Speeding vaccination – a supply chain problem


Category : Medical Rants

Many critics have emerged on COVID19 vaccination speed.  News channels have interviewed experts who seem confused as to why we are giving vaccines so slowly.  They should read the work of Eliyahu Goldratt who championed the Theory of Constraints.  His books could certainly help policy makers look at vaccination queues in a very different way.

In his novel, The Goal, he wrote:

… the professor discloses the Theory of Constraints: “A bottleneck is any resource whose capacity is equal to or less than the demand placed upon it. A non-bottleneck is any resource whose capacity is greater than the demand placed on it.” Jonah carefully explains that Alex must NOT try to balance capacity with demand, but instead balance the flow of product through the plant. 

Our current capacity for delivering vaccines does not meet the demand.  Thus, we have a clear bottleneck.  What makes this even more complex is that we currently have multiple bottlenecks in vaccine distribution.  Unfortunately, each state develops its own bottlenecks.  In my state, the Department of Public Health has written this policy:

Beginning the week of December 28, residents and employees of Long-Term Care facilities began receiving vaccination through the federal Pharmacy Partnership.  Once persons in Phase 1a have been offered the vaccine, Alabama will move into Phase 1b.

This policy has developed a bottleneck.  We are waiting for everyone in Phase 1a to have vaccination offered before moving to the next tier.  This strategy, based on CDC recommendations, slows down the vaccination process.  Other states have similar bottlenecks.

Here is the key question: How does one protect Tier 1a candidates and yet use all the available vaccines?  One possibility is through staggered scheduling.  Each site determines how many vaccines they can deliver each day.  Now this number will be an estimate given that some 5 dose vials actually have 6 (or even 7) doses.  We have learned that many vials contain enough extra volume to get 1 or 2 extra doses from the vial.

Let’s assume 50 available vaccines for next Thursday.  Today is Friday and the schedule opens for all Tier 1a candidates.  They are notified that they need to make their appointment by Tuesday.  If Tuesday comes and there are any unclaimed slots, those slots will become available to Tier 1b candidates.  Finally, on Wednesday the site opens a “last minute” list.  This list would be for anyone in Tier 1a or 1b who is willing to come either a scheduled person misses or cancels their appointment or extra doses (from vials) become available.

In this scenario, the vaccination site would deliver all the available doses for that day.  Unfortunately, we have read reports of some sites having to discard doses at the end of the day. With appointments we also diminish the risk of a super spreader event from too many people waiting in line for long periods of time.

Given such a system, we would then potentially develop a second bottleneck – vaccine supply.  The solution to vaccine supply problems is more complex but represents the problem we can more easily accept.

We have a responsibility to vaccinate as many people as we can as quickly as we can.  Priority lists are useful, but they should not slow the vaccination process.  Tier 1a candidates should always carry a priority.  Unfortunately, many Tier 1a candidates have had the opportunity to receive the vaccine but have declined.  When they change their mind, they can make an appointment in this system. 

Once we see significantly decreasing need for Tier 1a, we open up Tier 1b for advanced appointments and let Tier 1c make the later appointments and register for the “last minute” list.

Achieving “warp speed” in vaccine delivery requires a flexible system that both respects each Tier but does not delay vaccines for the next Tier when the higher priority Tier is not using all the potential slots.  We need to remove the artificial constraints to achieving a highly efficient supply chain.  We have enough demand; we must match the supply to the demand as reasonably as possible.

Comments (3)

The supply chain problem is real for the developing countries. It is very difficult to maintain a very low temperature for a long time.

A very thoughtful article. Thanks for sharing

Your point of view is very good. Totally agreed

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