COVID-19 vaccine supply chain can be fixed

The output from Operation Warp Speed is struggling to get its footing. The billions of dollars invested focused primarily on developing a safe and effective vaccine as quickly as possible. Equally needed was how to effectively traverse all the links in the supply chain, particularly the last mile, to transform those vaccines into vaccinations. As a result, millions of doses of vaccines sit on shelves while willing recipients anxiously await their turn to be immunized.     

What went wrong and what can be done today to make this right?  

The biggest problem with the vaccine supply chain is the lofty promises made, which were highly unlikely to be deliverable. Over promising and under delivering created unrealistic expectations and the perception that something was wrong. In reality, getting any new supply chain up and running takes time, and the COVID-19 vaccine supply chain has demonstrated that fact. 

The significant cold chain requirements for both the Pfizer and Moderna vaccines have created supply chain challenges. Special freezers and dry ice are needed to keep the vaccines stable while in transit and during storage, creating logistical speed bumps at every turn.      

The good news is that two vaccines in Phase III clinical trials (the Johnson and Johnson adenovirus vaccine and the Novavax protein vaccine) have more manageable cold chain requirements, potentially easing some of the logistical challenges down the road. These vaccines will make it easier to transport them into sparsely populated rural areas where cold chains are more difficult to maintain.   

With the major cold chain requirements, vaccines packaged in five or 10-dose vials must be thawed in advance for administration. This requires careful planning and scheduling for those targeted for immunization. For example, if a clinic schedules 25 people during an immunization session and only 22 show up, are doses discarded? Are others available to be vaccinated on short notice?     

The solution is what the airlines use to ensure that they fill as many seats as possible on every flight: overbooking. By scheduling more people for an immunization session than vaccines available, few if any vaccines will get wasted. People should be alerted to this possibility beforehand, so they can be prepared if they need to be rescheduled. The key point is to ensure that no vaccine doses are wasted, given the limited supply available and their enormous societal value as a public asset.  

Given all the challenges with getting the first dose of the vaccine immunization, managing the second dose will be even more difficult. During the three- or four-week period after the first dose, anything from cold chain failure to delayed shipment of new vaccine stockpiles may lead to insufficient vaccines being available. Some people may simply forget to return for their second dose, requiring rescheduling and further delays. All such hiccups will invariably result in the potential for wasted vaccines and fewer people being immunized.    

The Centers for Disease Control and Prevention (CDC) recommended prioritization of immunization is important, with Tier I people in most need of immunization. What is also clear are those who would benefit the least from immediate immunization, such as those under 15 years of age. The large group of 200 million in between are more difficult to rank order and prioritize. Such decisions, with CDC guidance, should be pushed down to the state and county levels, allowing them to tailor their immunization programs to the needs of their constituents.    

The reality is that with over 300 million people to immunize in the U.S., getting 2 million people immunized each day, with a two-dose regimen, will take us to late fall 2021 before everyone has been protected. The sooner the supply chain issues are resolved and expectations are tempered, the sooner our nation can get onto the road to recovery.  

Sheldon H. Jacobson, PhD, is a founder professor of Computer Science at the University of Illinois at Urbana-Champaign. He applies his expertise in data-driven risk-based assessment to evaluate and inform public policy and public health. He served as a member of the National Academy of Medicine standing committee for the Strategic National Stockpile in 2015-2017.