The news is encouraging.
Two pharmaceutical companies and one biotech company report more than 90% effectiveness in clinical trials involving coronavirus vaccines, and they may be publicly available soon.
But it takes time to produce these vaccines, and supplies will be initially limited. So, as these companies prepare for emergency authorization from the Food and Drug Administration, important decisions must be made on who should be vaccinated first. And second. And so forth.
It might seem obvious that health workers and those most endangered by COVID-19 – older people in nursing homes with underlying health issues – should be the first.
But beyond those priority populations, it becomes less clear.
Mathematics and Modeling
Figuring out how to allocate vaccines is “a very complex problem,” Eva Lee, director of the Center for Operations Research in Medicine and Health Care at the Georgia Institute of Technology, told the digital science magazine Undark.
Determining the order in which groups should receive the vaccine depends on what kinds of priorities we make. As the Undark article points out, the question is this: Do we mostly want to prevent deaths? Or is the priority to slow transmissions?
If we want to prevent deaths, then the first vaccines should go to the over-65 “at risk” population. But if we want to slow transmissions, maybe primary recipients should be the biggest spreaders: young adults.
Mathematicians have been busy developing models for vaccine rollouts that consider age-based factors like these. But there are many others that can determine the most effective targeting of who might be next in line for vaccines: housing and socioeconomic status, local infection and transmission rates, even ZIP codes.
So, Who Decides?
The group that determines the order of vaccination is the Center for Disease Control’s Advisory Committee on Immunization Practices. The ACIP is a group of medical and public-health professionals, and on Nov. 23 it released a set of four “ethical principles” to guide the first allocations of COVID-19 vaccines.
ACIP said the priorities will be providing the vaccine first for health-care workers and those most at risk and ensuring that everyone, regardless of their socioeconomic status, will ultimately have access to vaccines.
More specifically, ACIP will be working from a distribution plan announced in October by a federal panel, the National Academies of Sciences, Engineering, and Medicine.
That plan identified four phases of distribution:
- Front-line health workers, EMTs, first responders, people at risk with underlying health conditions or with two or more chronic conditions, and people age 65 and older in group living facilities.
- Everyone over age 65, critical workers in high-risk situations (teachers, health-care workers), people with underlying health conditions putting them at moderate risk, and people under age 65 who are in prisons, jails, or detention centers.
- Young adults age 18 to 30, children (if safe for them), and people who work in industries such as banks, higher education, hotels, and factories.
- Everyone else.
It is interesting to note here that young adults, as the most active spreaders, would receive vaccines earlier than most older adults under age 65.
On Nov. 20, Pfizer became the first pharmaceutical company to file for FDA emergency authorization (the approval of an unapproved medical product) for its COVID-19 vaccine. Moderna, a biotech company, is expected to file for emergency authorization soon.
Pfizer has said it expects to produce enough to vaccinate 12.5 million Americans by the end of this year, or about 3.7% of the nation’s population of 330 million.
Other manufacturers, like AstraZeneca (which reported a success rate of more than 90% in clinical trials) and several dozen others may be gaining approval as well. Still widespread availability of vaccines to all Americans isn’t expected until late 2021.
The road ahead for vaccination against COVID-19 is full of uncertainties.
We’ve taken a major step with the early successes in clinical trials. But the sheer physical challenge of manufacturing and distributing vaccines for 330 million people is daunting.
In addition to scaling up production of the vaccines themselves, factories also need to ramp up production of vials, needles, and other equipment. Some vaccines need to be frozen in extreme cold, requiring the construction and distribution of large refrigerated units.
Meanwhile, until the day comes when you can be vaccinated, it will remain important to follow the same safety rules you’ve probably been following since March. Stay at home as much as possible, wear masks, and practice social distancing when you’re out.
The end of the pandemic may be in sight. We need to be patient just a bit longer.