LOS ANGELES — California has administered more than 18 million doses as of Thursday and 6.7 million people are fully vaccinated. But the governor warned that getting to herd immunity may take months and depends on supply.

Gov. Gavin Newsom said the state administered 2.5 million shots last week, which is about the amount California expects to receive next week.

The state of nearly 40 million residents is coming back to life as more business sectors reopen following a crushing winter surge. California’s case and death rates remain low but cautious health officials have asked people to continue wearing masks and maintain social distancing rules in order to avoid another surge.

Gov. Newsom received his “one and done” Johnson & Johnson coronavirus vaccine Thursday, as people 50 and older became eligible for the coveted inoculations in the most populous state in the country.

The Democratic governor chose a public stage to receive his shot — sitting in a folding chair, steps from a bank of TV cameras while the event was livestreamed from a mostly vacant area on a lower floor of a Los Angeles shopping mall.

Wearing a mask, Newsom kept the mood light, bantering as he pulled up the short sleeve of his T-shirt to expose his upper arm. He joked that he brought his own doctor, Health and Human Services Secretary Dr. Mark Ghaly.

“Nothing to be nervous about,” Ghaly said before poking the governor with a needle.

Newsom, 53, received his vaccination as millions more Californians became eligible Thursday to make appointments for the available doses, a process that remains frustrating for many.

Unlike most residents, however, there was no waiting line for Newsom. He did not have to wade through the state’s online portal and other separate sites in an attempt to get a vaccination appointment, or wake up in the middle of the night hoping to score a last-minute opening.

He encouraged residents 50 and over to get vaccinated.

“The best vaccine is the next one available,” Newsom said.