SUSPECTED VACCINATION FAILURE (NO ANTIBODY RESPONSE); TOOTH INFECTION; TONSILLITIS; SINUS PAIN; CALF MUSCLE PAIN ON BOTH LEGS; This spontaneous report received from a patient concerned a female of unspecified age. The patient's height, and weight were not reported. The patient's concurrent conditions included obese, asthmatic, smoker, allergies, seasonal sinus infection, seasonal tonsillitis, and dental problems, and other pre-existing medical conditions included unknown.  The patient received covid-19 vaccine ad26.cov2.s (suspension for injection, intramuscular, batch number: 1805031, and expiry: UNKNOWN) dose was not reported, administered on 04-MAR-2021 14:25 for prophylactic vaccination on left arm. No concomitant medications were reported.  On 05-MAR-2021, the patient experienced calf muscle pain on both legs. On 18-MAR-2021, Laboratory data included: Antibody test (NR: not provided) Negative for IGG or IGM antibodies. On 20-MAR-2021, the subject experienced tonsillitis. On 20-MAR-2021, the patient experienced sinus pain. On 22-MAR-2021, Laboratory data included: Antibody test (NR: not provided) Negative for IGG or IGM antibodies. On 23-MAR-2021, treatment medications included: amoxicillin. On 25-MAR-2021, Laboratory data included: Antibody test (NR: not provided) Negative for IGG or IGM antibodies. On 26-MAR-2021, treatment medications included: erythromycin. On 29-MAR-2021, Laboratory data included: Antibody test (NR: not provided) Negative for IGG or IGM antibodies. On an unspecified date, the patient experienced suspected vaccination failure (no antibody response), and tooth infection. The action taken with covid-19 vaccine ad26.cov2.s was not applicable. The patient recovered from calf muscle pain on both legs on 10-MAR-2021, and the outcome of suspected vaccination failure (no antibody response), tooth infection, tonsillitis and sinus pain was not reported. This report was serious (Other Medically Important Condition).  Additional information was received from patient on 29-MAR-2021. The following information was updated and incorporated in to the case narrative: The patient demographic details added (sex, race and ethnic origin), concurrent condition added (seasonal tonsillitis, sinus infection, tooth disorder, allergies),  lab data added (rapid antibody tests), event deleted (no antibody response and lower leg pain), events added(no antibody response was recoded to suspected immunological vaccination failure, calf pain in both legs, tooth infection, tonsillitis, sinus pain), treatment drugs added (amoxicillin and erythromycin), vaccination site and time added, vaccine facility details added.; Sender's Comments: V1: The following information was updated in this version: The patient demographic details added (sex, race and ethnic origin), concurrent condition added (seasonal tonsillitis, sinus infection, tooth disorder, allergies),  lab data added (rapid antibody tests), event deleted (no antibody response and lower leg pain), events added(no antibody response was recoded to suspected immunological vaccination failure, calf pain in both legs, tooth infection, tonsillitis, sinus pain), treatment drugs added (amoxicillin and erythromycin), vaccination site and time added, vaccine facility details added.  20210331196 - Covid-19 Vaccine Ad26.Cov2.S - Suspected Vaccination Failure (No Antibody Response). This event is considered not related. The event has a compatible/suggestive temporal relationship, is unlabeled, and has unknown scientific plausibility. There are other factors more likely to be associated with the event than the drug. Specifically: SPECIAL SITUATIONS.