1 Sept 2021

Drones to Deliver Vaccines?!?


In recent months, there was hype in the media about using drones – remote controlled small flying craft – to deliver vaccines. The banter got excited when a government agency invited drone operators to set up a pilot project for delivering medical supplies. It was promptly assumed drones would be to supply COVID19 vaccine to poorly connected rural areas, especially villages in remote mountain regions.

The premise for considering such a vaccine delivery mechanism inferred that many rural parts of India do not have suitable infrastructure and roads to enable last-mile connectivity. I was reached out, for opinion and guidance on how drones could safely bridge the gaps in cold-chain logistics for vaccines.

My immediate response was that the idea is inefficient at multiple levels and I saw no urgent purpose to use drones for delivering these vaccines.

Below are some of the reasons and other comments I expressed-

First, merely delivering a load of vaccines to any location not a sufficient condition. The fact is, the last-mile of vaccine delivery is the vaccine-giver. Before using drones to deliver vaccines, at these so called ‘hard-to-reach’ locations, deliver a trained vaccine handler and vaccine-giver. Would they be para-dropped? Focusing on supplying vials alone does not do the job and is an example of linear thinking.

Next, the design and capacity of all logistics connectivity depends on what it is intended for. In this case, the load is vaccines - which come in a tertiary cold-chain package, for example, 3000 doses of Covishield come in a package of 1 ft x 0.6 ft X 0.5 ft (containing 6 cartons of 7” x 4” x 3”, each with 500 doses – see overview on packaging sizes by WHO)

From perspective of vaccine logistics, such a small volume does not require heavy-duty trucks and associated roads. It can easily be moved on any mode of transport, even a jungle bike. The vaccine boxes come with cold packs and qualified to maintain the temperature for a finite time (duration-index of the packing). Consider a vaccine carrying box with a duration-index of 96 hours, or 4 days; this is the time available after vials exit the source fridge until they enter a destination fridge. This time is normally ample, but if there is no electricity or fridge at destination, then the vaccines begin to spoil.

If the remote area has 3000 vaccine recipients, and it does have a trained vaccinator who can dose 100 vaccinations per day, we are talking of a 30-day period. Hence, the target ‘out-of-reach’ area, should also have a vaccine refrigerator with power (grid powered or solar powered) and a person trained to maintain the stock supplied. It might even be preferable to consider a small freezer to recharge and replenish the passive cooling packs in the vaccine carrier, instead of a special vaccine fridge.

The alternative, after confirming there is a vaccine-giver, is daily drone deliveries of 100 vials – presuming 100 recipients will show up every day. The other, is to run a drone every 3 or 4 days to deliver a stock of encapsulated PCM (phase change material), or the more commonly used cold gel packs. If this is done before expiry of 96 hours, the vaccines can be kept safe for the few weeks until all of it is delivered in people’s arms. In locations without any means of cooling, I foresee the supply of chill-packs will be far more time-critical, urgent and frequent in nature, and here drones could be relevant.

Keep in mind, one instance of vaccine supply for a small hamlet, will serve the purpose for vaccinating all the people in such a location (FYI, 85 per cent of our villages are population <5000, 14 per cent about 5-10,000 and rest are >10,000). Again, the load for most of these destinations is small, the fact that drones are being considered tells each box is an odd kilo. These specially designed cold-chain packages keep the inside between 2 to 8°C and typically qualified for 48 to 120 hours. The knack is to make sure the vaccine vials connect and transfer to a suitably cooled space at destination, well within this time period.

However, lastly, wherever there are people living, there is some form of logistics connectivity – especially in India. If a postman can reach a village, consumer goods like shampoo and soap can reach rural areas, so can the planned delivery of vaccine. The logistics connectivity in India is readily evidenced when every five years the Election Commission fulfils its mandate to have a voter booth at no more than 2 kms from any citizen. Even a locale having just one voter is connected and this same can be replicated - see article War Games with COVID19 from last year. However, it means revamping the vaccination strategy – to move away from current criterion which is copied from the west, and adopt one that is more indigenous and suits the Indian backdrop.

Temporary problems do arise in road connectivity, that too due to weather or a blockage in passage, mainly in hilly terrain. Drones too, will be subject to weather vagaries, though definitely handy to counter bridge collapses or bypass landslides. Yet, in these instances, clearing the road to re-enable connectivity for food and other supplies would be the more urgent priority. The range of drones is also limited, at times by patchy radio signals in mountainous terrain.

That Govt agencies want to try out drone delivery options, is not cause for excitement. It is their job to pre-empt any probable worst-case scenarios, as well evaluate what is the most efficient and has highest impact. Planning should focus on outcomes instead of hastily grasping tools that do not really bridge the gaps. Eventually, a system approach must manifest, as knee jerk reactions are wasteful. COVID19 vaccine supply can even be done on horseback, provided it is planned in advance as it ought to be.

Drones could be more appropriately deployed where an unplanned emergency has manifested. A sudden uptick in the spread of the virus, in any unvaccinated locale – urban or rural – should demand the emergency upscaling of vaccinations. An area notified as a containment zone, should not simply imply the containment of people, but as the target zone to divert and focus associated efforts to vaccinate every person in that area – it is about containing the spread of the virus. A designated containment zone should not have to wait for the vaccine to arrive by normal means over ensuing weeks... here, to immediately scale up their supply of vaccines, is where drones can be deployed in quick-time. However, all of this will remain conjecture until we have sufficient vials and vaccine-givers to administer the doses.

Besides vaccines, which can move in comparative bulk and should be planned in advance, there is always need to replenish emergency medicines. A vaccination site is supposed to function only if it has a stock of drugs to manage anaphylactic shock. For example, minimum 3 epinephrine injections are required at all times for a vaccination site to be functional. When, and if, a vaccine recipient suffers an allergic reaction, this quantity can fall below the required minimum . In that case, all vaccinations must cease at that site, until the emergency drug is replenished. Such replenishment, random and rare, takes on an urgency to avoid further vaccination delays. Such critical connections can be considered with drones.

The supply of items whose demand is erratic, stock is minimal and which cannot readily pre-planned can greatly benefit from urgent drone deliveries. Drones can come handy for the critical and urgent supply of anti-venom, anaphylactic drugs, first aid kits and such life-saving items such as at accident sites - these typically have unplanned and sporadic consumption and should be replenished when used or have expired. The common use of drones for e-commerce deliveries is forthcoming, but until it becomes commonplace and feasible, the pandemic fight can be better focused.

The use of technology should be more holistically thought through and be outcome-oriented. Sometimes it is easier to fall prey to technology and get carried away by the marvel of it, perceived or real.

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