Tennessee could receive its first doses of COVID-19 vaccinesas soon as Dec. 15, and vaccines could be widely available to Tennesseans by early summer, state officials announced Tuesday.

The state is prepared to distribute the vaccine immediately when it arrives, Tennessee Department of Health Commissioner Dr. Lisa Piercey said.

"This is our top priority," she said. "This is the one ray of hope that we've got, so we are putting a ton of effort forth to make sure we get it to you as fast and as safely as possible."

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The vaccine updates come as COVID-19 infections climb to new heights in Tennessee. In the past two months, the number of hospitalized COVID-19 patients increased two-and-a-half fold. One in three intensive care unit patients in the state has COVID-19, said Dr. Wendy Long, president of the Tennessee Hospital Association.

During Tennessee's last infection spike in July, COVID-19 patients made up 19% of ICU patients. Long said hospitals are "running out of levers to pull" to preserve access to critical healthcare services while addressing increasing needs for COVID-19 response.

Businesses in Tennessee's healthcare industry have started discussing allowing COVID-positive healthcare staff to work in COVID-specific units, something that is allowed by the Centers for Disease Control and Prevention, Long said, noting the hospital association has made no official recommendations, and that decision ultimately will be industry driven.

What is Tennessee's vaccine distribution plan?

Tennessee anticipates it will receive its first round of vaccines from Pfizer. The state is currently one of four states participating in the company'spilot delivery programfor the vaccine, which must be stored at ultracold temperatures. While all dates are subject to change, Tennessee will be ready to distribute vaccines around Dec. 15.

TheModerna vaccinecandidate is now expected to arrive about one week later, Piercey said.

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It is not yet clear how many vaccines Tennessee will receive, and the number of doses delivered to the state in the next few months "fluctuates widely," Piercey said. Between 80,000 and 100,000 doses are expected in the first delivery, enough to vaccinate between 40,000 and 50,000 people as the vaccine requires two doses per person.

Vaccines will be distributed in phases according to the state's draft distribution plan. Frontline healthcare workers and first responders who are the most likely to have contact with infected individuals and materials will receive the vaccine first, and Tennessee will move through the following phases as supply allows.

In the second phase, when the state expects to have enough vaccine doses to meet demand, it will prioritize vaccination of staff in schools and childcare businesses, older adults and those with illnesses who have a medium risk of complicating the virus. At this point, the vaccine also would be made available to workers in “critical infrastructure” industries: construction, utilities, food and beverage supply, public transportation and the shipping of goods.

Finally, once the vaccine has sufficient supply and demand has begun to slow, it will be provided to young adults, children, others in congregate care settings, and, eventually, everyone else.

Children and pregnant women are among the last to receive the vaccine because they are generally not included in early clinical trials that test the vaccine's safety.

Piercey expects Tennessee to complete phase one of distribution and potentially a portion or all of phase two in the winter and early spring. The remainder of phase two and phase three should be complete in late spring or early summer. Estimates predict widespread availability in July or August.

"The good news, though, is even when we start vaccinating small numbers of folks, 100,000, 200,000, I know that doesn't seem like a lot in the context of 6.8 million Tennesseans, but that's 200,000 who are not transmitting the disease," Piercey said. "So we're going to start to see some measurable improvement in our case trends when we get some vaccines in arms."

How will the vaccine be delivered?

Tennessee expects to lean on hospitals, public health agencies and pharmacies to distribute vaccines. Ideally, there will be a leasttwo locations in every county where the vaccine is available.

According to the state’s disbursement plan, the state will prioritize disbursement from hospitals with emergency rooms and ICUs. The vaccine probably will be available at every county public health agency in the state.

Finally, in rural areas where there is no hospital, vaccine will be available at local pharmacies.

The vaccine must be stored and transported at negative-94 degrees Fahrenheit, but because Tennessee covers a wide swath of land with pockets of sparse population, officials do not plan to store doses in a centralized freezer. Instead, the vaccine will be delivered using Pfizer- and manufacturer-recommended "thermal shippers."

The vaccine comes in flat boxes of 975 vials (Piercey said it "sort of looks like a pizza box). This box is packed with dry ice inside an insulated 2-foot by 2-foot cube. The dry ice is recharged on a specific schedule.

"That is what we intend to use so we can mobilize and distribute vaccines faster than having to keep going back and forth to a stationary freezer," Piercey said.

Will vaccines be required?

Whilesome universities might require students to be vaccinatedfor COVID-19 once vaccines are widely available, Gov. Bill Lee said he does not foresee mandated vaccines for K-12 school systems in Tennessee.

The University of Tennessee requires its students to get flu vaccines and might require COVID-19 vaccines as well if a vaccine is recommended by the Centers for Disease Control and Prevention and Tennessee Department of Health,according to its website.

"We support local decision-making, and that decision is theirs to make," Lee said of the University of Tennessee's potential requirement.

Lee added that vaccines will be "very important for us in the state to curb the spread of the virus and to ultimately really be able to handle it."

The speed, accuracy and safety of the vaccines approaching availability is a pleasant surprise to Lee's administration and health officials, he said.

"But, vaccines are a choice, and people have the choice and will have the choice in this state as to whether or not they should take that vaccine," Lee said.