One after another there have been postings on social media about the "dangers of vaccines" after a network illegally storing and selling vaccines was busted by the police. One of the most popular posts was one titled "Tragedies Caused by Vaccines", which blamed vaccine injections for the deaths and disabilities of 19 children, it was reposted many times accompanied by calls to "boycott vaccines".

What these posts will never tell you is that there is always a slight possibility that children will suffer an adverse reaction to a vaccine. Vaccines are inactivated pathogens, and they work by prompting the human immune system to produce antibodies to fight similar pathogens in the future. While most people do produce the desired antibodies after receiving a vaccine injection, a few, perhaps one in a million, will have adverse reactions because of their specific immunity conditions.

This is what the Japanese call "a demon draws lots", because although the possibility is low the unlucky person suffers a lot. Even if the vaccine is a genuine product, properly stored, there is always that possibility. Sometimes poor quality vaccines or irregular operation during their injection might cause adverse reactions, too, but the probability of that is also very low.