今年夏初，一些新冠疫苗接种率较高的国家眼看着即将迎来抗疫之战的转折，然而，传播性极强的德尔塔变异毒株来势汹汹，导致多国不得不开启新一轮的防疫限制措施。
近日，世卫组织总干事谭德塞也表示，“世界正面临真正的危险，我们已经取得的防疫成果正在被侵蚀。”
面对肆虐的德尔塔以及新一波的疫情反弹，已有部分国家宣布或正考虑为部分人群打新冠疫苗第三剂加强针。
Earlier this summer, countries with high vaccination rates were ready to turn a corner in the battle against the COVID-19 pandemic. But the spread of the highly contagious Delta variant in recent weeks has dampened that prospect and forced governments to reintroduce preventive measures.
To safeguard their return to normalcy, several countries that had already lifted most COVID-19 restrictions are starting to offer a third dose of the vaccine.
#1#
谁在打疫苗加强针？
7月29日，以色列总理宣布，该国将为60岁以上已完成疫苗接种的人提供第三剂新冠疫苗加强针。这一决定宣布时，该国国内感染病例正不断上升。
以色列卫生专家认为，随着时间的推移，疫苗效力变弱了。今年早些时候，以色列堪称全球疫苗接种最成功的国家之一。
On Sunday, Israel started administering third shots to people over the age of 60. The country was among the first to embrace normal post-pandemic life after vaccinating more than 70 percent of its population earlier this year.
But with more “breakthrough” cases reported since the Delta variant became widespread, Israeli health experts believe the immunity offered by the original shots declines in people vaccinated over five months ago.
另外，英国计划在9月初为已经完成新冠疫苗接种的3200万人提供加强针，最早将在9月6日启动。
德国与法国已有一半人口完成了新冠疫苗接种，这两个国家都计划从9月起为年老的人以及易感人群提供新冠疫苗加强针。
除此之外，有报道称，日本、加拿大、瑞士以及新加坡等国家也有计划在今年冬季或明年春季为民众提供加强针。
A similar situation is seen in Britain, which reopened its economy on July 19. Starting September, 32 million vaccinated Britons will be offered additional shots.
Germany and France, both with around half their population fully vaccinated, will give booster shots to elderly and vulnerable people from September.
Meanwhile, other countries with the ability to do so, including Japan, Canada, Switzerland and Singapore, are reportedly planning such a move in winter or early next year.
#2#
注射加强针是否有科学依据？
加强针能够提供额外的保护吗？接种加强针真的有必要吗？这已成为各国政府和科研界探讨的话题。
7月，美疾控中心与美食品和药物管理局曾联合发布声明说，已完成两剂疫苗接种的美国人当下没必要接种第三剂，但如果科学证明确实需要加强针，这两个部门也“已做好准备”。
随后，欧洲药品管理局也发文称，现在判断是否以及何时需接种第三剂疫苗还“为时过早”。
The U.S. Center for Disease Control (CDC) and the Food and Drug Administration (FDA) said in a joint statement that fully vaccinated Americans do not need a booster shot at this time, though the health regulators have indicated that a third shot may be needed for some high-risk groups.
同样在7月，美国辉瑞制药有限公司和德国生物新技术公司发表联合声明称，注射辉瑞疫苗（BNT162b2）第三剂加强针有望帮助人体提高对包括德尔塔毒株在内的多种变异新冠病毒的抵御能力。
声明中说，接种第三剂疫苗试验的初步数据显示，接种第二剂疫苗6个月后注射第三剂，人体内抵御新冠病毒和变异病毒贝塔毒株的中和抗体水平比接种两剂时提高了5到10倍。
也有其他疫苗制造商支持为人们接种加强针。美国制药商莫德纳（Moderna）的联合创始人德里克•罗西甚至表示，“就算每年需要接种一次加强针也不令人感到吃惊。”
Citing its non-peer-reviewed study last week, Pfizer suggested that a third dose of its COVID-19 vaccine can significantly increase protection against the Delta variant. Other vaccine makers also supported the idea. Moderna co-founder Derrick Rossi even went as far as saying “it might not be surprising that we need a booster shot every year.”
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世卫组织呼吁关注疫苗不公平问题
当一些富裕国家开始制定加强针的接种计划时，许多贫穷国家却面临疫苗供应不足的情况。
世卫组织称，高收入国家的每100人中接种了约100剂疫苗；由于缺乏供应，低收入国家每100人只接种了约1.5剂疫苗。
当地时间8月4日，世卫组织总干事谭德塞表示，富裕国家9月底之前应暂停注射新冠疫苗加强针，以确保每个国家都有至少10%的人口能打上疫苗。
“正如我们所看到的，一个又一个病毒变种出现了。除非全世界一起摆脱病毒，否则我们根本无法彻底摆脱它，”谭德塞的高级顾问布鲁斯•艾尔沃德说道，“如今疫苗接种覆盖率存在巨大差异，我们根本无法摆脱疫情。”
While some rich countries are rolling out third shots, many poorer countries are struggling to procure enough jabs for their people to begin.
High-income countries administered around 100 doses for every 100 people, whereas low-income countries have only been able to provide 1.5 doses per 100 people due to lack of supplies, according to WHO Director-General Tedros Adhanom Ghebreyesus, who appealed to wealthier countries to help address the huge disparity and ensure that at least 10 percent of the population in every country is vaccinated.
“As we’ve seen from the emergence of variant after variant, we cannot get out of it unless the whole world gets out of it together,” said Dr. Bruce Aylward, a special adviser to Tedros. “And with the huge disparity in vaccination coverage, we are simply not going to be able to achieve that.”