To find out if they work, they need volunteers.
Carla Garcia is one of them.
Before any vaccines got government authorization, Carla was one of the first in Southern California to volunteer for the AstraZeneca - University of Oxford vaccine trial.
"The reason why it's important for me to participate is because there's not a lot of information that comes out from trials via clinical or otherwise regarding Black people," she said.
COVID-19 affects African Americans, Latinos and other ethnic groups disproportionately. But surveys show vaccine hesitancy is highest in these groups.
"There has to be some engagement from the Black population, Latino population, and other minority cultures in the process itself, in order for us to be able to gain the same advantages from the results."
AstraZeneca's approach is already used in the pneumonia and shingles vaccines. Researchers modified a common cold virus to transport COVID-19 genetic material into the body. Early phase three trials show AstraZeneca's vaccine demonstrated 90% effectiveness in those given a low dose followed by a standard dose.
"Just like a flu shot there was soreness to the arm the next day. It felt very similar to that."
To vaccinate 70-80% of Americans, many more companies need to produce vaccines. Others in the pipeline include Johnson and Johnson, Sanofi and Novavax.
"With everything going on. It's important for us to see where we can have the impact, and where we can actually make a difference."
With case and death rates on the rise, Carla - who works at a plasma donation center - worries for her colleagues in health care.
"It's a tragedy, to see where we have come to in terms of just the sheer numbers of the people that are ill."
Carla hopes her example will encourage more minorities to participate.
More information about vaccine trials is available from the U.S. National Institutes of Health COVID-19 Prevention Network.
Correction: An earlier version of this story had incorrect information regarding the doses required for 90% effectiveness in AstraZeneca's vaccine. This has since been corrected in the story above.