UCHealth University of Colorado Hospital will soon enroll patients in the first large-scale U.S. clinical trial of a coronavirus vaccine.
The phase 3 study of Moderna’s experimental vaccine will include 1,000 people at University of Colorado Hospital on the Anschutz Medical Campus. In addition, another 30,000 patients nationwide will participate in the trial, which is slated to start this summer, says Dr. Thomas Campbell, a University of Colorado School of Medicine and UCHealth virologist and infectious-disease specialist.
Campbell’s team will internally recruit UCHealth patients, staff and providers based on a hierarchy of criteria, he says. Those in high-risk occupations such as essential workers in crowded facilities, people living in residential facilities and high-risk health care workers will be first up, Campbell says. People at risk of becoming seriously ill with COVID-19, including seniors and those with medical problems such as diabetes, obesity, heart disease, lung disease, and chronic kidney disease, will also be a priority, he says.
The UCHealth team will also invite individuals in higher-risk groups to participate in the study including Black, Indigenous and Hispanic patients.
After identifying possible trial participants, representatives from UCHealth will contact the patients and staff members through My Health Connection to invite them to participate, if interested.
“The emphasis is on demonstrating the efficacy of the vaccine in people who are at most risk of getting COVID-19,” Campbell said.
The phases of Moderna coronavirus vaccine trials
The trial will involve an initial injection and a booster 28 days later. It’s not a challenge trial: that is, patients will not be exposed intentionally to the virus that causes COVID-19. The huge number of participants, though, will allow the study’s leaders to compare the number and severity of coronavirus infections among those who got the vaccine with those who did not. Campbell says his team intends to move quickly and have all 1,000 patients injected with a first dose within eight weeks – and many would have received the booster by then also.
The study will follow patients for two years. That doesn’t mean a commercial vaccine must wait until 2022. In a best-case scenario, compelling preliminary results could bring speedy approval from the U.S. Food and Drug Administration (FDA). Were that to happen, widespread vaccination of the general public could roll out by next spring, Campbell says.
The FDA requires three phases of human clinical trials before it approves a drug (that’s in addition to having shown that the drug works in petri dishes, mice, and other animals). Phase 1 involves tens of people to make sure the drug is safe. Phase 2 generally involves hundreds of people and focuses on safety as well as what doses seem to work best. Phase 3 typically involves thousands of people and is used to prove safety and effectiveness.
Clinical trials normally proceed in sequential order over several years. These are not normal times. The phase 3 trial is launching with Moderna’s phase 1 trial data soon to be published and the phase 2 trial having just launched in late May. But the initial findings have been promising enough – and the desperation for a means of attaining COVID-19 herd immunity without swamping hospitals great enough – that the pace of science is being pushed to its very limits.
How Moderna coronavirus vaccine trial in Colorado works
For the time being, Moderna calls its experimental vaccine mRNA-1273. It’s one of perhaps 140 vaccine candidates under development. As of June 29, those included 11 in phase 1 testing, eight in phase 2 testing, and three in phase 3 testing. One has been approved: the CanSino Biologics vaccine, which the China’s Central Military Commission approved on June 25 for immunizing the country’s military personnel. That vaccine, similar to the one being developed by the University of Oxford and AstraZeneca, uses modified adenoviruses – viruses that typically cause the common cold – to inject genetic material into human cells.
Viruses exist to inject genetic material into living cells. They do so with the dark intent (if a submicroscopic living-dead bundle of molecules can have intent) of hijacking cellular machinery to produce copies of the viruses themselves. In the case of the CanSino Biologics and Oxford-AstraZeneca vaccines, the adenovirus genetic material hijacks cells to produce copies not of themselves, but rather of the spike proteins that protrude from the fatty sphere of the SARS-CoV-2 virus that causes COVID-19. The body’s immune system then recognizes the harmless, unmoored spike proteins as invaders and makes antibodies to recognize them. If actual coronaviruses later appear, those antibodies glom onto the viruses’ spike proteins, and the immune system, forewarned, takes those viruses out. At least that’s the idea.
That’s also the idea with the Moderna coronavirus vaccine. The big difference is that Moderna’s vaccine does away with the modified adenoviruses as a delivery system. Instead, the Moderna vaccine packs its spike-protein-recipe genetic material – in this case messenger RNA (mRNA) – into nanoscale fatty globs that cells absorb.
After the injection, Campbell says, “once that RNA molecule is within muscle cells, those muscle cells start to make the coronavirus spike protein, which our body recognizes as a foreign protein, and then produces an immune response.”
Controlling the coronavirus pandemic through vaccines
Vaccination using mRNA or DNA molecules, should it prove effective, would be pathbreaking, Campbell adds.
“If it works for the coronavirus, it will not only be a significant step forward for controlling the coronavirus pandemic, but it will also be a proof that this strategy can work and be implemented in practice,” he said. “The advantage of using the mRNA approach is that it can be scaled up very rapidly. It’s much easier to make mRNA molecules in large quantities than it is to make purified viral proteins, or inactivated viruses, or virus-like particles.”
While the use of adenovirus to inject genetic material for a vaccine has been in the works longer than mRNA technologies, it’s also new. No human vaccine using adenoviruses has yet been approved (though a rabies vaccine for animals has).
If these or other emerging vaccines work, “It could be a real game-changer for the pandemic,” Campbell said. He cautioned, though, that most vaccine candidates ultimately fail – something we must be prepared to face with coronavirus vaccines being developed at warp speed. But with the abundance of brainpower and money pouring into coronavirus vaccine development, he’s optimistic.
“I’m elated by the pace of progress. It’s unheard of for any viral infection to have a vaccine progress at this rate. It’s really a great testament to how much can be done when people put their minds to something and work together,” Campbell said. “Wherever this will take us from here, and whatever our chances of success are, I’m certainly hopeful.”
To read UCHealth’s press release, click here.