Ms. Cohen noted that a total of 6,584 vaccinations had been completed through the program as of Friday, in part because on each visit, vaccinators may also give shots to others in the home who qualify. While the Johnson & Johnson pause had brought the program to a complete halt, within days, some of its providers had been able to start administering Moderna vaccines instead. The city’s main homebound vaccine effort, run by the Fire Department, is still hoping to return to using the Johnson & Johnson vaccine if it is again approved by federal regulators, officials said. The program will switch to Moderna if it is not, though the two visits needed and the temperature requirements for storage would make the program much more complex.