/sci/ - Science & Math

>>12426557
It means exactly what it says in the article. WHO-defined grading:
>Participants recorded solicited local reactions (pain,redness, swelling, induration, ecchymosis, and itching) and systemic adverse events (fever, headache, myalgia, arthralgia, nausea, chills, and fatigue) on diary cards for days 0–7 after each vaccination. Solicited adverse events were graded for severity according to predefined criteria based on WHO guidance. Briefly, solicited local reactions(erythema, induration, and swelling) whose largest diameter was more than 100 mm and systemic adverse events that prevented normal daily activity were considered as grade 3 (severe) adverse events.
In other words, the symptomatically that you would expect from a strong immune response, and non-life threatening.