Despite leading the world in Covid-19 vaccine production, the US has so far exported very few shots, prompting complaints that Washington has failed to do its bit to help battle the pandemic globally.

The day after taking office in January, President Joe Biden enacted wartime powers to help boost domestic medical supplies, including vaccines. The move has since been described by critics as an “embargo”, hampering supplies in some of the worst-hit countries by limiting the availability of US-made vaccine ingredients.

There is no formal export ban on vaccines or vaccine components, such as syringes, vials and filters. Companies manufacturing vaccines, or items needed by jab makers elsewhere in the world, are free to export them. 

However, Washington has used a wartime power known as the Defense Production Act to compel private companies to fulfil its contracts ahead of other orders. This has prompted manufacturers elsewhere in the world, like the Serum Institute in India, to complain of not being able to buy items they would normally import from the US. In normal times, the US is the top global exporter of syringes and needles, according to the OECD.

US officials have defended their use of the DPA. “Making vaccines requires a great deal of specialised materials, and there’s just not enough to go around,” one administration official said this week. “There’s just more global manufacturing happening everywhere in the world than suppliers can currently support.”

Separately, the US has a large stockpile of Oxford/AstraZeneca vaccine doses it bought up early in the development process. Until recently, it rebuffed requests from other countries to share those jabs.