Los Alamos National Laboratory scientists who have played key roles in modeling the COVID-19 pandemic for New Mexico are now using mathematical models and computational simulations to evaluate scenarios for vaccine distribution.

Using different variables, such as the vaccine efficacy, its dissemination to different workforce populations and other conditions such as school and business re-openings, the models can assess how COVID-19 will spread or stop spreading through communities.

"We're focusing on impacts of different priority groups," LANL epidemiologist Sara Del Valle says, who explains that the computational model can "stratify the workforce into different industries, so we can differentiate nurses from teachers from stay-at-home moms and/ or dads, so we can actually measure the impact on the overall population."

While a model for vaccine distribution has been in the works, Del Valle says scientists were waiting on data. "There was a lot of uncertainty in terms of the vaccine efficacy and the impact on healthcare…so we were kind of waiting to get a little more information on how effective the vaccine was going to be before we started. If we were going to have to explore the entire range of possible parameters, it was going to be time consuming and not very useful."

Fellow scientist Ben McMahon, who has been leading what he characterizes as a "broad" Department of Energy effort across national laboratories to provide predictive modeling, says that initiative has been grappling with "a wide variety of questions" for the last eight months and now "it's vaccine distribution's turn."

Indeed, with Pfizer's vaccine expected to become available in the US soon, with others to follow, distribution questions are now more than theoretical.

New Mexico placed its first orders for Pfizer's vaccine on Dec. 4, according to Matt Nerzig, a spokesman in the governor's office. In a statement, Nerzig says the federal government has allocated an initial 17,550 doses of Pfizer's vaccine from an initial national supply of 6.4 million doses. Pfizer has requested an emergency use authorization from the federal Food and Drug Administration; the earliest shipping date, if that request is granted, would be Dec. 15. The FDA is reportedly scheduled to discuss that request this Thursday, but published documents today showing the vaccine had high efficiency across demographics within 10 days of the first dose.

New Mexico's "initial doses will be provided to frontline healthcare workers who are under enormous stress and risk from being on the frontlines of the battle against COVID-19 for nine months and who now face the worst medical surge since the pandemic began," Nerzig said via email. "We will update the public as we further develop our distribution plans based on more details from the federal government about available doses and recommended uses for the Pfizer vaccine and Moderna's vaccine, the next candidate likely to receive Emergency Use Authorization consideration from the FDA in December."

Those plans will also involve LANL's input, Nerzig tells SFR: "Our ongoing collaboration with the modeling team at Los Alamos National Laboratory continues as we plan and refine the best ways to distribute the vaccine in a safe, equitable and effective way," he said via email. "From the start of the pandemic, we have made every effort to rely on the best possible data and analysis to fight the virus."

While the scientists are using models developed a decade ago at LANL—which have been used to model everything from influenza to bioterrorism— the parameter values have to be adjusted for COVID-19, the behavior of which has been "complex," Del Valle says.

One important data point, Del Valle says, is public willingness to be vaccinated. "We're using survey data that shows between 40% and 60% of the US population will be willing to get vaccinated. And so we'll see what happens if everyone gets vaccinated. Then we'll be able to mitigate the risk of spread faster, but if people are not willing to get vaccinated, that will obviously have ramifications into when we can reopen the economy safely."

Del Valle and McMahon also note that the LANL model has more granular detail than other types of distribution models "so you are able to better inform targeted intervention strategies," Del Valle says.

While both describe a COVID-19 vaccine as the "light at the end of the tunnel," the scientists emphasize the importance of continuing mitigation strategies.

"The fact that the vaccine is going to be available and is going to start working as we work our way through the spring should incentivize people to be extra vigilant and make sure we don't start a whole bunch of COVID infections that turn into another wave of infections when we could have just waited two months and things could have been might easier," McMahon says. "There's an end in sight. We all know it's painful to do all of these isolations and avoiding family gatherings, but…if we can delay things past springtime, there's a very real chance the problem will be much alleviated."

In other words, the vaccine won't immediately end the pandemic, Del Valle says. There will be limited doses, they will take time to work and it's important for people to not relax their precautionary measures in the meantime. That tendency to "relax their behavior" when case numbers have dropped has led to new waves of infection, such as what New Mexico recently experienced.

While daily case counts have been decreasing following a two-week "reset" of the strictest restrictions, hospitals across the state are grappling with overloads. But hospital leaders on Dec. 7 said they also are poised for the first doses of vaccines for their frontline workers.

Christus St. Vincent Regional Medical Center Chief Medical Officer Dr. David Gonzales says the hospital purchased a deep freezer— the Pfizer vaccine requires -70 degree Celsius temperatures—"and we have the capacity to hold quite a bit of the vaccine and we preparing in our plan. I think we'll have good participation from all of our associates and I'm hoping the vast majority say yes to the vaccine."

Hospital leaders from Lovelace, Presbyterian Medical and University of New Mexico Health Center yesterday also said they have arranged for storage as well.

Presbyterian Chief Patient Safety Officer and Medical Director of Infection Control Dr. Jeff Salvon-Harman described the possibility of the vaccine as "one ray of hope on the very near horizon…the 17,500 [doses] are the first step toward protecting our entire healthcare workforce…it doesn't mean they can let their guard down, but it becomes an added layer of protection to give them more confidence in a high risk environment."

As for the rest of the population, willingness to get vaccinated—and availability of the vaccine—will determine when we see some easing up of restrictions. Del Valle says next summer seems like a possibility. "However, it's all dependent on behavior; it's all dependent on willingness to get vaccinated. If can convince people to really get vaccinated, that would be fantastic."