A large, throbbing and inflamed, red to purple, warm, painful area around the injection site that measured between 3 cm by 3 cm to 5 cm by 5 cm; The physician likens the site reaction to something similar to serum sickness; A large, throbbing and inflamed, red to purple, warm, painful area around the injection site that measured between 3 cm by 3 cm to 5 cm by 5 cm; A large, throbbing and inflamed, red to purple, warm, painful area around the injection site that measured between 3 cm by 3 cm to 5 cm by 5 cm; A large, throbbing and inflamed, red to purple, warm, painful area around the injection site that measured between 3 cm by 3 cm to 5 cm by 5 cm; A large, throbbing and inflamed, red to purple, warm, painful area around the injection site that measured between 3 cm by 3 cm to 5 cm by 5 cm; This spontaneous case was received on 15-Oct-2020 from a physician via Health Authority (reference number: SEQW20-03743) with additional document (being processed together) received on 19-Oct-2020 (reference number: SEQW20-03917) and concerned a female adult patient of an unspecified age. The patient was between 20 to 50 years old.  The patient's medical history and concomitant medications were not reported.  On an unspecified date in Oct-2020 (since 12-Oct-2020), the patient was vaccinated with Flucelvax Quadrivalent (influenza vaccine, subunit influenza virus vaccine polyvalent; dose: 0.5 ml, route of administration: intramuscular and anatomical location: deltoid) for protection against seasonal influenza. The batch number reported was 283844 and expiry date: 30-Jun-2021.  On the same day, about an hour after receiving Flucelvax Quadrivalent, the patient developed large, throbbing and inflamed, red to purple, warm, painful area around the injection site that measured between 3 cm by 3 cm to 5 cm by 5 cm. The patient's arm started to bleed out of the injection site so badly that the blood saturated the bandage applied to it. The physician stated that he had never seen anything quite like this in his years of practice and likened the site reaction to something similar to serum sickness. The patient was advised to apply ice and to take ibuprofen and the events were alleviated.   On an unspecified date in Oct-2020, about 36 hours after the onset of events, the patient recovered from the events.  The reporter assessed the events as related to Flucelvax Quadrivalent. The reporter was concerned of this adverse reaction that he had recently seen with Flucelvax Quadrivalent. In his 20 years of practice, the reporter had never noted this many severe injection site reaction in such a short amount of time and stated that seeing injection site reaction this severe from this lot (283844) made him nervous and apprehensive about administering more vaccines.  The case was assessed as non-serious.  This case is linked to the cases 202005247, 202005248, 202005274, 202005276 and 202005294 (the same reporter).  Company comment: Pain, serum sickness-like reaction, vaccination site warmth, vaccination site inflammation, vaccination site erythema and vaccination site pain were associated with the use of the suspect product Flucelvax Quadrivalent. The events started to emerge about an hour after vaccination making chronology highly suggestive to the product. The patient's medical history and concomitant medications were not reported. With information presented, causality is assessed as probably related for all events due to suggestive temporal relationship and lack of other confounding factors.; Reporter's Comments: The reporter assessed the events as related to Flucelvax Quadrivalent. The reporter was concerned of this adverse reaction that he had recently seen with Flucelvax Quadrivalent. In his 20 years of practice, the reporter had never noted this many severe injection site reaction in such a short amount of time and stated that seeing injection site reaction this severe from this lot (283844) made him nervous and apprehensive about administering more vaccines.; Sender's Comments: Pain, serum sickness-like reaction, vaccination site warmth, vaccination site inflammation, vaccination site erythema and vaccination site pain were associated with the use of the suspect product Flucelvax Quadrivalent. The events started to emerge about an hour after vaccination making chronology highly suggestive to the product. The patient's medical history and concomitant medications were not reported. With information presented, causality is assessed as probably related for all events due to suggestive temporal relationship and lack of other confounding factors.