美國籲推動施打強化劑 是否能提高免疫力成關鍵 | What do we know about booster shots for COVID-19?

Will one dose of a two-dose COVID-19 vaccine protect me? (AP Illustration/Peter Hamlin)

【看CP學英文】美國衛生官員表示將來可能會提供已接種兩劑疫苗的美國人注射COVID-19(新冠肺炎)強化劑。

U.S. health officials may soon recommend COVID-19 booster shots for fully vaccinated Americans.

以下為美聯社對強化劑的研究、它如何幫助人體對抗新冠病毒和為什麼我們可能需要強化劑。

A look at what we know about boosters and how they could help fight the coronavirus: Why might we need boosters?

疫苗的保護作用隨著時間的推移而減弱是常見的現象。就如破傷風,醫師會建議每10年施打一次強化劑。

It’s common for protection from vaccines to decrease over time. A tetanus booster, for example, is recommended every 10 years.

各國的研究人員與衛生官員一直在監測COVID-19疫苗的實際性能,以了解在接種後能給予多久的保護力。在美國公認可使用的疫苗仍持續提供有效的保護,有效預防重症與死亡案例增加。

Researchers and health officials have been monitoring the real-world performance of the COVID-19 vaccines to see how long protection lasts among vaccinated people. The vaccines authorized in the U.S. continue to offer very strong protection against severe disease and death.

但是實驗室血液測試顯示,「抗體」,也就是免疫系統的保護層之一,會隨著時間的推移而減弱。這並不代表保護作用消失,但它可能意味著保護作用會比剛接種時的效果弱,或者身體可能需要更長的時間來抵抗感染。

But laboratory blood tests have suggested that antibodies — one of the immune system’s layers of protection — can wane over time. That doesn’t mean protection disappears, but it could mean protection is not as strong or that it could take longer for the body to fight back against an infection.

因為Delta變種病毒的傳染性相較其它病毒更強,這讓何時該進行強化劑接種計畫的問題變得更複雜。再加上收集到的相關疫苗性能數據都是在Delta變種病毒廣泛流傳之前,Delta變種病毒正在持續肆虐,與此同時,第一批接種疫苗的人,疫苗免疫力可能也在減弱。

The delta variant has complicated the question of when to give boosters because it is so much more contagious and much of the data gathered about vaccine performance is from before the delta variant was widely circulating. Delta is taking off at the same time that vaccine immunity might also be waning for the first people vaccinated.

如今,以色列正在向五個多月前接種過疫苗的50歲以上人民提供強化劑,而法國與德國正計畫在秋季為一些人施打強化劑。同時,歐洲藥品管理局(EMA)表示,目前在調查數據以確認是否需要施打強化劑。

Israel is offering a booster to people over 50 who were vaccinated more than five months ago. France and Germany plan to offer boosters to some people in the fall. The European Medicines Agency said it too is reviewing data to see if booster shots are needed.

何時能注射? | When should they (boosters) be given?

如果未來確定推動強化劑,何時能注射新的強化劑取決於什麼時候施打第一劑疫苗。衛生官員提出的一個建議是,人們施打完BNT(輝瑞)或Moderna(莫德納)第二劑疫苗後,等待約8個月後再施打強化劑。

It depends on when you got your initial shots. One possibility is that health officials will recommend people get a booster roughly eight months after getting their second shot of the Pfizer or Moderna vaccine.

美國官員們也正持續收集有關Johnson & Johnson(嬌生集團) 的一次性疫苗數據,該疫苗於今年2月底剛獲得美國批准,未來也將確定何時推動強化劑。

Officials are continuing to collect information about the one-shot Johnson & Johnson vaccine, which was approved in the U.S. in late February, to determine when to recommend boosters.

誰可以施打強化劑? | Who would get them? 

美國第一批接種疫苗的人很可能會是接受強化注射的優先族群。這意味去年12月在疫苗被批准後首先接種的人,如醫護人員、養老院居民和其他美國年老長者將會是第一批接受疫苗強化劑的人。

The first people vaccinated in the United States would likely be first in line for boosters too. That means health care workers, nursing home residents, and other older Americans, who were the first to be vaccinated once the shots were authorized last December.


強化劑和第三劑,兩者有何區別?| Booster? Third shot? What’s the difference?

移植對象和其他免疫系統較弱的人可能從一開始就沒有得到足夠的疫苗保護。他們現在可以在接種第二針後至少28天後接種第三針,作為他們最初所需系列疫苗的一部分,使他們得到充分的免疫力。

相對的,對於那些免疫系統正常的人來說,在完全接種疫苗後,強化劑要在時隔更久之後才能接種,因為它不是為了建立保護力,而是為了再次提升保護。

Transplant recipients and other people with weakened immune systems may not have gotten enough protection from vaccines, to begin with. They can now receive a third dose at least 28 days after their second shot as part of their initial series of shots needed for them to be fully vaccinated. For those with normal immune systems, boosters are given much later after full vaccination — not to establish protection, but to rev it up again.

疫苗還有什麼問題? | What questions remain?

目前未知的是,人們是否應該注射與他們第一次接種時相同類型的疫苗。美美國最專業的公衛保健專家也正在尋找有關強化劑安全性的證據,研究它們對新冠感染類和其他嚴重疾病的保護程度。

Still unknown is whether people should get the same type of shot they got when first vaccinated. And the nation’s top health advisers will be looking for evidence about the safety of boosters and how well they protect against infection and severe disease.

阻止大流行疾病和防止新的變種病毒出現的關鍵在於讓各國都能獲得疫苗為。強化劑可能會增加全球疫苗供應量的壓力。

Global access to vaccines is also important to stem the pandemic and prevent the emergence of new variants. Booster shots could crimp already tight global vaccine supplies.

未接種疫苗的人們怎麼辦? | What about the unvaccinated?

明尼蘇達州羅切斯特梅奧診所的梅蘭妮.斯威夫特 (Dr. Melanie Swift) 醫師為疫苗接種計劃的領導人之一。她表示,「給那些還沒有接種過疫苗的人打更多的疫苗是我們最佳的辦法,不僅是為了防止更多感染Delta變種病毒病人的住院率和死亡率,更是為了阻斷傳播」。

她補充道,「每一次的感染都給了病毒更多的機會去突變,誰知道下一個變種病株會是什麼」。

Dr. Melanie Swift, who has been leading the vaccination program at Mayo Clinic in Rochester, Minnesota, says getting more shots into people who haven’t yet been vaccinated at all is “our best tool, not only to prevent hospitalization and mortality from the delta variant but to stop transmission.” Every infection, she says, “gives the virus more chances to mutate into who knows what the next variant could be.”

斯威夫特表示,「第一時間就接種疫苗的人很可能會排隊接受接種強化劑,但是如果他們所有未施打疫苗的鄰居都不接種疫苗,這就無法實現國家群體免疫的總體目標。」。

“People who took the vaccine the first time are likely to line up and get their booster,” Swift says. “But it’s not going to achieve our goals overall if all their unvaccinated neighbors are not vaccinated.”