The U.S. now has three COVID-19 vaccines, and public health officials are quick — and careful — to say there’s no bad option. But their effectiveness, manufacturing and distribution vary.Why it matters: Any of the authorized vaccines are much better than no vaccine, especially for people at high risk of severe coronavirus infections. But their differences may fuel perceptions of inequity, and raise legitimate questions about the best way to use each one. Stay on top of the latest market trends and economic insights with Axios Markets. Subscribe for freeThe big picture: Under the threat of new variants, vaccinating as many people as fast as possible is key to controlling the outbreak in the U.S. Public health experts are generally united in saying that Americans should get whichever vaccine they are offered first.All three vaccines authorized for use in the U.S. — from Moderna, Pfizer and BioNTech, and Johnson & Johnson — registered a very high efficacy in preventing hospitalization and death from COVID-19.“The efficacy against severe disease [is] greater than 85%, and there have been no hospitalization or deaths in multiple countries, even in countries that have the variants,” NIAID Director Anthony Fauci said of the Johnson & Johnson shot this weekend on ABC’s “This Week.” “Be careful when you try to parse this percent versus that.”It is difficult to compare the vaccines head-to-head based on existing clinical trial data, but there are key differences.The most obvious is the dosing. J&J requires only one shot, although a second booster dose is being tested. Pfizer and Moderna’s vaccines require two doses, a few weeks apart. Pfizer and Moderna’s vaccines have, so far, been more effective than the J&J vaccine in clinical trials at preventing any symptomatic disease. Some experts quickly point out that the vaccines weren’t compared directly against one another, so the differences may be on paper only.But on paper, those differences appear significant: The Pfizer and Moderna vaccines offer protection of more than 90%, while J&J’s efficacy against symptomatic disease is 66%. On the other hand, some people may prefer J&J’s one-and-done approach. It appears to offer protection against a variant that originated in South Africa. The Pfizer and Moderna vaccines appear to be less effective against this variant, though it is unclear how much less effective and the companies are studying it.J&J is also cheaper and easier to ship than the other two shots.Yes, but: Whether the vaccines are equally as good or not, the efficacy numbers are already fueling the perception of a two-tiered vaccine system, the Washington Post reports.“J&J is going to be a challenge for all of us,” Washington Gov. Jay Inslee told WaPo in an interview.And if the J&J vaccine is heavily used in communities of color, which have already borne the brunt of the pandemic, trust could be further eroded.“If we end up with a hierarchy that says all rich White people get Pfizer, and all poor Black people get J&J, that would be a problem,” Helene Gayle, president and chief executive of the Chicago Community Trust, told the Post.What they’re saying: “The whole thing is awkward. Everyone is treading on eggshells, because we want to get the right message across,” said John Moore, a Professor of Microbiology and Immunology at Cornell University. “The nuances are very hard because we don’t have concrete answers to every question.”In an ideal world, it may make sense to give the J&J vaccine to younger people, he said, because that would potentially lower the risk of resistant variants emerging. “The problem is, we don’t really have the luxury of time or of doing all the clinical trials you’d like to see done.”What we’re watching: "Trying to convince people that the vaccines are all equal isn’t going to work. People are making claims that go beyond the solid data we have, and that’s a risky proposition. We’re going to see the differences in rates of adverse events, for example, pretty quickly for ourselves once we know lots of people getting vaccinated," clinical-trial expert Hilda Bastian told Vox."Especially when the fear of major outbreaks subsides — prematurely — and we’re trying to get younger people to accept vaccination, adverse reactions are going to matter to people."The bottom line: “The worst option is no vaccine. And in the end, any of these approved vaccines is better than no vaccine, and that’s absolutely solid,” Moore said.Like this article? Get more from Axios and subscribe to Axios Markets for free.