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Early results from clinical trials have shown that vaccines may be nearly 95% effective in preventing the transimission of COVID-19.

An independent safety and data monitoring board reported today that early results from the Moderna Phase 3 clinical trials show the company’s vaccine was 94.5% effective.

That news followed equally positive preliminary results on Nov. 9 from Pfizer showing that the coronavirus vaccine that Pfizer developed with German drugmaker BioNTech looks to be safe and more than 90% effective in preventing COVID-19 transmission.

While Phase 3 trials continue, Moderna and Pfizer are expected to ask the U.S. Food and Drug Administration for emergency approval for their new vaccines later in the coming weeks. Experts predict that approval could come in mid-to-late December.

Pfizer expects to have 50 million doses ready to administer by the end of the year. Given that the vaccine involves a booster shot at the 28-day mark, those doses could protect 25 million people. The company says it aims to produce another 1.3 billion doses in 2021.

Moderna expects to have about 20 million doses of their vaccine ready to ship within the U.S. by year’s end and plans to manufacture and ship about 500 million to 1 billion doses globally in 2021. The Moderna vaccine also requires a booster shot.

Coronavirus vaccine trials

The news from Moderna and Pfizer bodes well for the beginning the end of the COVID-19 pandemic and for other coronavirus vaccines. Two of them – the Moderna and Oxford/AstraZeneca vaccine – are in late-stage clinical trials at UCHealth.

“I think that these early results are very exciting – they demonstrate very high efficacy in the short term, and the results in the Moderna study are very consistent with the results of the Pfizer study we heard about last week,” said Dr. Thomas Campbell, the University of Colorado School of Medicine and UCHealth virologist and infectious-disease specialist who leads the Moderna trial at UCHealth. “So we have two independent scientific experiments that are analyzing two very similar vaccine strategies that give us very high confidence that these results are real.”

Campbell added, though, that the Moderna trial happening at UCHealth University of Colorado Hospital on the Anschutz Medical Campus and 88 other sites will run for a total of two years.

“It’s important to continue, because we need to know both longer-term safety and efficacy,” he said.

‘Good immunity’ in studied coronavirus vaccines

The similarity between the Moderna and Pfizer vaccines also should extend to the Oxford/AstraZeneca COVID-19 vaccine, says Dr. Gary Luckasen, who is leading the Oxford/AstraZeneca vaccine trial at UCHealth’s northern Colorado hospitals.

Both the Moderna and Oxford/AstraZeneca COVID-19 vaccines introduce SARS-CoV-2 (the virus that causes COVID-19) spike proteins to the body just as Pfizer’s vaccine does. But rather than inject SARS-CoV-2 spike proteins directly, the vaccines deliver genetic instructions (via messenger RNA, or mRNA) that make their way into shoulder-muscle cells near the injection site. The Pfizer and Moderna vaccines deliver the genetic instructions to muscle cells in tiny fatty envelopes; the Oxford/AstraZeneca vaccine does so using a weakened common-cold virus called an adenovirus. Once in the muscle cells, the mRNA instructs those cells to produce SARS-CoV-2 spike proteins that then trigger the immune response. (For background on coronavirus vaccines, check out UCHealth’s vaccine Q&A).

Given the parallels in approach, there’s reason to anticipate good results from the Oxford/AstraZeneca trial, Luckasen says.

“Since the basic protein we’re developing immunity to is similar to what we see with the Pfizer and Moderna vaccines, this should be a vaccine that’s not only well tolerated, but also produces a good amount of immunity,” he said.

The Oxford/AstraZeneca trial aims to enroll 1,500 patients at UCHealth Medical Center of the Rockies in Loveland in conjunction with UCHealth Poudre Valley Hospital in Fort Collins, UCHealth Greeley Hospital, and UCHealth Longs Peak Hospital in Longmont. Luckasen’s team has enrolled about 300 so far and are adding another 70 or so participants a day, six days a week, Luckasen says.

The Moderna trial at UCHealth has enrolled 217 – a number that’s now capped, Campbell says, because the overall trial is fully enrolled. Some participants still need their booster, which, like the Oxford/AstraZeneca vaccine, happens at the four-week mark.

Mobilization ahead

Taken together, the COVID-19 vaccines indeed look promising – and another eight coronavirus vaccines are in late-stage trials around the world, along with dozens of others in earlier human and animal trials. Assuming some or all 11 of that early pack pan out, UCHealth and the rest of the health care system face a big challenge: distributing, administering, and tracking the vaccinations of billions of people around the world. Experts estimate that, assuming no surprises, the general public will be in line for COVID-19 vaccination late in the second quarter or early in the third quarter of 2021 (this assumes that health care workers, essential workers, and those at high risk for serious disease are vaccinated earlier).

The biggest hurdle facing the widespread distribution of the Pfizer COVID-19 vaccine will be that it must be stored at minus-94 degrees Fahrenheit. Your standard kitchen freezer chills at about zero Fahrenheit. That’s the difference between a cold winter night and a hot summer day, and one that demands specialized ultra-cold freezers. Once thawed out, the Pfizer COVID-19 vaccine keeps for about five days in a refrigerator. The system ensuring that vaccines maintain safe temperature from manufacture to injection is known as the cold chain.

Nancy Stolpman, UCHealth’s Director of Pharmacy, said UCHealth has done a full assessment of its cold-chain storage capacity across the system. While more ultra-cold freezers will clearly be needed, it’s still unclear how many, she says.

That’s because much remains uncertain. Will Pfizer, the state, counties, or others have storage capacity? How much of the Pfizer vaccine will be available and when? When might the Moderna, Oxford/AstraZeneca, or other COVID-19 vaccines become available?

That’s a key question because the Moderna vaccine and Oxford/AstraZeneca vaccines will be easier on the cold chain storage. They can be stored and shipped at minus-4 degrees Fahrenheit, a temperature that standard freezers can manage. Also other vaccines in development, including ones from Johnson & Johnson and Novavax, can be stored and shipped above freezing at standard-refrigerator temperatures.

Other wrinkles: Pfizer plans to ship the COVID-19 vaccine in multidose vials, meaning UCHealth must take care to have patients lined up promptly once a vial comes out of deep freeze. UCHealth facilities in Greeley, Steamboat Springs, and Colorado Springs will store COVID-19 vaccine caches for the state (and not just UCHealth). Given the need for a booster, UCHealth must ensure that, once a patient receives the initial dose, the booster’s availability three or four weeks out is guaranteed. That will take good record keeping, which UCHealth’s Epic electronic medical record will help manage, Stolpman says. That recordkeeping will extend to reporting to the Colorado Immunization Information System, she adds.

A team of 30 people from across UCHealth – pharmacists, infectious-diseases experts, hospital administrators, clinicians and others – is working through the many aspects of what will, if all goes well on the vaccine-development front, be a true vaccination mobilization. It’s a lot of work amid great uncertainty, Stolpman says, but it’s a great problem to have during a pandemic.

“This is fabulous,” she said. “We appreciate the challenge. We’re welcoming it. We want it.”

For information about enrollment or questions about UCHealth’s Oxford/AstraZeneca vaccine trial at UCHealth’s hospitals in northern Colorado, call 970-624-1589 or email [email protected].