Japan's health ministry reported nine new incidents of people experiencing severe allergic reactions after receiving a coronavirus vaccine, with the minister in charge of vaccination efforts saying Wednesday that such incidents were high in Japan.
The minister in charge of vaccination efforts Taro Kono said occurrences of anaphylaxis after receiving the coronavirus vaccine developed by U.S. pharmaceutical giant Pfizer and its German partner BioNTech SE, were higher in Japan than in the United States and Europe.
The total cases of anaphylaxis among health care workers being inoculated here has risen to 17, the health ministry said.
Anaphylaxis is a potentially lethal and acute allergic reaction to an antigen to which the body has become hypersensitive.
"It's true, this seems to be more than in the United States and Europe," Kono told a parliamentary committee, after detailing 17 cases of anaphylaxis reported among the 107,558 health care workers who had been inoculated as of Tuesday.
By comparison, five cases of anaphylaxis in every 1 million doses given in the United States have been reported and 20 cases per 1 million in Britain.
Japan's public broadcaster NHK said the ratio of those going into anaphylactic shock after receiving the Pfizer jab in Japan was about one in 6,300 people.
According to the health ministry, medical facilities reported that female medical workers aged in their 20s to 50s were the ones to experience anaphylaxis after receiving the Pfizer-BioNTech COVID-19 vaccine.
The symptoms of anaphylaxis include, but are not limited to, coughing, wheezing, tightness in the chest, general pain, trouble breathing, rapid heartbeat, swollen or itchy throat, tightness in the throat, vomiting, diarrhea and a weak pulse, health experts here said.
They added that when someone goes into potentially life-threatening anaphylactic shock, which among the symptoms will almost certainly include their blood pressure suddenly dropping, a narrowing of their airways, and the blocking of normal breathing, they need immediate emergency medical attention.
If the reaction is not treated immediately, it can result in serious complications and can be fatal, they said.
In addition, according to the experts, as many as one out of every five people may have a second anaphylactic reaction within 12 hours of the first, known as biphasic anaphylaxis.
The health ministry here said the women who experienced anaphylaxis received the Pfizer jabs on Monday and despite displaying severe reactions, all have since recovered.
An investigation led by a panel of experts at the health ministry here has been charged with investigating whether the Pfizer jabs were responsible for sending the health workers into anaphylactic shock.
Japan's health minister Norihisa Tamura, in addition, said a ministry panel will look into the issue on Friday and try to determine whether the symptoms in Japan were as serious as those overseas.
