The lymph node swelling was days later, in January. She hid it under a scarf for about 2 months until I noticed it during a rare face to face visit. After about 6 weeks of various tests including MRI scans and even a contrast scan (with 'dye' inserted in the body), they detected cancer in the oral area, separate to the lymph nodes in the neck. We were about 3 or 4 months after the first jab, and the 2nd had already taken place in the interim, when the diagnosis was confirmed. Sorry, I overly condensed the events and timeline, and you make good points, and I appreciate the concern for my mum. But I do think sufficient time passed for the cancer to emerge - to your point, at least 3 months later - while the medics were investigating what was up with the lymph node swelling.