(NewsNation Now) — Health officials in Alaska have reported that a second health care worker had an adverse reaction to a COVID-19 vaccine.

Some of Alaska’s hospital-based frontline healthcare workers were the first to receive the Pfizer COVID-19 vaccine Tuesday.

Bartlett Regional Hospital in Juneau says the two workers showed adverse reactions about 10 minutes after receiving the vaccine and were treated. One was vaccinated Wednesday and has fully recovered.

The other worker had a serious allergic reaction Tuesday 10 minutes after receiving the vaccine at the Juneau hospital, according to the Alaska Department of Health and Social Services.

The woman’s symptoms included flushing and shortness of breath. The symptoms were discovered during the 15-minute observation period recommended by the CDC.

The woman, who did not have a history of allergies, was given Benadryl after the symptoms began and when they did not resolve, she was transferred to the hospital’s emergency room. She was also given Pepcid, Benadryl and epinephrine and was kept overnight. She remains in the hospital in stable condition.

“We expected that a side effect like this could occur after reports of anaphylaxis were made in England after people there received the Pfizer-BioNTech COVID-19 vaccine,” said Alaska’s Chief Medical Officer Dr. Anne Zink. “All sites that are approved to provide vaccinations in Alaska must have medications on hand to deal with an allergic reaction and that was the case in Juneau.”

U.S. health authorities warned doctors to be on the lookout for rare allergic reactions when they rolled out the first vaccine, made by Pfizer and Germany’s BioNTech.

Every facility administering vaccine is being notified of this event, the Alaska Department of Health and Social Services said.

More hospitals around the state are expected to receive vaccines this week. The vaccine will be offered to Alaskans in phases, though vaccine allocation is limited and first available to:

• Hospital-based front-line health care workers at highest risk for COVID-19 infection
• Long-term care facility residents and staff (defined to include skilled nursing facilities, assisted
living homes, and Department of Corrections infirmaries providing care that is similar to
assisted living)
• EMS and fire personnel providing medical services
• Community Health Aides/Practitioners
• Individuals who are required to perform vaccinations

The Associated Press contributed to this report