面对新冠病毒的新变种，辉瑞力争疫苗加强针在8月获批
辉瑞公司计划在8月向美国监管部门申请，紧急批准新冠疫苗第三针加强针。早期数据显示，疫苗加强针可以大幅增强对新冠病毒的防护效果。
辉瑞的研究主管米卡埃尔·多尔斯滕在接受采访时称，公司已经获得早期人体研究原始数据，显示现有新冠病毒疫苗注射第三针是安全的，与原有疫苗相比，能够将中和抗体水平提高5至10倍。
多尔斯滕说，一旦掌握了更多的数据，辉瑞就打算申请美国食品与药品监督管理局批准加强针，可以在最初两针之后的6到8个月注射。他表示，辉瑞还与其他国家和欧盟的监管机构介绍了新测试结果。目前辉瑞与BioNTech公司合作生产疫苗。
多尔斯滕指出，由于早期数据看起来很有说服力，而且人们越发担心变异病毒，包括当前正在多国蔓延传染性超强的德尔塔变异病毒，所以公司将公开计划。
“人们非常担心，也很恐惧变异病毒。”他说，“我们确信加强针能够高效防护德尔塔变异病毒。”
抗体结果样本不大，只有10到20人注射了加强针。不过多尔斯滕称，“数据集合结果很清晰，我们充分相信全面研究可以重现相同的结果。”
以色列出现突破性案例
mRNA疫苗能够有效防护新冠肺炎重症，也包括德尔塔变异病毒感染，但已经出现了突破性病例的迹象。举例来说，英国在5月进行的一项研究发现，注射第二针辉瑞疫苗后，对预防德尔塔变异病毒导致明显症状的有效性为88%。
本月以色列公布的最新数据显示，自从德尔塔变异病毒流行以来，辉瑞疫苗的有效性已经降至64%，不过在防止重症住院方面的有效性达93%。
多尔斯滕说，辉瑞对以色列数据的解读为，自1月和2月以色列民众开始接种疫苗以来，血液中的抗体水平有所下降。他认为，在传染性超强的变异病毒蔓延期间，人们虽然不会出现重症，但仍然可能存在轻症传播。
多尔斯滕指出，即便一线抗体的效力略减，疫苗仍然能够激发多种记忆反应，可以抵御重症。
“血液中抗体水平较低时，传染性超强的病毒可能再次感染，并导致轻症。”他说。
对付德尔塔变异病毒的加强针
辉瑞打算专门针对德尔塔病毒，开始为新加强针展开人体试验。但多尔斯滕表示，不太可能需要定制疫苗，因为现有疫苗针对变异病毒产生抗体方面的效果已经很好。
他说，只要能够预防轻症就可以发挥作用，因为有助于减缓可能引发新变异的感染，也能够预防轻微感染后可能导致的长期新冠肺炎病例。
之前，辉瑞的首席执行官艾伯乐（Albert Bourla）曾经建议，多数人可能在12个月内需要注射新冠疫苗加强针，此后可能每年要注射一次。但医学专家警告说，尚不清楚是否需要加强针，以及何时需要。
多尔斯滕指出，现在全世界只有一小部分地区接种了疫苗，而且变异病毒层出不穷，注射疫苗加强针可能是重要的预防手段，可以让已经接种疫苗的地区不必持续采取影响正常生活秩序的隔离措施。
“未来几年里，最好是放弃等待奇迹出现，为严肃的现实做好准备。”他说。
辉瑞的疫苗是全球领先的新冠疫苗之一。辉瑞公司表示，截至7月1日，已经向全球分发超过8.6亿剂疫苗，其中3.3亿多剂销往欧盟，2亿多剂销往美国。
据美国疾病控制和预防中心（Centers for Disease Control and Prevention）统计，目前美国注射的辉瑞疫苗超过1.84亿剂，已经超过1.35亿剂的Moderna疫苗。（财富中文网）
译者：冯丰
辉瑞公司计划在8月向美国监管部门申请，紧急批准新冠疫苗第三针加强针。早期数据显示，疫苗加强针可以大幅增强对新冠病毒的防护效果。
辉瑞的研究主管米卡埃尔·多尔斯滕在接受采访时称，公司已经获得早期人体研究原始数据，显示现有新冠病毒疫苗注射第三针是安全的，与原有疫苗相比，能够将中和抗体水平提高5至10倍。
多尔斯滕说，一旦掌握了更多的数据，辉瑞就打算申请美国食品与药品监督管理局批准加强针，可以在最初两针之后的6到8个月注射。他表示，辉瑞还与其他国家和欧盟的监管机构介绍了新测试结果。目前辉瑞与BioNTech公司合作生产疫苗。
多尔斯滕指出，由于早期数据看起来很有说服力，而且人们越发担心变异病毒，包括当前正在多国蔓延传染性超强的德尔塔变异病毒，所以公司将公开计划。
“人们非常担心，也很恐惧变异病毒。”他说，“我们确信加强针能够高效防护德尔塔变异病毒。”
抗体结果样本不大，只有10到20人注射了加强针。不过多尔斯滕称，“数据集合结果很清晰，我们充分相信全面研究可以重现相同的结果。”
以色列出现突破性案例
mRNA疫苗能够有效防护新冠肺炎重症，也包括德尔塔变异病毒感染，但已经出现了突破性病例的迹象。举例来说，英国在5月进行的一项研究发现，注射第二针辉瑞疫苗后，对预防德尔塔变异病毒导致明显症状的有效性为88%。
本月以色列公布的最新数据显示，自从德尔塔变异病毒流行以来，辉瑞疫苗的有效性已经降至64%，不过在防止重症住院方面的有效性达93%。
多尔斯滕说，辉瑞对以色列数据的解读为，自1月和2月以色列民众开始接种疫苗以来，血液中的抗体水平有所下降。他认为，在传染性超强的变异病毒蔓延期间，人们虽然不会出现重症，但仍然可能存在轻症传播。
多尔斯滕指出，即便一线抗体的效力略减，疫苗仍然能够激发多种记忆反应，可以抵御重症。
“血液中抗体水平较低时，传染性超强的病毒可能再次感染，并导致轻症。”他说。
对付德尔塔变异病毒的加强针
辉瑞打算专门针对德尔塔病毒，开始为新加强针展开人体试验。但多尔斯滕表示，不太可能需要定制疫苗，因为现有疫苗针对变异病毒产生抗体方面的效果已经很好。
他说，只要能够预防轻症就可以发挥作用，因为有助于减缓可能引发新变异的感染，也能够预防轻微感染后可能导致的长期新冠肺炎病例。
之前，辉瑞的首席执行官艾伯乐（Albert Bourla）曾经建议，多数人可能在12个月内需要注射新冠疫苗加强针，此后可能每年要注射一次。但医学专家警告说，尚不清楚是否需要加强针，以及何时需要。
多尔斯滕指出，现在全世界只有一小部分地区接种了疫苗，而且变异病毒层出不穷，注射疫苗加强针可能是重要的预防手段，可以让已经接种疫苗的地区不必持续采取影响正常生活秩序的隔离措施。
“未来几年里，最好是放弃等待奇迹出现，为严肃的现实做好准备。”他说。
辉瑞的疫苗是全球领先的新冠疫苗之一。辉瑞公司表示，截至7月1日，已经向全球分发超过8.6亿剂疫苗，其中3.3亿多剂销往欧盟，2亿多剂销往美国。
据美国疾病控制和预防中心（Centers for Disease Control and Prevention）统计，目前美国注射的辉瑞疫苗超过1.84亿剂，已经超过1.35亿剂的Moderna疫苗。（财富中文网）
译者：冯丰
Pfizer Inc. plans to request U.S. emergency authorization in August for a third booster dose of its COVID-19 vaccine, based on early data showing that it can sharply increase immune protection against the coronavirus.
The company has received initial data from an early human study showing that a third dose of its existing coronavirus vaccine is safe and can raise neutralizing antibody levels by 5 to 10 fold compared with the original vaccine, Pfizer research head Mikael Dolsten said in an interview.
Once more data is in hand, Pfizer plans to ask the FDA to authorize a booster shot that could be given six to eight months after the original two doses, Dolsten said. The drugmaker is also talking with regulators in other countries and the European Union about the new results, he said. Pfizer produces the vaccine in partnership with BioNTech SE.
Dolsten said the company is going public with its plans because the early data looks convincing and because of increasing concern about mutations of the virus, including the ultra-transmissible Delta variant that is spreading in numerous countries.
“There is a lot of fear and concern” about variants, Dolsten said. “We are confident that such a boost will be highly effective against the Delta variant.”
While the antibody results are based on a small initial cohort of roughly 10 to 20 people who received the booster, Dolsten said that the “the data set is so clear we have complete confidence that the full study will reproduce this.”
Breakthrough cases in Israel
Messenger RNA vaccines provide powerful protection against severe COVID-19, including cases caused by the Delta strain, but there have been signs of breakthrough cases. A British study in May, for example, found the Pfizer shot was 88% effective in preventing symptomatic disease from the Delta variant after the second dose.
More recent data released by Israel this month found that Pfizer’s efficacy had dropped to 64% since the Delta variant took over there, even as it was 93% effective at keeping people out of the hospital.
Dolsten said Pfizer interprets the Israel finding as a sign that blood-antibody levels have faded somewhat since people in Israel started being vaccinated in January and February. In the presence of a highly transmissible strain, that may allow mild cases to slip through even though people remain protected against severe disease, he said.
Even when front-line antibodies have faded slightly, the vaccine still produces a variety of memory responses that can stave off severe disease, Dolsten said.
“When you have low blood levels of an antibody, viruses that are highly contagious may reinfect and cause mild disease,” Dolsten said.
A booster against the Delta variant
Separately, Pfizer plans to begin human trials of a new booster customized against the Delta strain. But Dolsten said it was unlikely that this customized vaccine will be needed, as the existing vaccine does a good job of producing antibodies against the variant.
Even preventing mild cases can be useful because it will help slow infections that can lead to new variants, and will prevent cases of long Covid that can occur even after mild infections, Dolsten said.
In the past, Pfizer Chief Executive Officer Albert Bourla has suggested that Covid booster shots may be needed for most people within 12 months, and annual boosters might be needed after that. But medical experts have cautioned that it isn’t clear whether and when boosters will be needed.
With only a small portion of the world vaccinated so far and variants emerging like wildfire, booster shots may be an important way to keep vaccinated parts of the world from having to continually going back to disruptive social distancing measures, Dolsten said.
“For the next few years, it is better to be prepared for what seems like a sober reality than to hold for miracles,” he said.
The Pfizer shot is one of the leading Covid vaccines globally. As of July 1, Pfizer said it had shipped more than 860 million doses of its vaccine around the world, including over 330 million doses to the EU and over 200 million doses to the U.S.
In the U.S., over 184 million doses of the Pfizer vaccine have been administered so far, outpacing 135 million doses of Moderna Inc.’s vaccine that have been used in the country, according to the Centers for Disease Control and Prevention.
