Japan is particularly raising concerns about the risks of myocarditis in young men injected with Pfizer or Moderna’s vaccines. The country is enforcing a strict legal reporting requirement of side effects that must take place within 28 days of the injections.
Three Covid-19 injections treatments are currently offered in Japan. They include the Pfizer/BioNTech (Comirnaty) and Takeda’s Moderna formulation. The product descriptions (here and here) state that “this product contains an additive that has never been used in a vaccine before.”
Furthermore, the pharmaceutical companies urge you to consult your doctor about the additive if you plan to be injected with it. In addition to the Pfizer and Moderna injections, Vaxzevria (originally Oxford/AstraZeneca) is also administered in Japan.
However, Japan only recommends it to people 40-years-old and over. Reference is also made to the new type of additive in the Vaxzevria injections.