With the second COVID-19 drug from Moderna on its way to emergency use authorization by the Food and Drug Administration, we may shortly have a choice of two vaccines, including the recently approved candidate from Pfizer. Experts say that both have an efficacy rate of around 95% after the two prescribed doses, and new data found that the Moderna vaccine begins preventing infections after the first shot.

“Both the Pfizer and Moderna vaccines demonstrate some immunity after the first shot, but both shots are required to achieve the high rates of efficacy,” Dr. Kavita Patel, a primary care physician in Washington D.C. and a leading expert in health care reform, told Yahoo! News. Patel said both vaccines also had similar side effects with no major adverse reactions noted. The expert said because of the urgency of the COVID-19 pandemic and the amount of vaccine required inoculate nationwide, Americans probably won’t have a choice as to which vaccine they receive.

“It’s highly unlikely that you will have the luxury of making choices, because you can imagine that if there is a vaccine with a high rate of promise, everybody is going to want one.”

According to The Hill, a comprehensive report outlining the “efficient manufacturing, financing, and distribution of a COVID-19 vaccine,” found that given the recommendation of two doses per person we’ll need 462 million doses to achieve herd immunity and 660 million doses for the entire U.S. population.

A recent Pew Research Center poll revealed that 60% of Americans say they would definitely get the COVID-19 vaccine, up from 51% who said this in September. Public confidence has also grown with 75% of American polled saying that research and development will provide a safe and effective vaccine.