When Bottles (as in Medical Vials) Become the Bottleneck

(Author’s note: This article was based on news articles, blogs and other online resources.)

With billions of dollars being spent for a coronavirus (COVID-19) vaccine, it could seem that all will be well once a viable one is found. However, even then, many people might still not be able to access it — a shortage of glass vials is predicted to create a bottleneck for the vaccine’s delivery.

Vials by the Numbers

Each person getting the vaccine will likely require two doses (an initial shot followed by a booster), reports say, thus creating a potential immediate need for up to 15.6 billion glass vials (the world’s population is 7.8 billion) — and more will be needed for newborns. And vials will still be needed for existing drugs and vaccines. Based on a Reuters news agency report, the current annual global production is 15 billion to 20 billion glass vials.

Recently, the World Health Organization listed more than 100 COVID-19 vaccine candidates currently being developed. Only a few are considered promising candidates. Despite no guarantee of success, manufacturers still want to ensure their share of glass vials. Larger companies with extensive supply chains can use existing ties with suppliers or manufacturers to enter long-term supply agreements — like the Corning Incorporated-Pfizer Inc. agreement reached in May — while other companies will have to make new connections with suppliers.

These developments can put pressure on other pharmaceutical companies that need vials for existing products and which must continually reach out to suppliers to assure flow is not impacted.

Medical vials are made of Type I borosilicate glass. Another type of borosilicate glass — soda-lime glass (Type III), which is used for windows, house decor and glass bottles — cannot be used for vaccine vials due to its chemical reactivity and its lack of resistance to thermal shock during the vial manufacturing process. Type I glass has better pH stability, it releases less alkali and chemicals, and it is more resistant to drastic temperature changes than Type III glass, making it the gold standard in vials making, according to an article in The Medicine Maker.

The Vial Shortage

In the short term, it seems that the current shortage is due to slow growth of the vials manufacturing industry combined with an unexpected surge in demand. The glass-vial industry is heavily capital-intensive due to the cost to acquire the equipment. Another consideration: The equipment consumes a lot of energy — the furnace used to melt the sand, for example, runs at close to 2,000 degrees when no vials are being made. Additionally, special requirements like precision details, manufacturing process control, level and intensity of quality checks lead to additional cost. Combined, these factors create a high barrier of entry, and it could be risky to invest in the industry without a promising perspective of sales.

These dynamics help explain why there are only a few major medical glass vial manufacturers in the world. Based on data from manufacturers’ websites, Corning in the U.S. and Schott AG in Germany are the largest manufacturers of medical vials, with more than US$1.2 billion (about 1 billion euros) in sales from their pharmaceutical packaging business, which also includes other items like syringes. Other major manufacturers are Gerresheimer in Germany, with annual pharmaceutical packaging sales between 500 million and 1 billion euros, followed by SGD Pharma in France and Stevanato Group in Italy (annual revenue of between 250 million and 500 million euros).

In the long term, experts say the shortage will be driven by the lack of a core ingredient: sand. Though there may be plenty of sand on the planet, not all of it is usable for glass vials. The type suitable for making Type I borosilicate glass is silica sand. Containing large amounts of silicon dioxide (SiO₂), the resulting glass is chemically inert. As the concentration of SiO₂ increases, so does the clarity and strength of the resulting glass. Silica sand is also used in construction (concrete, shingles and mortar) and in the technology industry (computer chips).

Sands such as silica sand are highly sought due to their jagged shape that can grip better, unlike desert and beach sands that are eroded into smoother grains by the wind. Most silica sand is found in river beds and lakes.

Due to the limited amount of source locations and numerous industries fighting for the material, it stands to reason the glass vial industry is impacted. According to a BBC report, sand was the second-most consumed natural resource in 2019, behind only water. With the glass industry’s most important material hard to procure, it seems there will most definitely be a general decrease in the capacity to manufacture medical vials.

Questions for the Future

The future of vaccine distribution is uncertain, and questions abound. What can governments do to reduce the shortage? Should vial manufacturers cater to the needs of the COVID-19 vaccine front-runners, thus putting the supply to other hospital patients at risk? What is being done to reserve silica sand for making medical vials? How can vials be commoditized so if a COVID-19 vaccine candidate fails, its reserved vials reserved can be used for other vaccines? Is government intervention (even beyond incentives) a viable strategy for allocating vial-manufacturing capacity? What is the best use of the limited amount of glass vials? Will shortages lead to higher vial prices, which will be passed on to the general public?

No clear answers yet exist to these questions, but there are signs that they are being addressed:

• Government incentives. For example, the U.S. government has created Operation Warp Speed. Under this program, the government has awarded funding to vial manufacturers like Corning and Auburn, Alabama-based SiO2 Materials Science to expand or accelerate capacity.
• Vial manufacturers “doing the right thing.” With many vaccine companies vying to secure supply from a limited number of vial manufacturers, leading vial makers like Schott AG could easily boost revenue by picking the highest price offered. However, the German company has turned down deals worth billions of euros because it wants to save capacity for successful vaccines. Another leading vials maker, SGD Pharma, has a similar mindset.
• To conserve limited supplies, leading vaccine companies like Pfizer are working on fitting more doses per vial, instead of the usual one dose per vial, while SiO2 Materials Science is producing a glass-plastic hybrid vial so it has the benefits of both materials.

Potential vaccines are being developed, and the vial shortage, though overwhelming, can likely be overcome with public-private collaborations based on strategic planning and technological innovation.