Walmart Inc is preparing to offer Covid-19 vaccinations in seven more states, as well as in Chicago and Puerto Rico, this week and the next, a company spokeswoman said, expanding beyond the two states where its pharmacists are offering inoculations.

The move from the world’s largest retailer comes as US President Joe Biden races to accelerate a frustratingly slow vaccination campaign that has stranded about half of 38 million shots in freezers.

This week and the next, Walmart will start providing inoculations in Georgia, Indiana, Louisiana, Maryland, New Jersey, South Carolina and Texas as well as in Chicago and Puerto Rico, the spokeswoman said.