New Jersey health officials are working on plans to launch a network of statewide vaccination sites to administer booster shots this fall, which could include reopening the “mega-sites” used to administer large numbers of vaccines earlier this year.

“We are planning for a range of scenarios,” Health Commissioner Judith Persichilli said.

As the highly transmissible delta variant spreads across the country, overwhelming hospitals in other states, the Biden administration announced the booster-shot campaign last week, days after health officials had recommended moderately and severely immunocompromised people receive a third shot of the two-dose Moderna and Pfizer vaccines. The shots’ effectiveness in protecting against mild infection from the delta variant may fade beginning six months after the second dose, according to several new studies. The White House coronavirus response said they worried protection against severe infection could also diminish over time, as it has in other highly vaccinated places that are grappling with delta.

Starting the week of Sept. 20, booster shots are set to be offered nationwide, eight months after the second dose. That means health workers, nursing-home residents and staff, seniors, and people with certain health conditions — all of whom were among the first group to be eligible for vaccines early this winter — will be in the front of the line.

» READ MORE: COVID-19 booster shots are on the way for more of us starting in September. Here’s what you need to know.

New Jersey health officials are working with long-term care facilities to provide booster shots. Outbreaks in nursing homes and other facilities are on the rise, which Persichilli said she found “very concerning.”

The state added 1,443 cases and three deaths. Hospitalizations continue to rise, though the numbers remain far below the peaks seen earlier in the pandemic.

“As the delta variant continues its rampage, we are seeing an increase in the number of breakthrough cases,” Gov. Phil Murphy said, but he added that the overwhelming majority of hospitalizations and deaths have been among the unvaccinated.

“There is no doubt that the vaccines are helping prevent infection,” he said.

New Jersey officials also said there will be adequate supplies for all who want the shots this time.

“We do expect a scramble, as we saw in the beginning,” Persichilli said. “The difference is, we have many more outlets for people to get vaccinated. We will put out guidelines and support people as best we can.”

» READ MORE: In Philly and its suburbs, health leaders plan for a booster shot rollout: ‘The situation will be better this time around’

Officials said the state was prepared to administer a large number of booster shots quickly, particularly if the models of case counts suggest another surge this fall as more activities move indoors.

“When the boosters are ready to go for prime time, the most important thing we can do to impact the modeling is get everybody up to bat and get the booster shot when they should get it, as fast as possible,” Murphy said.

Pennsylvania has yet to announce any specific plans about its booster-shot rollout. A Department of Health spokesperson said Friday that the commonwealth plans to use its existing network of 3,000 vaccine providers to administer the shots, with the ability for more sites to be added if necessary, and that people do not need to get a booster at the same location where they got their first and second doses. Pennsylvania health officials are confident that this rollout will be smooth, and say the most vulnerable people, including residents of long-term care facilities, will be prioritized.

”We are in a much different situation in terms of vaccine availability and vaccine providers than where we were at the beginning of the vaccine roll out,” the department said in a statement. “In the beginning, the sole issue was that vaccine supply was not meeting the demand in Pennsylvania — now that is not an issue.”