Pandemic puts pressure on vaccine supply
Across the world, manufacturers face challenges in scaling up production “We think, ‘ Well, OK, it’s like men’s shirts, right? I’ll just have another place to make it.’ It’s just not that easy.”
With demand for COVID- 19 vaccines outpacing the world’s supplies, a frustrated public and policymakers want to know: How can we get more? A lot more. Right away.
The problem: “It’s not like adding more water to the soup,” said vaccine specialist Maria Elena Bottazzi of Baylor College of Medicine.
Makers of COVID- 19 vaccines need everything to go right as they scale up production to hundreds of millions of doses — and any little hiccup could cause a delay. Some of their ingredients have never before been produced at the sheer volume needed.
And seemingly simple suggestions that other factories switch to brewing new kinds of vaccines can’t happen overnight. Just this week, French drugmaker Sanofi took the unusual step of announcing it would help bottle and package some vaccine produced by competitor Pfizer and its German partner BioNTech. But those doses won’t start arriving until summer — and Sanofi has the space in a factory in Germany only because its own vaccine is delayed, bad news for the world’s overall supply.
“We think, ‘ Well, OK, it’s like men’s shirts, right? I’ll just have another place to make it,’” said Dr. Paul Offit of Children’s Hospital of Philadelphia, a vaccine adviser to the U. S. government. “It’s just not that easy.”
The multiple types of COVID- 19 vaccines being used in different countries all train the body to recognize the new coronavirus, mostly the spike protein that coats it. But they require different technologies, raw materials, equipment and expertise to do so.
The two vaccines authorized in the U. S so far, from Pfizer and Moderna, are made by putting a piece of genetic code called mRNA — the instructions for that spike protein — inside a little ball of fat.
Making small amounts of mRNA in a research lab is easy but “prior to this, nobody made a billion doses or 100 million or even a million doses of mRNA,” said Dr. Drew Weissman of the University of Pennsylvania, who helped pioneer mRNA technology.
Scaling up doesn’t just mean multiplying ingredients to fit a bigger vat. Creating mRNA involves a chemical reaction between genetic building blocks and enzymes, and Weissman said the enzymes don’t work as efficiently in larger volumes.
AstraZeneca’s vaccine, already used in Britain and several other countries, and one expected soon from Johnson & Johnson, are made with a cold virus that
Dr. Paul Offit, Children’s Hospital of Philadelphia
sneaks the spike protein gene into the body. It’s a very different form of manufacturing: living cells in giant bioreactors grow that cold virus, which is extracted and purified.
“If the cells get old or tired or start changing, you might get less,” Weissman said. “There’s a lot more variability and a lot more things you have to check.”
An old- fashioned variety — “inactivated” vaccines like one made by China’s Sinovac — require even more steps and stiffer biosecurity because they’re made with killed coronavirus.
One thing all vaccines have in common: They must be made under strict rules that require specially inspected facilities and frequent testing of each step, a time- consuming necessity to be confident in the quality of each batch.
Production depends on enough raw materials. Pfizer and Moderna insist they have reliable suppliers.
Even so, a U. S. government spokesman said logistics experts are working directly with vaccine makers to anticipate and solve any bottlenecks that arise.