Julia
The filler is not make from the bacteria, it is made by the bacteria. Many steps go into the process of preparing this very high grade product for human use. However, a tiny percentage of individuals with allergies to bacteria antigens are warned about the possibility of allergic reactions due to this exposure. It is important to stress that this is rare.
It is much more likely that any flu like symptoms after a Restylane treatment will be cause by something else. In looking at large studies that are required to obtain FDA approval, flu like symptoms are common. This is because flu and colds are very common and the majority of individuals in these studies with these symptoms have them because they are in fact coming down with a cold at the time of being enrolled in the study. The cold symptoms and the treatment have nothing to do with each other.
Complicating this issue, some individuals who have lip edge treatment, for example, will develop a cold sore from the minor stress of the treatment. This sore, which is caused by the herpes simplex virus, can also be associated with flu like symptoms.
Bottom line, unless you have a history of bacterial sepsis, or are "allergic " to everything, or know from prior testing that you may be allergic to streptococcus antigen, it is extremely improbable that you will have a reaction to Restylane treatment including a flu like immune response. For this reason routine patch testing that was recommend for collagen implants is not recommended prior to hyaluronic acid implants. Clinical experience confirms that there is a very low incidence of allergic reactions to these excellent products.