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新冠疫苗过敏反应全解

新冠疫苗过敏反应全解

John Lauerman, 彭博社 2021年01月04日
与所有新药一样,新冠疫苗也存在一些安全问题和副作用。

与所有新药一样,近期一些欧美国家批准通过的新冠疫苗也存在一些安全问题和副作用。许多接受了辉瑞(Pfizer Inc.)、BioNTech公司(BioNTech SE)及Moderna公司(Moderna Inc.)头两针疫苗的人,会出现发烧、头痛和注射部位疼痛的症状,但这些副作用通常很快就会消失。目前,已经有至少10人对疫苗产生了严重的过敏性反应。

1. 何为过敏性反应?

人体通过多种机制对抗外来入侵者,其中就包括产生“抗体”这一保护性蛋白质。抗体释放杀死微生物的毒素,同时集结保卫细胞以对抗感染的威胁。在对抗的过程中,“抵御感染”这一过程本身就可能有害,在极少数情况下甚至会产生失控性炎症和组织肿胀——这种反应被称为“过敏性反应”。

在美国,有5%的人对各类物质会产生如上反应。例如,一些人的气道因为膨胀而堵塞,就可能致命(不过死亡的情况很少见)。此外,对昆虫叮咬和食物过敏也会引发过敏性反应。

2. 新冠疫苗的过敏病例出现在哪些地方?

美国疾病控制与预防中心(U.S. Centers for Disease Control and Prevention)在2020年12月19日的报告中提到了8例与辉瑞疫苗相关的过敏反应病例(2例在英国,6例在美国)。阿拉斯加州的一名卫生保健工作者在注射了疫苗后住院了一整夜。据《耶路撒冷邮报》(Jerusalem Post)报道,2020年12月晚些时候,接种了辉瑞和BioNTech疫苗的一名以色列男子在注射后一小时发生过敏性休克,报道称他自己之前对青霉素有过敏反应。此外,波士顿一位对贝类过敏的医生报告说他对Moderna公司的疫苗有过敏反应。不过这些病例都没有导致死亡。

3. 之前的疫苗也会出现过敏反应吗?

是的。2016年发表在《过敏与临床免疫学杂志》(Journal of Allergy and Clinical Immunology)上的一项研究发现,在接种25173965剂疫苗后,经证实发生了33例疫苗引发的过敏反应,发生率约为1.31例/每百万剂。截至目前,注射大约300万剂辉瑞和Moderna疫苗导致的已知病例发生率约为这个数字的两倍多,但仍然很低。

4. 过敏风险将会持续多久?

通常不长。药物开发专家、圣路易斯华盛顿大学(Washington University in St. Louis)副校长迈克尔•金奇说,过敏反应通常发生在接触物质之后的几分钟到几小时内。2016年的研究记录的29例过敏反应时间间隔中,有8例在30分钟内发病,有8例在90分钟内发病,有10例在2到4个小时内发病,有2例在4至8小时内发病,另有一例在第二天发病。

5. 应当怎么解决?

英美两国建议,对新冠疫苗的任何成分过敏的人,不要接种疫苗。

一旦发生过敏性反应,可以通过抗组胺剂和肾上腺素注射器(例如Mylan NV公司的Epi-Pen)解决,即刻减缓或停止过敏反应,接种疫苗的卫生人员会随时准备这些物品。并且,对过敏反应的治疗不会抵消疫苗的有益作用。在美国,卫生人员会对疫苗接种者进行至少15分钟的过敏迹象观察。美国疾病控制与预防中心表示,对第一剂疫苗有过敏反应者不应该再接种第二剂疫苗。

6. 我们清楚引发过敏反应的原因吗?

尚不清楚。临床试验专家、斯克里普斯转化研究所(Scripps Research Translational Institute)的主任埃里克•托波尔表示,两种主要候选药物的成分是聚乙二醇(存在于许多食品、化妆品和药物中)以及包裹mRNA(疫苗中的遗传成分)的脂质纳米颗粒——而其中聚乙二醇此前曾经与少数过敏反应病例有关。

托波尔说,一旦缩小了病因范围,新冠疫苗就有可能比现在更安全。他说,如果出现其他严重的非过敏副作用,“也可能相当罕见,但对疫苗接种的净效益来说是有好处的。”(财富中文网)

编译:杨二一

与所有新药一样,近期一些欧美国家批准通过的新冠疫苗也存在一些安全问题和副作用。许多接受了辉瑞(Pfizer Inc.)、BioNTech公司(BioNTech SE)及Moderna公司(Moderna Inc.)头两针疫苗的人,会出现发烧、头痛和注射部位疼痛的症状,但这些副作用通常很快就会消失。目前,已经有至少10人对疫苗产生了严重的过敏性反应。

1. 何为过敏性反应?

人体通过多种机制对抗外来入侵者,其中就包括产生“抗体”这一保护性蛋白质。抗体释放杀死微生物的毒素,同时集结保卫细胞以对抗感染的威胁。在对抗的过程中,“抵御感染”这一过程本身就可能有害,在极少数情况下甚至会产生失控性炎症和组织肿胀——这种反应被称为“过敏性反应”。

在美国,有5%的人对各类物质会产生如上反应。例如,一些人的气道因为膨胀而堵塞,就可能致命(不过死亡的情况很少见)。此外,对昆虫叮咬和食物过敏也会引发过敏性反应。

2. 新冠疫苗的过敏病例出现在哪些地方?

美国疾病控制与预防中心(U.S. Centers for Disease Control and Prevention)在2020年12月19日的报告中提到了8例与辉瑞疫苗相关的过敏反应病例(2例在英国,6例在美国)。阿拉斯加州的一名卫生保健工作者在注射了疫苗后住院了一整夜。据《耶路撒冷邮报》(Jerusalem Post)报道,2020年12月晚些时候,接种了辉瑞和BioNTech疫苗的一名以色列男子在注射后一小时发生过敏性休克,报道称他自己之前对青霉素有过敏反应。此外,波士顿一位对贝类过敏的医生报告说他对Moderna公司的疫苗有过敏反应。不过这些病例都没有导致死亡。

3. 之前的疫苗也会出现过敏反应吗?

是的。2016年发表在《过敏与临床免疫学杂志》(Journal of Allergy and Clinical Immunology)上的一项研究发现,在接种25173965剂疫苗后,经证实发生了33例疫苗引发的过敏反应,发生率约为1.31例/每百万剂。截至目前,注射大约300万剂辉瑞和Moderna疫苗导致的已知病例发生率约为这个数字的两倍多,但仍然很低。

4. 过敏风险将会持续多久?

通常不长。药物开发专家、圣路易斯华盛顿大学(Washington University in St. Louis)副校长迈克尔•金奇说,过敏反应通常发生在接触物质之后的几分钟到几小时内。2016年的研究记录的29例过敏反应时间间隔中,有8例在30分钟内发病,有8例在90分钟内发病,有10例在2到4个小时内发病,有2例在4至8小时内发病,另有一例在第二天发病。

5. 应当怎么解决?

英美两国建议,对新冠疫苗的任何成分过敏的人,不要接种疫苗。

一旦发生过敏性反应,可以通过抗组胺剂和肾上腺素注射器(例如Mylan NV公司的Epi-Pen)解决,即刻减缓或停止过敏反应,接种疫苗的卫生人员会随时准备这些物品。并且,对过敏反应的治疗不会抵消疫苗的有益作用。在美国,卫生人员会对疫苗接种者进行至少15分钟的过敏迹象观察。美国疾病控制与预防中心表示,对第一剂疫苗有过敏反应者不应该再接种第二剂疫苗。

6. 我们清楚引发过敏反应的原因吗?

尚不清楚。临床试验专家、斯克里普斯转化研究所(Scripps Research Translational Institute)的主任埃里克•托波尔表示,两种主要候选药物的成分是聚乙二醇(存在于许多食品、化妆品和药物中)以及包裹mRNA(疫苗中的遗传成分)的脂质纳米颗粒——而其中聚乙二醇此前曾经与少数过敏反应病例有关。

托波尔说,一旦缩小了病因范围,新冠疫苗就有可能比现在更安全。他说,如果出现其他严重的非过敏副作用,“也可能相当罕见,但对疫苗接种的净效益来说是有好处的。”(财富中文网)

编译:杨二一

Like all new drugs, the Covid-19 vaccines that have been authorized in Western countries come with some safety concerns and side effects. Many people who’ve received the first two shots deployed, one from Pfizer Inc. and BioNTech SE and another from Moderna Inc., have experienced fever, headache and pain at the site of the injection. These side effects generally disappear quickly. As many as 10 people have had a serious allergic reaction, called anaphylaxis, to the vaccines.

1. What is anaphylaxis?

The body fights foreign invaders through a variety of mechanisms that include making protective proteins called antibodies, releasing toxins that kill microbes, and marshaling guardian cells to battle the infection. As in any conflict, sometimes the effort to repel an infection can itself be damaging. In rare cases, it can produce runaway inflammation and swelling of tissues in a serious allergic reaction called anaphylaxis.

As much as 5% of people in the U.S. have had such a reaction to various substances. It can be fatal if, for example, the person’s airway swells shut, though deaths are rare. Allergies to insect stings and foods can provoke it.

2. Where have Covid vaccines triggered cases?

A Dec. 19 presentation from the U.S. Centers for Disease Control and Prevention referenced two cases of anaphylaxis associated with the Pfizer-BioNTech vaccine in the U.K. and six in the U.S. A health-care worker in Alaska who received a shot had to be hospitalized overnight. Later in the month, in Israel, which is deploying the Pfizer-BioNTech vaccine, a man suffered anaphylactic shock an hour after receiving a shot, according to the Jerusalem Post. He said he’d had earlier reactions to penicillin, the paper reported. And a physician in Boston with a shellfish allergy reported having an anaphylactic reaction to Moderna’s vaccine. None of the reactions resulted in death.

3. Has anaphylaxis been connected to vaccines before?

Yes. A 2016 study in the Journal of Allergy and Clinical Immunology found 33 confirmed vaccine-triggered anaphylaxis cases that occurred after 25,173,965 doses of inoculations, a rate of about 1.31 per million doses. So far, the rate for known cases connected to administration of approximately 3 million doses of the Pfizer and Moderna vaccines appears to be more than double that, but still very low.

4. How long does the risk last?

Usually not long. Anaphylactic reactions normally occur within minutes to hours of exposure to a specific substance, said Michael Kinch, a drug development expert and associate vice chancellor at Washington University in St. Louis. Of the 29 cases where the time lag was documented in the 2016 study, symptoms of anaphylaxis began within 30 minutes in eight cases, within the next 90 minutes in another eight, within two to four hours in 10 cases, within four to eight hours in two cases, and the next day in one.

5. What’s being done about the risk?

The U.K. and U.S. have advised people who have allergies to any component of a Covid vaccine not to receive it.

Anaphylaxis can be quickly countered with antihistamines and adrenaline injectors like Mylan NV’s Epi-Pen that slow or halt immune reactions, and health workers giving the vaccine are keeping such items at the ready. These treatments don’t cancel out the beneficial effects of vaccines. In the U.S., health workers are observing anyone who has received the vaccine for at least 15 minutes post-injection to watch for signs of a reaction. People who have had reactions to a first dose of vaccine shouldn’t receive a second, according to the CDC.

6. Do we know what in the shots is causing the reactions?

That isn’t clear. The two leading candidates are polyethylene glycol -- a chemical found in many foods, cosmetics and medications -- and lipid nanoparticles that encapsulate the messenger RNA, a genetic component in the vaccines, according to Eric Topol, a clinical trials expert and director of the Scripps Research Translational Institute. Polyethylene glycol has been previously linked to a handful of anaphylaxis cases.

Once a cause has been narrowed down, it may be possible to make Covid vaccines even safer than they are now, Topol said. If other serious non-allergic side effects crop up, he said, “they, too, are likely to be quite rare and the net benefit of vaccination overwhelmingly positive.”

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