech or Oxford University-AstraZeneca coronavirus vaccines may give just 33% protection against symptomatic COVID-19 cases with the Delta variant, compared with at least 88% for other variants.

Two doses of the Pfizer-BioNTech or Oxford-AstraZeneca shot have been found to be protective against hospitalization from the variant, however.

It is not clear what protection other vaccines give against this variant.

On Friday, President Joe Biden warned that the Delta variant was “particularly dangerous for young people,” who are less likely to be vaccinated than older adults and are more socially active.

He also urged all Americans to get second doses of vaccines that require them.

As of Monday, 45% of Americans were fully vaccinated and 53% had received one dose, according to data from the CDC. The pace of vaccination, however, has fallen in the past two months.

Source: https://www.businessinsider.com/delta-coronavirus-variant-growing-in-us-could-imperil-recovery-2021-6