after her First Moderna COVID-19 vaccine the patient experiences no seasonal allergies; Patient had a sore swollen deltoid muscle; redness at the injection site; Swollen lymph nodes under the arm pit; the patient started sneezing with watery nose, and itchy watery eyes/  patient's seasonal allergies had returned; localized swelling with redness at the injection site; This spontaneous case was reported by an other health care professional and describes the occurrence of SEASONAL ALLERGY (the patient started sneezing with watery nose, and itchy watery eyes/  patient's seasonal allergies had returned), THERAPEUTIC RESPONSE UNEXPECTED (after her First Moderna COVID-19 vaccine the patient experiences no seasonal allergies), MYALGIA (Patient had a sore swollen deltoid muscle), INJECTION SITE ERYTHEMA (redness at the injection site) and LYMPHADENOPATHY (Swollen lymph nodes under the arm pit) in a female patient of an unknown age who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 025J20-2A, 025J20-2A, 053E21A and 055A22A) for COVID-19 prophylaxis. The occurrence of additional non-serious events is detailed below.     Concurrent medical conditions included Exercise induced asthma (mild) and Chronic myeloid leukemia (in remission for 20 years). Concomitant products included DASATINIB MONOHYDRATE (SPRYCEL) for Leukemia, FUROSEMIDE and POTASSIUM for an unknown indication.   On 23-Dec-2020, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 20-Jan-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 02-Sep-2021, received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 08-Aug-2022, received fourth dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. In 2021, the patient experienced INJECTION SITE SWELLING (localized swelling with redness at the injection site). In 2023, the patient experienced SEASONAL ALLERGY (the patient started sneezing with watery nose, and itchy watery eyes/  patient's seasonal allergies had returned). On an unknown date, the patient experienced THERAPEUTIC RESPONSE UNEXPECTED (after her First Moderna COVID-19 vaccine the patient experiences no seasonal allergies), MYALGIA (Patient had a sore swollen deltoid muscle), INJECTION SITE ERYTHEMA (redness at the injection site) and LYMPHADENOPATHY (Swollen lymph nodes under the arm pit). The patient was treated with CLARITHROMYCIN (CLARITIN [CLARITHROMYCIN]) from August 2023 to 08-Oct-2023 for Seasonal allergy, at an unspecified dose and frequency; OLOPATADINE HYDROCHLORIDE (PATANOL) for Seasonal allergy, at an unspecified dose and frequency and CETIRIZINE HYDROCHLORIDE (ZYRTEC [CETIRIZINE HYDROCHLORIDE]) for Seasonal allergy, at an unspecified dose and frequency. On 05-Oct-2023, SEASONAL ALLERGY (the patient started sneezing with watery nose, and itchy watery eyes/  patient's seasonal allergies had returned) had resolved. At the time of the report, THERAPEUTIC RESPONSE UNEXPECTED (after her First Moderna COVID-19 vaccine the patient experiences no seasonal allergies) outcome was unknown, MYALGIA (Patient had a sore swollen deltoid muscle) and INJECTION SITE SWELLING (localized swelling with redness at the injection site) had resolved with sequelae, INJECTION SITE ERYTHEMA (redness at the injection site) was resolving and LYMPHADENOPATHY (Swollen lymph nodes under the arm pit) had resolved.        For mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown), the reporter did not provide any causality assessments.   After receiving first dose of Moderna vaccine, patient had a sore swollen deltoid muscle with redness at the injection site and swollen lymph nodes under the arm pit.  The patient normally had to start taking seasonal allergy medication in late February of each year, however she noticed that she was not having Seasonal allergies by late Feb-2021. The patient had suffered from seasonal allergies for years and had a routine where she starts to prepare for the allergies however starting in 2021 after her First Moderna COVID-19 vaccine the patient experienced no seasonal allergies.  After receiving second dose of Moderna vaccine, patient had a sore Deltoid muscle, redness at injection site and localized swelling. Patient noticed the following spring she did not have any seasonal allergies.  After receiving third dose of Moderna vaccine, patient had a sore deltoid muscle and localized swelling with redness at the injection site. The patient did not have any allergies that Fall.  After receiving fourth dose of Moderna vaccine, patient had sore deltoid muscle and localized swelling with redness at the injection site. The patient did not have any allergies that Fall.  The patient had her next Moderna COVID-19 vaccine 14 months after her 4th vaccine of Moderna COVID-19 vaccine. 12 months after her 4th dose of the Moderna COVID -19 vaccine the patient started sneezing with watery nose, and itchy watery eyes. The patient's seasonal allergies had returned, and the patient started taking Claritin, and Patanol eye drops. Sometimes the symptoms were getting so bad the patient took Zyrtec. The patient had no seasonal allergies after her fourth Moderna COVID-19 vaccine until 12 months after the 4th dose of vaccine. Starting 12 months after her fourth vaccine the allergies came back and resolved 5 days after her 5th (First Spikevax dose).   This case was linked to US-MODERNATX, INC.-MOD-2023-746349 (E2B Linked Report).; Sender's Comments:  US-MODERNATX, INC.-MOD-2023-746349:Same Patient, Dose 5 (SPIKEVAX 2023-2024 PFS)