The Japanese government said Saturday it has received reports of hives and chills as potential side effects from coronavirus vaccination, in the wake of the vaccine rollout in the country earlier this week.

It is the first time to confirm possible side effects from COVID-19 vaccination in Japan. The hives case occurred at a hospital in central Japan's Toyama Prefecture on Friday, the prime minister's office said in a tweet.

Toyama Rosai Hospital said the hives occurred in a person after inoculation but the symptoms quickly disappeared. The hospital has declined to reveal details about the person.

The hospital, along with another one in the prefecture, began administering the vaccine on health care workers from Friday. On that day, 48 people received vaccinations at the hospital.

The ministry and other officials said the case of chills was initially reported as a symptom of anaphylaxis, which was later retracted. The ministry has not disclosed from what prefecture the case was reported.

Japan launched its vaccination effort on Wednesday, initially for 40,000 medical workers at 100 hospitals across the country. There have been no reports of serious side effects of the vaccine developed by U.S. drugmaker Pfizer Inc. and Germany's BioNTech SE.

If a person dies due to side effects following a coronavirus vaccination, the government will pay 44.2 million yen ($419,000) in compensation to the bereaved family, according to the health ministry.

Of the initial group of 40,000 health workers, 20,000 are taking part in a study to track potential side effects caused by the vaccine. They are asked to keep daily records for seven weeks after taking the first of two shots. The shots will be administered three weeks apart.