PubMed:: "Influenza, Human"[Mesh] OR "Influenzavirus A"[Mesh] OR "Influenza B virus"[Mesh] OR influenza*[tiab] OR flu[tiab] OR h1n1[tiab] OR grippe[tiab];; Embase.com:: 'influenza'/exp OR 'influenza virus a'/exp OR 'influenza virus b'/exp OR 'influenza virus c'/exp OR influenza*:ab,ti OR flu:ab,ti OR h1n1:ab,ti OR grippe:ab,ti;; Cochrane Library:: influenza* OR flu OR h1n1 OR grippe
