To really control the pandemic, most people around the world need to be vaccinated against COVID-19. It is a difficult task that involves billions of shots.
By the end of this year, only about 70 million doses of the COVID-19 vaccines from Pfizer and BioNTech and Moderna and the National Institutes of Health are expected to be shipped worldwide. Next year, that number will jump to more than 1 billion. Other companies are also working on vaccines, but some populations may still not have access until 2024.
Meanwhile, the death toll continues to rise.
So why can’t doses be pumped and distributed more quickly?
Considering that vaccines can take years just to be created – and that Pfizer and Moderna vaccines have moved from concept to testing and implantation in less than a year – the pace is already fast.
Then there is the question of how many people need it: an unprecedented amount in the pharmaceutical industry.
“We have never distributed vaccines on that scale before,” said Lois Privor-Dumm, director of adult vaccines at the Johns Hopkins Bloomberg School of Public Health’s International Vaccine Access Center. “We are talking about trying to reach the entire planet, essentially.”
On the manufacturing side, there is a race to expand production to more factories, which need to be equipped with specialized equipment, and to train workers. And once made, Pfizer and Moderna vaccines must be kept in freezing temperatures so that they cannot be distributed in any vehicle or stored in any warehouse.
“It’s not like making widgets,” said Nancy Pire-Smerkanich, an assistant professor of regulatory and quality sciences at the USC School of Pharmacy.
Instead of spending time and money to build new factories to expand their capacity, pharmaceutical companies – including Pfizer and Moderna – are turning mainly to contractors specializing in vaccine manufacturing.
Pfizer is using several of its own factories in the US and Belgium and is partnering with outside companies to increase production, a spokeswoman said. Moderna, whose business historically did not involve much production, is more dependent on third parties.
Vaccine development can be a lengthy process, but the annual flu vaccine is produced in a much shorter time than some other vaccines. This is possible because all the technology has already been established – it is just a matter of changing the strains of influenza that researchers predict will be dominant that year, said Pire-Smerkanich.
For the 2020-2021 flu season, vaccine manufacturers hope to make up to 198 million doses for the United States alone, according to the Centers for Disease Control and Prevention.
Making the COVID-19 vaccines is different: manufacturers started from scratch, but are using a faster process.
Pfizer and Moderna sockets use a technology called messenger RNA, or mRNA. These molecules instruct cells to make a specific type of protein that is also found in the coronavirus, and that protein stimulates the immune system to produce antibodies that would target the virus.
The mRNA technique accelerates the vaccine development process.
Many flu vaccines take about six months to be made because they depend on the growth of the virus in chicken eggs. The mRNA technique, on the other hand, is developed in the laboratory and can be done much more quickly – in 2013, Novartis researchers took eight days to make a potential flu vaccine.
This mRNA technology has been studied for decades, but no vaccine for humans has used the technique so far.
A major challenge with this technique is that the mRNA is fragile, which is why Pfizer and Moderna vaccines must be frozen. The Pfizer vaccine should be kept at minus 94 degrees Fahrenheit; Moderna’s is more stable and can be stored at minus-4 degrees and lasts 30 days in an ordinary refrigerator. Both vaccines can be kept out of refrigeration for short periods of time.
The deep-frozen temperatures required for the Pfizer vaccine complicate the shipping process: the vials must be packed in freezer boxes with dry ice, and a large shipment may contain more dry ice than is normally allowed on airplanes – a limit imposed due to risk of carbon dioxide poisoning.
If production and transport could be increased instantly, the bottleneck would be to find places for all those doses to be maintained until use. Companies specializing in cold storage operations are now in high demand; LA County purchased more than a dozen ultra-cold storage freezers to maintain the vaccine prior to distribution. As it stands, this need is likely to pose a problem in countries whose power grids are less installed.
“If 90% of the world is not vaccinated, the virus will still be out there,” said Rhiju Das, associate professor of biochemistry at Stanford University School of Medicine. “This really needs to be a worldwide immunization effort, otherwise COVID will stay with us for a long time.”
Both vaccines require two doses, meaning healthcare systems will need to maintain control over who took the first injection and remind people to return for the second, said Christopher Tang, a distinguished professor and professor of business administration at UCLA Anderson School of Management.
And the vaccine manufacturing process is specialized, involving equipment that is sometimes made to measure and workers trained in the raw material, equipment operation, packaging and quality control. Each batch of vaccine is tested and inspected before doses are sent for distribution, and it all takes time.
“As much as we have automated the business, there is still a level of expertise needed to do this,” said Pire-Smerkanich.
Experts say the speed of the process was a major achievement.
In the world of vaccine development, failure rates are high, and manufacturers often try several options before finding one that works, according to a May article in the New England Journal of Medicine.
And sometimes success comes too late.
For example, the development of the SARS and Zika vaccine was completed after both epidemics ended in 2003 and the mid-2010s, respectively. Federal agencies then reallocated funds for vaccine research, “leaving manufacturers at financial loss and delaying other vaccine development programs,” according to the New England Journal of Medicine article.
In that case, vaccines were created in time to play a crucial role in reducing the COVID-19 pandemic. Now it’s a matter of unrolling them.
“I don’t think we saw anything on that scale,” said Eugene Schneller, professor of supply chain management at Arizona State University and a visiting researcher at the UCLA Fielding School of Public Health. “Although you would like to have more … I think we did and we are doing very well. The proof will be in the pudding of the consistency and quality of these vaccines as they arrive, and in the integrity of the whole process.”
This story originally appeared in the Los Angeles Times.