George Washington University is one of the testing sites for the first coronavirus vaccine in the United States to move into the critical third phase of testing.

And doctors there are already learning a lot.

Developed by the National Institute of Health and Cambridge-based Moderna, the mRNA-1273 vaccine is now actively being injected into thousands of people (as well as placebos for comparison) to gauge effectiveness and side effects. This vaccine requires two injections, administered 28 days apart.

The vaccine and the testing of it are part of Operation Warp Speed, a public-private partnership aiming to deliver 300 million doses of effective and safe COVID-19 vaccine by early 2021.

Dr. David Diemert is the principal investigator for the study at the George Washington University site, one of about 90 such sites in the U.S. He appeared on the Kojo Nnamdi Show Tuesday to talk about the progress and what they’ve seen so far in terms of testing — namely no serious side effects and no mutations of the virus.

Diemert said that nationwide about 25,000 people have been injected with this vaccine, which includes nearly 250 people at GW. He said that the first volunteer was vaccinated on July 27th and some of the participants are ready for their second dose.

So far, side effects have been mild and mostly related to injection site reactions. This means some soreness, swelling at the injection site, and possible low-grade headaches. He said these symptoms don’t last more than a day or two. “Of all the people who have been vaccinated nationwide, about 25,000, there hasn’t been much more than that,” Diemert said. “There have been no serious side effects from the Moderna vaccine.”

It’s still way too early to tell anything about the effectiveness. Diemert said they will follow and test all who are getting either a vaccine or placebo injection to determine who ends up getting a “symptomatic COVID infection,” meaning they test positive and have symptoms.

So far, doctors are encouraged. Diemert says they have not yet seen the level of mutations of the coronavirus as might occur with other diseases or a parasite. That makes vaccine development potentially simpler and quicker. “In general, it’s much easier to develop a vaccine for viruses just because they’re much simpler organisms than, say, malaria, which is much more complex,” said Diemert.

An additional goal of the trials was to make sure that a diverse set of volunteers, including those who might be more at risk of becoming very sick from COVID-19. This includes older Americans, those with pre-existing conditions, and people of color.

Diemert was joined on the Kojo Nnamdi Show by Dr. Leana Wen also of the George Washington School of Public Health. She said that a long legacy of understandable mistrust of the medical community by communities of color could make this mission difficult.

“These are the same communities that, given the legacies of discrimination and experimentation, feel like they may be the subjects who are getting experimented on versus having something that is helping them in the community,” said Wen. “Trust can’t be built overnight.”

To this end, Diemert says that they’ve made major strides to reach these communities and says that nearly half of the volunteers at his site are either Latinx or African-American.

Trials remain ongoing and ensure that this critical phase will not be sped up or compressed in order to meet any timeline talked about, be it October or early 2021, Diemert says. What’s different than other vaccine trials, he adds, is that there are many sites across the country all doing testing at the same time in an attempt to protect against one particular virus.

The GW site has a few more weeks of enrollment and is still looking for more volunteers. People over the age of 18 are eligible, but they can’t be pregnant or breastfeeding, have a condition that impacts the immune system, and have already had COVID-19.

Diemert recommends those that are interested to go to the vaccine research unit website to sign up and for more information.