Japan has found its first cases of possible adverse reactions to coronavirus vaccinations since the country began its inoculation campaign on Wednesday, health ministry officials said Saturday.

Two people developed symptoms suspected to be adverse events after vaccinations on Friday, and the symptoms disappeared soon in both cases, the officials said.

One of the two people developed hives after receiving a dose at Toyama Rosai Hospital in Uozu, Toyama Prefecture, central Japan.

The other felt a chill and shiver after getting vaccinated at a separate facility.Japan’s COVID-19 vaccination campaign, using Pfizer Inc.’s shot, first covers 40,000 medical workers.

For 20,000 of them, records of health conditions after vaccinations are being kept.

In Pfizer’s clinical tests, 66 pct to 83 pct of participants developed pain at the injection site after a dose and 34 pct to 59 pct reported fatigue.

Five cases of anaphylaxis, or severe allergic reactions, were reported per one million doses.

A 30-minute observation after taking a dose is required for anyone who has a history of anaphylaxis and at least 15 minutes for others.

JIJI Press