A New York health care worker suffered from a severe allergic reaction after receiving the first shot of a coronavirus vaccine, city officials said on Wednesday. 

The two leading companies that received emergency use authorization from the U.S. Food and Drug Administration (FDA) for its COVID-19 vaccines used similar technology in developing and producing them. But days after the vaccines were given, there were reports of allergic reactions.

Read also: U.S. Health Worker Reports Serious Allergic Reaction to Pfizer Vaccine 

Health Care Worker Experienced Serious Adverse Reaction

Health care workers are part of the first group to receive the COVID-19 vaccine under the Centers for Disease Control and Prevention (CDC) guidelines. However, there were cases of serious allergic reactions after the first shot was given. 

Officials confirmed Wednesday that a health care worker in New York experienced a severe adverse reaction after getting a first shot of the COVID-19 vaccine.

According to a published article in The Hill, the incident was the first reported adverse reaction in the city.

New York City Health Commissioner David Chokshi confirmed this during a news conference and said that the unidentified health care worker experienced a significant allergic reaction to the vaccine. But he assured the healthcare worker was already treated and is now in stable condition and recovering.

He added that his department has been tracking reports of the vaccines' side effects and is working closely with the CDC. He also advised those who have allergic reactions to previous vaccines or injectable medications to consult their doctors before getting a COVID-19 vaccine.

FDA Investigating the Report

Despite different reports across the country of persons who experienced allergic reactions to the vaccine, Chokshi said: "For the vast, vast majority of people who have allergies that situation doesn't apply. The COVID-19 vaccine will be safe and effective for those people and everyone else."

According to the FDA, they are now investigating multiple reports of adverse reactions on Pfizer-BioNTech's vaccine in Alaska and other states. 

The agency's Center for Biologics Evaluation and Research Head Peter Marks said on Friday that it was unclear what caused the reactions. However, he indicated that the allergic reaction's possible culprit is the chemical called polyethylene glycol, which is both presents in Pfizer and Moderna. 

Following this, the CDC recently issued new guidelines and advised those who received the first shot and have a severe allergic reaction not to get the second shot.

The CDC also recommended seeking immediate medical attention by calling 911 if you get a vaccine and you think you might be having a severe allergic reaction after leaving a vaccination site.

Health regulators in the United Kingdom have also warned those who experienced significant histories of allergic reactions not to get the COVID-19 vaccine of Pfizer after two people reported experiencing adverse reactions earlier this month.

Meanwhile, New York officials said they would continue to move forward with the COVID-19 vaccine distribution to ensure that health care workers and nursing home staff, and city residents are protected against the virus.

Read also: CDC Issues New Guidance to Address Allergic Reactions to Coronavirus Vaccine