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UNLV School of Medicine conducts COVID-19 drive-through testing on Wednesday, May 13, 2020. (Jeff Scheid/The Nevada Independent)
Last updated: December 10th, 2020 - 3:15pm

A U.S. Food and Drug Administration advisory committee made a positive recommendation at a hearing on Thursday for the approval of one of the two leading vaccines for COVID-19, but in addition to the vaccine’s safety and effectiveness concerns, experts in Nevada are faced with determining how they will get approved doses to the people who need them.

For Dr. Trudy Larson, dean of the School of Community Health Sciences at UNR and a member of the state’s COVID-19 medical advisory team, this means looking at creative solutions that expand the workforce and maximize the speed at which vaccines can be administered in the state’s rural areas.

“The smaller facilities will not have enough people to be able to do that… Part of the consideration is special vans, maybe strike teams that can go out with those vans to get the vaccine distributed as efficiently and effectively as possible,” she said. “We do not want any wasted doses. This is really a big deal.”

Authorization by the FDA based on the panel’s recommendation would mean a record-breaking development and approval timeline for manufacturer Pfizer Inc. and allow for mass vaccinations in the U.S. against a virus that has caused more than 285,000 deaths nationwide — including more than 2,300 in Nevada — and wracked the state economy.

The FDA released a report on Tuesday on the Pfizer vaccine saying it “met the prescribed success criteria” in its clinical study. The company has reported efficacy rates of 95 percent, and, if authorized on Thursday, the vaccine could be distributed as early as this weekend.

The Moderna vaccine is likely not far behind with an authorization hearing scheduled for Dec. 17.

Nevada’s vaccine distribution plan includes a list of tiers of individuals who will receive the first doses of the vaccinations as they become available. Under the plan, health care workers, Department of Corrections staff, law enforcement and public safety officials will be first.

However, just as important as determining who will get the vaccinations is how vaccine doses will get to the appropriate locations, and the new technologies used for both new vaccines in development, particularly the Pfizer vaccine, pose challenges when it comes to storage.

The science

The Pfizer and Moderna vaccines are unique in the world of vaccinations, developed through methods that no other approved vaccine has previously utilized. However, according to Dr. Jeffrey Ebersole, a professor of biomedical sciences at UNLV, these methods have been the subject of extensive research for more than a decade.

“Most of the public is aware and has had different types of shots … And they’re each slightly different,” Ebersole said. “The Pfizer and Moderna vaccines… are different, and we don’t have any current human vaccines that are like this.”

The development process for some vaccines, such as the Measles, Mumps, and Rubella (MMR) vaccines, utilize an attenuated, or weakened, sample of a live virus. For others, such as the flu vaccine, a dead sample of the virus is used. However, the Pfizer and Moderna vaccines are different, and do not use living or dead samples of the virus.

Instead, both utilize the genetic material, RNA and DNA, found within the coronavirus and that code the virus’s spike protein. The protein is what allows the virus to attach to human cells and spread infection. When the genetic material of the protein is introduced to the body, the body is able to create the protein piece, recognize it does not belong, and make antibodies in response.

While there are other vaccines in development using genetic material, Ebersole noted that the other leading manufacturers have not used this new method for development. The Oxford/AstraZeneca vaccine, which released trial data on Tuesday indicating it is safe and 70 percent effective, was developed through a method which involves putting part of the genome of the coronavirus into another type of virus.

A decade of testing and developing the DNA and RNA based development methods, with a focus on previous coronavirus outbreaks (SARS and MERS), helped Pfizer and Moderna make their way to the front of the vaccine pack, said Ebersole.

Distribution challenges

The Pfizer vaccine requires storage at a constant, ultra-cold temperature, - 70 Celsius, meaning that states must have specialized freezers for both storage and transportation. While the Moderna vaccine does not require temperatures quite as low, it still needs to be kept frozen at - 20 Celsius.

A review of state plans in early November by ProPublica found that most state officials were not prepared to deal with that requirement. Larson said that Nevada will likely face most of its distribution challenges in rural areas because they do not have the same access to -70 freezers as hospitals and pharmacies near the state’s two urban centers. 

The state plan for rural areas includes quick distribution in vans loaded with dry ice, which has a temperature of approximately -78 Celsius, as well as potentially sending out “strike teams” of additional qualified vaccinators to distribute doses at a higher rate.

Additional vaccinators will be necessary to meet demand not just in rural communities but also throughout the state, according to Larson. Pharmacists will be a major component of the process, she said, but she also thinks it’s possible the state will look at calling on other health care providers, such as dentists and veterinarians who have experience administering vaccines, to assist.

“They know how to give shots,” she said. “I think that is within their scope of work, it just has to be adapted a little bit.”

It is likely as well that medical students will be called on to help with the parts of the vaccination process that don’t involve actual injection and administration of the vaccine, said Larson.

To further add to distribution complications, both the Pfizer and Moderna vaccinations require two doses of the vaccine to be administered in order to be as effective as trial results have shown. For the Pfizer vaccine, the second dose is administered 21 days later, and for the Moderna vaccine it’s administered after 28 days.

“So basically, if we get 40,000 doses, that’s 20,000 people,” Larson said. 

The state’s emergency plan for vaccine distribution was first developed in response to the 2009 H1N1 pandemic, according to Larson, with new adaptations for mask guidelines and social distancing requirements.

“That’s when there was a very big push for every piece of the country to have a pandemic plan laid out,” she said. “It just required a few extra little tweaks.”

Some of those tweaks involve creating vaccination centers where social distancing is possible. One of the state’s responses to this requirement is drive-through vaccinations, which Larson says will begin in Washoe County.

Effectiveness

Pfizer and Moderna have both been touting higher-than-expected effectiveness rates for their vaccines — between 90 and 95 percent. However, those rates might be slightly lower once the vaccines are distributed to a larger, more diverse population.

The FDA’s study of the vaccines did find that they remained effective regardless of race, weight and age differences.

“All of a sudden, you’re bringing in a much broader heterogeneity of your population, different genetics, different behaviors, different environmental exposures that could and will likely change the effectiveness of it,” Ebersole said.

On Thursday, members of Pfizer’s team said that the organization made an effort to include ethnically and racially diverse subjects in its trials from the start. Effectiveness would likely not drop below the 75 percent mark that historically other viral vaccines have hit, even when applied to this larger population, though, Ebersole said.

Even if it does not maintain its initial effectiveness rates, Ebersole emphasized the importance of the vaccine as a measure not only to protect the vaccinated individual but to protect the larger community.

Because neither vaccine contains the virus itself, they cannot cause infection. However, neither of the vaccines has yet been proven to prevent infection, either — only to prevent symptoms.

This means that vaccinations may not prevent people from being infected by the virus, but it has been shown to prevent people from getting sick and then experiencing life-threatening symptoms, according to Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases and member of the White House Coronavirus Task Force.

“That’s a bigger question anyway,” Larson said. “We’re going to have to go and culture people serially and find out if they get it, you know, even though they’re vaccinated.”

Testifying before the advisory panel on Thursday, Dr. Kathrin Jansen, the head of vaccine research and development at Pfizer, said researchers are looking into closer study of the impact of the vaccine on infections. She also mentioned that in non-human trials, the vaccine was observed to limit infection and transmission.

Even though that question has not yet been answered, Larson says that herd immunity should be a driving factor for individuals to get the vaccine as it is possible people will be protected from infection and could, therefore, protect others who are still susceptible.

Although the effectiveness of the vaccine at preventing infection and not just illness is still unknown, there is a chance it will be able to do both. If it does not, vaccines may still help to protect against the spread of infection by allowing vaccinated individuals to "shed fewer viruses."

“I would hypothesize that the vaccine will cause a reduction in the virus (and thus reduce infectiousness) but that will be studied this next year so that we have good scientific information,” Larson said.

Both Ebersole and Larson agreed that sufficient immunity in the population to stop transmission and reduce the impact of COVID-19 on society is more than 70 percent. Once more than 70 percent of the population is vaccinated, Larson said, things can start going back to normal and mask and social distancing measures can be relaxed.

Hesitancy

Distribution challenges are not the only hurdles the country faces in hitting that benchmark — vaccine hesitancy has been an increasing problem in the U.S.

In September, a Kaiser Family Foundation poll found that 62 percent of Americans were concerned that “political pressure” may lead the FDA to rush approval on a vaccine without making sure it is safe and effective. That same month, the Pew Research Center found that 49 percent of U.S. adults said they would not get a vaccine for COVID-19 if it was released at the time.

Ebersole expressed concern that part of the cause for skepticism was the pace at which the vaccines were developed under Operation Warp Speed, a federal initiative aimed at accelerating development, manufacturing and distribution. For those worried that the quick development process means the vaccines were “rushed,” Ebersole said they were both subject to all of the same testing and approval processes that any immunization would be. 

He also noted that part of what allowed for speedy vaccine development was the decade of lab research spent on the new method prior to the coronavirus outbreak. Typically, a vaccine takes years to develop; the Mumps vaccine, previously the fastest to be developed, took four years.

“The speed and effectiveness of which vaccines are generated is really determined by the need, and the need here was so great and so global that it put everybody into high gear to do this,” he said.

For those concerned about safety, Ebersole pointed out that the two vaccines contain only a small portion of nucleic acid from the virus, rather than a sample of the virus itself, meaning it is not possible to contract an infection from the vaccine.

Nevada has also collaborated with other Western states on an additional review of any vaccines approved by the FDA through a COVID-19 Scientific Safety Review Workgroup.

However, those who are vaccinated should be aware of potential symptoms while protections from the vaccine develop, including aches, soreness and a slight fever, said Larson. 

Larson also pointed out that because the vaccines prevent illness and not infection, it is only one step in addressing the pandemic, albeit an important one.

“It’s about being patriotic, actually,” Larson said. “And maintaining our country the way we want it to be, and not running scared, but being able to stop, set our feet in the ground, get our vaccine, and say, ‘Okay, now we’re ready, and we can move forward.’”

Through a combination of mask wearing, continued social distancing and mass vaccinations, Larson believes the country could reach its immunity benchmark and begin returning to somewhat-normal by next fall. 

Lasting effects from this pandemic will continue to affect outbreak responses at individual and government levels, according to Larson, with measures such as masks, hand washing, and distancing in place more often when people are sick or when a virus is spreading. However, she says, these measures will be less necessary for the general public in the future if action is taken now.

“I want us to feel like we are really able to conquer this virus in a logical fashion,” Larson said. “This is not about dreaming. This is not about a miracle. This is really hard work that I think we need to do, that everybody makes it their duty so that we can protect people.”

This story was updated at 3:15 p.m. on Thursday, Dec. 10 to reflect the positive recommendation made by the FDA advisory committee.

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