From labs to jabs
The journey of COVID-19 vaccines from creation to inoculation
The frontrunners in the global COVID-19 vaccine race have emerged and the first injections have been administered in Britain, the United States and elsewhere. But the route to distribute these much-anticipated vaccines across the world will be a challenge that will require deep freezes, careful timing, planes, trains, trucks and maybe even some intrepid donkeys.
Below is a look at the journeys of three leading experimental vaccines that have been effective in preventing infections of the novel coronavirus in late-stage trials. The first is from Pfizer Inc and BioNTech SE, the second is from Moderna Inc with the U.S. National Institute of Allergy and Infectious Diseases, and the third is from AstraZeneca and Oxford University.
Source of the vaccine
Some vaccines are gambling on promising technologies, while others are relying on approaches that have proven successful in the past.
New mRNA technology
Both of these vaccines use a chemical messenger to instruct the body’s cells to make proteins similar to the spike proteins on the new coronavirus.
Modified carrier virus
A weakened chimpanzee cold virus has been altered to include the genetic sequence of the coronavirus spike proteins.
Vials
Critical to the effective storage of temperature-sensitive vaccines, vials can render medicines unusable if damaged.
Moderna vaccine
10 doses in a vial and each person will need 2 doses given 28 days apart.
AstraZeneca vaccine
8-10 doses in a vial and each person will need 2 doses given 28 days apart.
Pfizer vaccine
5 doses in a vial and each person will need 2 doses given 21 days apart.
Cold chain
The process of distribution and storage at cold temperatures to keep vaccines stable.
Established cold chain
Most pharmaceutical distribution companies are able to store and move the two vaccines.
Bespoke ultra-cold containers
Thermal shippers maintained at -70°C using dry-ice. GPS enabled temperature trackers help monitor vaccine stability.
Container with dry ice sits above the vaccines.
Each tray can fit 195 vials.
1 to 5 trays fit in the inner payload carton and once closed, dry ice fills the sides and spaces.
Medium thermal shipper is about the size of a carry-on suitcase.
Within the company
Pfizer and BioNTech plan to make raw materials and produce the vaccine themselves.
Contracting services
Swiss contract drug manufacturer Lonza will be producing much of the Moderna vaccine along with other contractors and Moderna itself.
Using global infrastructure
Able to produce in existing sites, AstraZeneca has signed supply and manufacturing deals around the world.
Source of the vaccine
Some vaccines are gambling on promising technologies, while others are relying on approaches that have proven successful in the past.
New mRNA technology
Both of these vaccines use a chemical messenger to instruct the body’s cells to make proteins similar to the spike proteins on the new coronavirus.
Modified carrier virus
A weakened chimpanzee cold virus has been altered to include the genetic sequence of the coronavirus spike proteins.
Vials
Critical to the effective storage of vaccines, vials can render medicines unusable if damaged.
10 doses
in a vial and each person will need 2 doses given 28 days apart.
5 doses
in a vial and each person will need 2 doses given 21 days apart.
8-10 doses
in a vial and each person will need 2 doses given 28 days apart.
Cold chain
The process of distribution and storage at cold temperatures to keep vaccines stable.
Established cold chain
Most pharmaceutical distribution companies are able to store and move the two vaccines.
Bespoke ultra-cold containers
Thermal shippers maintained at -70°C using dry-ice. GPS enabled temperature trackers help monitor vaccine stability.
Container with dry ice sits above the vaccines.
Each tray can fit 195 vials.
1 to 5 trays fit in the inner payload carton and once closed, dry ice fills the sides and spaces.
Medium thermal shipper is about the size of a carry-on suitcase.
Within the company
Pfizer and BioNTech plan to make raw materials and produce the vaccine themselves.
Contracting services
Swiss contract drug manufacturer Lonza will be producing much of the Moderna vaccine.
Using global infrastructure
AstraZeneca has signed supply and manufacturing deals around the world.
Source of the vaccine
Some vaccines are gambling on promising technologies, while others are relying on approaches that have proven successful in the past.
New mRNA technology
Both of these vaccines use a chemical messenger to instruct the body’s cells to make proteins similar to the spike proteins on the new coronavirus.
Modified carrier virus
A weakened chimpanzee cold virus has been altered to include the genetic sequence of the coronavirus spike proteins.
Vials
Critical to the effective storage of temperature-sensitive vaccines, vials can render medicines unusable if damaged.
5 doses
in a vial and each person will need 2 doses given 21 days apart.
10 doses
in a vial and each person will need 2 doses given 28 days apart.
8-10 doses
in a vial and each person will need 2 doses given 28 days apart.
Cold chain
The process of distribution and storage at cold temperatures to keep vaccines stable.
Bespoke ultra-cold containers
Thermal shippers maintained at -70°C using dry-ice. GPS enabled temperature trackers help monitor vaccine stability.
Established cold chain
Most pharmaceutical distribution companies are able to store and move the two vaccines.
Container with dry ice sits above the vaccines.
Each tray can fit 195 vials.
1 to 5 trays fit in the inner payload carton and once closed, dry ice fills the sides and spaces.
Medium thermal shipper is about the size of a carry-on suitcase.
Within the company
Pfizer and BioNTech plan to make raw materials and produce the vaccine themselves.
Using global sites
AstraZeneca has signed supply and manufacturing deals around the world.
Contracting services
Swiss contract drug manufacturer Lonza will be producing much of the Moderna vaccine.
Planes, trains and trucks
Typically, airlines use containers with cooling materials, such as dry ice, to transport pharmaceutical products, but some don’t have temperature controls, making products susceptible to unforeseen events such as flight delays.
Airlines are now considering options ranging from a large plug-in freezer, which can cost about as much as a small car, to a multi-layered canister that uses liquid nitrogen to ship vaccines requiring a deep freeze.
Some trucks will be packed with dry ice and others will be refrigerated. Some will have no temperature controls and will rely solely on the cooling stability of the vaccine transport coolers.
Unlike Pfizer’s vaccine which needs to be shipped and stored at -70 Celsius (-94 F), the Moderna and AstraZeneca vaccines do not require specialized ultra-cold freezers or vast quantities of dry ice, making it easier to supply rural and remote areas. UNICEF is working with manufacturers and other partners to procure COVID-19 vaccines for poorer countries, as well as help them with freight, logistics and storage.
The U.N. children’s agency, which has experience delivering medicines to all corners of the world, calls the “cold chain” a complex undertaking that requires precise coordination in temperature-controlled environments to prevent a vaccine from losing its potency. “From storage facilities down to the village level, health workers carry vaccines in cold boxes and vaccine carriers, traveling by car, motorcycle, bicycle, donkey, camel or on foot to immunize every last child, even in the most remote of villages,”, UNICEF said on its website.
Awaiting vaccination
As vaccines travel from the manufacturer to the clinics, shipments will cross time zones and different environments. But the integrity of the vaccine relies on stable, consistent temperatures.
If the correct cold chain temperatures are maintained, all three vaccines will have a shelf life of about six months. But vaccines are sensitive to temperature variations and once stability is compromised, it cannot be recovered. Temperatures should be monitored throughout the vaccine’s shelf life.
Vaccines can be removed from their long-term, temperature-controlled environments anytime before the six-month expiry date. But once refrigerated or in room temperature, the time of stability becomes shorter.
Into the arms of the people
Once out of storage, the coronavirus vaccines all have different requirements for prepping. The AstraZeneca vaccine can be administered straight from the vial. The Moderna dose needs a gentle swirl after the vial is thawed. And the Pfizer vaccine, fresh out of a deep freeze, will require dilution and repeated inversion, but do not shake.
The attention and consideration necessary for the Pfizer vaccine could require specialist skills that may not be available in all corners of the globe. Timings and protocol will need to be followed closely.
Storage at vaccination facilities
Established cold chain
Moderna and AstraZeneca vaccines can be stored in existing medical freezers and refrigerators.
Specialist storage
Stability of the Pfizer vaccine requires specialist ultra-cold freezers and storage.
Vaccination prep
Frozen vaccines must be thawed and brought up to room temperature before being used. The vials should be inspected for any discolouration or visible particles.
Onsite work
Once thawed, the Pfizer vaccine must be diluted with a saline solution in the vial and be gently inverted 10 times.
Ready to go from the vial
Moderna and AstraZeneca vaccines do not require onsite dilution or special handling.
Injection
Syringes and needles of appropriate gauge and length are required for people of different age, gender and weight.
Shot in the arm
Vaccines are administered by intramuscular injection into the upper arm.
Second dose
The booster shot helps bolster the immune response.
AstraZeneca
4 weeks later
AstraZeneca is considering combining its vaccine with others to see if it can boost efficacy.
Efficacy
The percent reduction in the number of infections in the vaccinated group compared to the unvaccinated group.
Efficacy in adults over 65 years, who are at particular risk from the virus, was over 94%
With no serious safety concerns and a 100% success rate in preventing severe cases
62% effective with two full doses, but it was 90% effective in a small group of trial subjects who received first a half dose, then a full dose.
Storage at vaccination facilities
Specialist storage
Stability of the Pfizer vaccine requires specialist ultra-cold freezers and storage.
Established cold chain
Moderna and AstraZeneca vaccines can be stored in existing medical freezers and refrigerators.
Vaccination prep
Frozen vaccines must be thawed and brought up to room temperature before being used.
The vials should be inspected for any discolouration or visible particles.
Onsite work
Once thawed, the Pfizer vaccine must be diluted with a saline solution in the vial and be gently inverted 10 times.
Ready to go from the vial
Moderna and AstraZeneca vaccines do not require onsite dilution or special handling.
Injection
Syringes and needles of appropriate gauge and length are required for people of different age, gender and weight.
Shot in the arm
Vaccines are administered by intramuscular injection into the upper arm.
Second dose
The booster shot helps in bolstering the immune response.
Pfizer vaccine
3 weeks later
AstraZeneca vaccine
4 weeks later
AstraZeneca is considering combining its vaccine with others including Sputnik V, developed by Russia’s Gamaleya Institute, to see if it can boost efficacy.
Moderna vaccine
4 weeks later
Efficacy
The percent reduction in the number of infections in the vaccinated group compared to the unvaccinated group.
Efficacy in adults over 65 years, who are at particular risk from the virus, was over 94%
With no serious safety concerns and a 100% success rate in preventing severe cases
62% effective with two full doses, but it was 90% effective in a small group of trial subjects who received first a half dose, then a full dose.
Storage at vaccination facilities
Specialist storage
Stability of the Pfizer vaccine requires specialist ultra-cold freezers and storage.
Established cold chain
Moderna and AstraZeneca vaccines can be stored in existing medical freezers and refrigerators.
Vaccination prep
Frozen vaccines must be thawed and brought to room temperature before use. The vials should be inspected for any irregularities.
Onsite work
Once thawed, the Pfizer vaccine must be diluted with a saline solution in the vial and be gently inverted 10 times.
Ready to go from the vial
Moderna and AstraZeneca vaccines do not require onsite dilution or special handling.
Injection
Syringes and needles of appropriate gauge and length are required for people of different age, gender and weight.
Shot in the arm
Vaccines are administered by intramuscular injection into the upper arm.
Second dose
The booster shot helps bolster the immune response.
AstraZeneca is considering combining its vaccine with others to see if it can boost efficacy.
Efficacy
The percent reduction in the number of infections in the vaccinated group compared to the unvaccinated group.
Efficacy in adults over 65 years, who are at particular risk from the virus, was over 94%
With no serious safety concerns and a 100% success rate in preventing severe cases
62% effective with two full doses, but it was 90% effective in a small group of trial subjects who received first a half dose, then a full dose.
Generally, a vaccine’s real-world effectiveness tends to be slightly lower than its efficacy in clinical trials.
In the real world, there are multiple, unpredictable factors, including how many, or few, people adhere to the optimum dosing schedule and timetable; how individuals’ immune systems respond; whether the vaccine was stored at the correct temperature; whether people know, or don’t know, if they have been exposed before.
It is also not known how long a vaccine will protect someone from the SARS-CoV-2 coronavirus. BioNTech Chief Executive Officer Ugur Sahin has said he is optimistic the immunization effect of the vaccine would last for a year.Experts say that it is likely we will have to live alongside the virus.
The evidence suggests that the COVID-19 vaccines developed by Pfizer-BioNtech, Moderna and AstraZeneca will help stop people developing the disease. Only AstraZeneca’s data, so far, shows signs that its vaccine may also help prevent transmission of the virus.
Sources
Pfizer; Moderna; AstraZeneca; World Health Organization; U.S. Centers for Disease Control and Prevention; Public Health England, UK government; Reuters
By Michael Ovaska and Prasanta Kumar Dutta
Edited by
Simon Scarr and Tiffany Wu