You can gather indoors with unvaccinated people from one other household (for example, visiting with relatives who all live together) without masks, unless any of those people or anyone they live with has an increased risk for severe illness from COVID-19.

If you’ve been around someone who has COVID-19, you do not need to stay away from others or get tested unless you have symptoms.

簡單說,以目前疫苗(這裡指揮瑞默德納和嬌生)施打之後的研究(英美和以色列)發現COVID-19疫苗在不同年齡，種族以及患有慢性疾病的成年人中有效。即使接種疫苗的人確實受到感染，他們患嚴重疾病，住院或死亡的可能性也要小得多。

此外，初步但迅速增加的證據表明，完整接種完疫苗的人傳播給未接種疫苗的人的風險很小。(美國,英國,和以色列)

而以色列的研究更表明，輝瑞COVID-19疫苗對無症狀感染的有效率為90％，而接種COVID-19疫苗的人被感染後的病毒量大大低於未接種者。(病毒量是目前確知傳染最重要的因素)

所以CDC已經修正了一些規範...

COVID-19 and Your Health

是的