ZURICH/LONDON (Reuters) - With COVID-19 vaccine trial results looking positive, governments and pharmaceutical firms face their next daunting challenge: convincing the world to get inoculated.

Public resistance to vaccines has been much discussed this year, but the issue became very real on Monday when Pfizer and BioNTech announced their candidate was more than 90% effective in large trials - hoisting an actual shot onto the horizon.

President Donald Trump has often touted the role of the military in distributing a COVID-19 vaccine, but health officials close to the process who are concerned about public distrust are taking pains to say the federal government won’t actually be handling vaccines. 

The president said at the final presidential debate that the distribution of a vaccine would be swift because he’s “counting on the military.” 

“We have our generals lined up, one in particular that’s the head of logistics. … He’s ready to go,” Trump said Oct. 22.

Black Americans distrust the government so much they're not participating in large numbers in COVID-19 clinical trials, and many say they won't get a COVID-19 vaccine – at least not until many others get it.

Although the first two large clinical trials of candidate vaccines have managed to include about 3,000 Black participants each, it hasn't been easy. And later trials might have even more trouble. 

The Reagan-Udall Foundation for the FDA has received funding from The Rockefeller Foundation to support the COVID-19 Diagnostics Evidence Accelerator launched earlier this year in collaboration with Friends of Cancer Research. As a science-driven philanthropy focused on building collaborative relationships with partners and grantees, The Rockefeller Foundation seeks to inspire and foster large-scale human impact that promotes the well-being of humanity throughout the world by identifying and accelerating breakthrough solutions, ideas, and conversations.

Extraordinary and unusual measures may be needed to rapidly develop and distribute a vaccine against SARS-CoV-2, but those efforts should not compromise the safety and efficacy of any product that reaches the market, according to the FDA Vaccines and Related Biological Products Advisory Committee.

However, the committee did not make any recommendations for ensuring the products are not compromised.