Duggan, a Democrat who has been mayor since 2014, said he turned down the shipment because the city is able to meet current demand with its supply of the Pfizer/BioNTech and Moderna vaccines — even as his administration expanded vaccine eligibility Thursday to residents ages 50 and older with chronic medical conditions.

“So, Johnson & Johnson is a very good vaccine. Moderna and Pfizer are the best. And I am going to do everything I can to make sure the residents of the City of Detroit get the best,” Duggan said during a news conference Thursday.

The US Food and Drug Administration on Saturday authorized the one-dose J&J vaccine, which was found to be 72% effective in the US against moderate to severe/critical Covid-19 cases. Clinical trials showed the two-dose Pfizer and Moderna vaccines were about 95% effective.