The first doses of COVID-19 vaccine are soon headed to Wisconsin and plans are being finalized for how to distribute them.

“Distributing the COVID-19 vaccine is the most significant public health undertaking of our lifetimes,” Department of Health Services Deputy Secretary Julie Willems Van Dijk said.

The Pfizer vaccine, which must be kept at ultra-cold temperatures will be delivered to hub regions across the state which have adequate cold storage. Vaccines will then be distributed to smaller clinics around the hub area. This is known as the hub and spoke model, according to Van Dijk.

The Moderna vaccine, which does not have the same critical temperature-handling requirements will be delivered directly to vaccinators, according to DHS.

The first shipment of vaccine will be about 49,725 doses, with the same number available for the second dose, Van Dijk said. The vaccine will be allocated to health systems which can vaccinate their own at-risk healthcare workers and also emergency medical workers on the front lines.

Afterward, other essential workers, people over age 65 and people with underlying conditions such as asthma, heart disease and diabetes will be prioritized over the general public, according to DHS, which anticipates broad-based vaccinations to be available toward the summer. Health officials say those who have had COVID-19 should still be vaccinated.

States await the formal FDA emergency use authorization, but doses of the vaccine are anticipated to start arriving in Wisconsin as early as next week. People should continue to wear masks and social distance during the roll-out of the vaccine, according to health officials.