美國疾病預(yù)防控制中心(U.S. Centers for Disease Control)宣布,赴美旅客無需出具新冠檢測陰性證明或者康復(fù)證明。
美國疾控中心在上周五的新聞發(fā)布會上宣布,從周日開始取消相關(guān)要求。美國從去年1月開始要求赴美旅客提供陰性證明或康復(fù)證明。外國旅客依舊需要出具新冠疫苗接種證明。
美國疾控中心官員在發(fā)布會上表示:“新冠疫情現(xiàn)在已經(jīng)進(jìn)入了新階段”,包括“高度有效的”疫苗和美國人“高疫苗接種率和感染誘導(dǎo)的免疫力”等因素。
疾控中心官員稱:“這些措施降低了美國的重癥和死亡風(fēng)險(xiǎn)?!钡部刂行囊琅f建議赴美旅客在出發(fā)前三天內(nèi)進(jìn)行檢測,一旦感染應(yīng)取消行程。
疾控中心的數(shù)據(jù)顯示,截至周日,美國有近78%的人口已經(jīng)接種疫苗。此外,疾控中心根據(jù)商業(yè)實(shí)驗(yàn)室提供的抗體水平估計(jì),近58%的美國人已經(jīng)至少感染一次新冠。
然而眾所周知,奧密克戎變異株具有免疫逃脫能力,尤其是兩種相對較新的亞變種BA.4和BA.5被認(rèn)為是到目前為止傳播力最強(qiáng)的變異株,并且有資料證明它們能夠逃脫疫苗和之前感染產(chǎn)生的免疫力。
據(jù)疾控中心統(tǒng)計(jì),美國BA.4和BA.5感染者的比例不斷提高,到兩周前分別占感染者的5%和8%。
這兩種變異株是否會像今年春天早些時(shí)候在南非時(shí)一樣,成為美國的主要病毒株,現(xiàn)在仍是個(gè)未知數(shù),但它們已經(jīng)證明有與目前的主要病毒株B.2.12.1競爭的能力。兩周前,B.2.12.1感染者的比例為62%,BA.1感染者占25%。
此外,雖然疫苗能夠降低重癥和死亡風(fēng)險(xiǎn),但它無法阻止或至少無法完全阻止新冠病毒的傳播。世界衛(wèi)生組織(World Health Organization)稱,突破性感染依舊會發(fā)生,而且“目前仍在進(jìn)行相關(guān)研究,以了解接種疫苗能在多大程度上防止感染和傳播病毒。”
世衛(wèi)組織建議,為保護(hù)他人,已完成疫苗接種的人員應(yīng)該繼續(xù)采取預(yù)防措施,如配戴口罩和保持社交距離等。(財(cái)富中文網(wǎng))
譯者:劉進(jìn)龍
審校:汪皓
美國疾病預(yù)防控制中心(U.S. Centers for Disease Control)宣布,赴美旅客無需出具新冠檢測陰性證明或者康復(fù)證明。
美國疾控中心在上周五的新聞發(fā)布會上宣布,從周日開始取消相關(guān)要求。美國從去年1月開始要求赴美旅客提供陰性證明或康復(fù)證明。外國旅客依舊需要出具新冠疫苗接種證明。
美國疾控中心官員在發(fā)布會上表示:“新冠疫情現(xiàn)在已經(jīng)進(jìn)入了新階段”,包括“高度有效的”疫苗和美國人“高疫苗接種率和感染誘導(dǎo)的免疫力”等因素。
疾控中心官員稱:“這些措施降低了美國的重癥和死亡風(fēng)險(xiǎn)?!钡部刂行囊琅f建議赴美旅客在出發(fā)前三天內(nèi)進(jìn)行檢測,一旦感染應(yīng)取消行程。
疾控中心的數(shù)據(jù)顯示,截至周日,美國有近78%的人口已經(jīng)接種疫苗。此外,疾控中心根據(jù)商業(yè)實(shí)驗(yàn)室提供的抗體水平估計(jì),近58%的美國人已經(jīng)至少感染一次新冠。
然而眾所周知,奧密克戎變異株具有免疫逃脫能力,尤其是兩種相對較新的亞變種BA.4和BA.5被認(rèn)為是到目前為止傳播力最強(qiáng)的變異株,并且有資料證明它們能夠逃脫疫苗和之前感染產(chǎn)生的免疫力。
據(jù)疾控中心統(tǒng)計(jì),美國BA.4和BA.5感染者的比例不斷提高,到兩周前分別占感染者的5%和8%。
這兩種變異株是否會像今年春天早些時(shí)候在南非時(shí)一樣,成為美國的主要病毒株,現(xiàn)在仍是個(gè)未知數(shù),但它們已經(jīng)證明有與目前的主要病毒株B.2.12.1競爭的能力。兩周前,B.2.12.1感染者的比例為62%,BA.1感染者占25%。
此外,雖然疫苗能夠降低重癥和死亡風(fēng)險(xiǎn),但它無法阻止或至少無法完全阻止新冠病毒的傳播。世界衛(wèi)生組織(World Health Organization)稱,突破性感染依舊會發(fā)生,而且“目前仍在進(jìn)行相關(guān)研究,以了解接種疫苗能在多大程度上防止感染和傳播病毒。”
世衛(wèi)組織建議,為保護(hù)他人,已完成疫苗接種的人員應(yīng)該繼續(xù)采取預(yù)防措施,如配戴口罩和保持社交距離等。(財(cái)富中文網(wǎng))
譯者:劉進(jìn)龍
審校:汪皓
Travelers to the U.S. no longer have to show proof of a negative COVID-19 test or documentation of recovery from the virus, according to the U.S. Centers for Disease Control.
The order was lifted Sunday, according to a Friday news release from the federal health agency. It had been in place since January of last year. Foreign travelers must still show proof of COVID-19 vaccination.
“The COVID-19 pandemic has now shifted to a new phase,” officials said in the release, citing “highly effective” vaccines and “high rates of vaccine- and infection-induced immunity” among Americans, among other factors.
“Each of these measures has contributed to lower risk of severe disease and death across the United States,” officials said, adding that the agency still recommends travelers coming to the U.S. get tested within three days of departure and do not travel if they are sick.
Nearly 78% of the U.S. population had been vaccinated as of Sunday, according to CDC data. Additionally, the CDC estimates, based on antibody levels from commercial labs, that nearly 58% of Americans have been infected at least once.
Omicron variants, however, are known for their ability to evade immunity–especially BA.4 and BA.5, two relatively new subvariants thought to be the most transmissible so far, with documented ability to evade immunity both from vaccination and prior infections.
Levels of BA.4 and BA.5 are ticking up in the U.S., comprising 5% and 8% of infections as of two weeks ago, according to the CDC. New data will be released Tuesday.
While it’s unknown if the variants will dominate the U.S. as they did earlier this spring in South Africa, they’re already proving themselves as competitors against the currently dominant B.2.12.1, which comprised 62% of infections two weeks ago, and BA.1, which comprised 25%.
Additionally, while vaccines are known to reduce the risk of severe illness and death, they don’t prevent the spread of COVID–at least not fully. Breakthrough infections still occur, and “research is ongoing to understand the extent to which being vaccinated stops you from becoming infected and passing the virus on to others,” according to the World Health Organization.
Those who are fully vaccinated should continue to practice prevention measures like masking and social distancing to protect others, it adds.