The New York City health department rolled out its full guidance for private-sector businesses and venues subject to a new mandatory COVID-19 vaccine policy on Wednesday, ordering them to keep compliance records on file or face fines starting at $1,000.

Under the rules, employees must provide proof of full vaccination, meaning they can take either one shot of the Johnson and Johnson vaccine or two doses of Moderna or Pfizer. If they choose the two-dose varieties, workers have 45 days from their first shot to get the second and file the record with their bosses. No matter which they pick, employees must file proof of at least one dose to their employer by December 27th, the day the mandate takes effect.

Employers must also prominently post a sign affirming they’re in compliance and keep records of those who’ve received a medical or religious exemption for the vaccine.

Mayor Bill de De Blasio noted that city agencies, including the Department of Health and Small Business Services, will begin enforcement by issuing warnings but will shift over to fines if they encounter flagrant violators. Records must be readily available to city inspectors upon random request.

“We will follow up with businesses. We will make sure they understand, we will obviously watch if there's any pattern that looks like the process is not being done in [an] accurate way," he said during his Wednesday briefing. "We follow up with them, we work to improve it.”

The final guidance offers a clearer picture of the vaccine order announced by the mayor on December 6th. He justified the mandate by pointing to the rise in omicron variant cases, an anticipated winter surge of the delta variant and large gatherings due to holiday activities.

"The vast majority of businesses want their people vaccinated," he said. "Customers of those businesses want people vaccinated.”

When de Blasio announced the private-sector mandate, he touted it as the first-of-its-kind in the U.S. Earlier this fall, President Joe Biden proposed a federal mandate for businesses but it allowed workers to choose between weekly testing and vaccination.

Children ages 12 and older must also be fully vaccinated by December 27th to take part in indoor activities; children ages 5 to 11 must have at least one dose by that date for the same privileges.

The mandate adds to a number of orders imposed on businesses and venues this month. On December 10th, Governor Kathy Hochul issued a statewide mask mandate for anyone over the age of two entering a business or venue inside, but it doesn't apply to businesses and venues that require patrons to be fully vaccinated. That took effect on Monday. Venues and businesses in violation of Hochul’s policy also face fines of up to $1,000 but local regulators are in charge of enforcement. De Blasio said Wednesday that city agencies are abiding by the state’s mask order while emphasizing the importance of vaccines.

So far, 78% of New York City residents have gotten at least one dose of the vaccine, the mayor said.

Georgia Pestana, the city's Corporation Counsel, said she was confident the city’s order can withstand any legal challenges, citing the authority carried by city Health Commissioner Dr. Dave Chokshi's orders issued in the interest of public health.

"He has the authority to issue these mandates and protect public health. It is an obligation he takes seriously, and when there is a feeling or understanding based on the science that it is time for the city to take the next step, he raises it and we move forward," Pestana said at the Wednesday briefing. "We will defend it if anyone challenges it."