CNN News:美国扩大疫苗接种人群 不再保留第二剂疫苗

A cnn medical analyst says the United States might have passed the peak of new coronavirus cases. A few weeks ago, health officials said hospitalizations related to the disease were at about 132,000 per day. Now, these hospitalizations are down to 124,000 per day. So some improvement there.
But a former commissioner from the U.S. Food and Drug Administration says there's a new variant of COVID, a new strain of it that could cause another increase in coronavirus cases. He says the silver lining there is that a lot of people will have already been infected with the disease and will be immune to it, and a lot of others will be getting a new emergency vaccine.

This is how herd immunity is achieved. It's when most of a population becomes immune to a disease and it can happen in two main ways, either enough people have recovered from the illness and developed immunity naturally, or a drug like a vaccine prevents people from getting sick in the first place. Scientists don't know yet if the two approved vaccines work against the new COVID variant.
There's also been some confusion about whether the second doses will be available. Drugmakers say each of the approved vaccines requires two shots given a few weeks apart to be fully effective, and because the government released all of its available doses to try to give as many people as possible their first shot, it's not clear if the second dose will be available to everyone on time.
The Trump administration says it's confident that ongoing vaccine production will keep up with demand.