The CDC is Preparing for Covid-19 Vaccines A and B. Here’s What You Need to Know

That’s not the case with Covid-19. So far, over 25.7 million people have been infected worldwide and 857,920 have died. With the prospect of many more infections ahead, the rapid deployment of a safe and effective vaccine is all the more urgent.

When might the first vaccines be distributed?

The Centers for Disease Control and Prevention told public health agencies last week that limited doses of a vaccine may be available beginning in late October or November, although that would only be if a vaccine is shown to be safe and effective. According to the documents the agency sent to the public health offices, two million doses of what the C.D.C. labeled Vaccine A — most likely the Pfizer vaccine — may be available by the end of October, with 10 to 20 million doses possibly available by November, and 20 to 30 million by the end of December.

The C.D.C. said the other potential vaccine, Vaccine B — which matches the details of the Moderna vaccine — could have about 1 million doses available by October, 10 million by November, and 15 million by December. Each of the vaccines would require two doses to be effective.

Pfizer and Moderna did not respond to questions about the C.D.C.’s recent guidelines.

Who will get it first?

In the documents sent to public health agencies, the C.D.C. said certain groups would have priority, beginning with health care workers, essential workers (like police officers or those who work in critical industries like food production), “national security populations,” and workers and residents of long-term care facilities like nursing homes.

Those priority groups include millions of people. At a meeting last week of the Advisory Committee on Immunization Practices of the C.D.C., an agency official presented a slide showing that in the United States, there are about 17 to 20 million health care workers, 60 to 80 million essential workers and about 53 million people older than 65.

On Wednesday, the National Academies of Sciences, Engineering and Medicine unveiled a 114-page plan, sponsored by the C.D.C. and the National Institutes of Health, that proposed a complicated four-phase system for priority.

Will these two Covid-19 vaccines be the only ones available?

Probably not. Aside from Moderna and Pfizer, there are 34 other vaccines in clinical trials worldwide. There are over 90 more vaccines confirmed to be in active preclinical testing. Over the next year, 69 of them are slated to go into clinical trials.