SINGAPORE: On Monday (Dec 21), 31 boxes of COVID-19 vaccines arrived in Singapore.
The first shipment of the Pfizer-BioNTech vaccine had been flown in from Belgium, landing at Changi Airport on Monday evening.
The precious vials then made their way to SATS Coolport's refrigerated warehouse before being loaded onto a truck for delivery to an undisclosed location in Singapore.
How are the vaccines brought from their place of production to a hospital or clinic to be injected into your arm? Here's a rough guide to their cold-chain journey:
PUURS, BELGIUM TO SINGAPORE
The Pfizer-BioNTech vaccines came direct from a manufacturing site in Puurs, Belgium, and were protected by security escorts as they made their way to Brussels International Airport, said logistics services firm DHL.
The vaccine was packed in dry ice in thermal shipper boxes designed to keep the vials at -70 degrees Celsius, which is colder than Antarctica in winter.
The boxes were then loaded onto a Singapore Airlines (SIA) Boeing 747-400 freighter, departing Brussels on Sunday night. They arrived on the tarmac at Changi Airport at 7.36pm.
WHY THE NEED FOR SOUTH POLE TEMPERATURES
The Pfizer-BioNTech vaccine, as well as one produced by Moderna, are made from genetic material called mRNA (messenger ribonucleic acid).
While they can be produced faster than traditional vaccines, they have to be stored at very low temperatures because mRNA is easily destroyed. Drug manufacturers have coated the modified mRNA in lipid nanoparticles, but it still needs to be frozen.
Pfizer's vaccine has to be stored at -70 degrees Celsius and lasts for only five days at standard refrigerator temperatures. Moderna's vaccine can be stored at -20 degrees Celsius and lasts in a fridge for 30 days.
In contrast, a traditional vaccine made from a weakened or inactivated virus such as Sinovac's can be stored at normal fridge temperatures of 2 to 8 degrees Celsius and may remain stable for up to three years.
DRY ICE & TEMPERATURE TRACKERS
To make sure the vaccines were kept cold, temperature trackers with GPS monitored the temperature and location of each box. Dry ice is required to maintain the deep-freeze temperature the fragile Pfizer-BioNTech vaccines need to be kept at.
It means that the boxes do not need to be transported in a deep freezer, as the packaging they come in can keep them unspoiled for up to 10 days unopened, according to Pfizer.
Once delivered, the Pfizer thermal shippers can be used as temporary storage for up to a month if the dry ice is refilled every five days.
This is why Singapore dry ice suppliers are anticipating greater demand for their services.
Transport Minister Ong Ye Kung said on Monday that ground handler SATS can now produce up to 4 tonnes of dry ice a day.
FRIDGES ON WHEELS, IN THE AIR
Mr Ong said that to get ready for the logistical challenge of transporting the vaccines, airlines, logistics firms and freight forwarders started the Changi Ready Taskforce a few months ago to start to resolve any potential issues before the vaccines were even in production.
SATS, for instance, has invested in cool dollies - refrigerated containers that can wheel goods from cargo planes to warehouses.
On Monday, the first shipment of Pfizer-BioNTech vaccines reached SATS' Coolport slightly after 8pm - about half an hour from when the plane landed. They were separated into three batches and immediately taken onto a chilled lorry for delivery.
The Changi Ready Taskforce has said that they are more than prepared to store and transport the vaccines at the temperatures required.
Logistics hubs here, such as this one managed by firm Kuehne+Nagel for instance, have insulated loading and unloading bays for temperature-controlled trucks, ensuring that the products are not exposed to warm temperatures outside. Capacity is not an issue as each truck can hold up to 1.5 million doses of vaccines.
Shippers also use active containers to sustain the temperature of the vaccines. The fully charged Envirotainers can last for 100 hours and are mainly used for international air freight shipping.
Mr Jens Drewes, president of Kuehne+Nagel Asia Pacific, pointed out that the availability of auxiliary equipment such as vaccine vials, syringes and alcohol swabs are just as crucial to administering vaccines.
THAW BEFORE USE
When the deep-frozen vaccine arrives at a healthcare facility, it has to be thawed and diluted before use.
It can then be kept at room temperature for a few hours. Each Pfizer-BioNTech vial contains five doses of vaccine.
Associate Professor Hsu Li Yang, vice dean of Global Health and programme leader for infectious diseases at the Saw Swee Hock School of Public Health, said that if hospitals or clinics cannot keep the vaccines at the required ultra-low temperature, they will have to work out a vaccination schedule so that they can use up all the vials they receive within five days.
For the Moderna vaccine, most hospitals and some clinics here will have -20 degrees Celsius freezers, and so there will be fewer logistic issues, he added.
Associate Professor Goh Puay Guan, from the National University of Singapore's Business School said that vaccine distribution in Singapore does not face many issues as the cold-chain capabilities are in place, and the transportation distances are not too far.
"If there are any issues, it could be from potential bottlenecks in the global supply chain during the initial months, as the vaccine manufacturing and logistics capacity is still ramping up and being put in place," he said.
He explained that a lot of cargo was traditionally carried in the holds of passenger planes, and the decline in passenger traffic earlier in the year also affected the availability of airfreight capacity.
The shortage of airfreight capacity is worsened by the increased consumer demand and online shopping during the Christmas shopping season. However, many airlines have converted their older passenger planes to full cargo planes by removing the passenger seats, so as to increase air cargo capacity.
SIA has said that it is ready to deploy seven freighters and 200 passenger aircraft for vaccine deliveries.
Another thing to look out for is the need for large amounts of dry ice (solid carbon dioxide) to maintain the temperature of the cold boxes.
"There are regulations on how much dry ice can be allowed on an airplane as too much carbon dioxide is hazardous to human health," Assoc Prof Goh said.
SIA said that it is measuring on its flights the rate at which the dry ice in the cool boxes are converted to carbon dioxide.
DHL has estimated that up to 200,000 pallet shippers and 15 million cooling boxes as well as 15,000 flights will be required to deliver vaccines worldwide for the next two years.