Vaccine Injury Table onset windows: what happens inside and outside them

The Vaccine Injury Table lists, for each covered vaccine, the injuries that are presumed to be caused by it and the window in which the first symptom must appear. Meet the window and the burden shifts: the government must prove another cause. Miss it and you must prove causation yourself under Althen. The table below is the program's own record of how much that presumption is worth.

The main windows

• SIRVA (any intramuscular vaccine in the arm): pain within 48 hours.
• Guillain-Barré syndrome after seasonal influenza vaccine: onset 3 to 42 days.
• Encephalopathy or encephalitis: within 72 hours of a pertussis-containing vaccine (DTaP, Tdap); 5 to 15 days after a measles-containing vaccine (MMR, MMRV).
• Brachial neuritis after a tetanus-containing vaccine: 2 to 28 days.
• Anaphylaxis: within 4 hours of most vaccines.
• Vasovagal syncope: within 1 hour.

Transverse myelitis, chronic inflammatory demyelinating polyneuropathy and most other neurological claims are not on the Table at all, so every one of them is an Althen case regardless of timing.

Why onset is the whole case

Onset is the date the first symptom appeared, not the date of diagnosis, and it is fixed by the medical record rather than by memory. A claimant who reports shoulder pain to a doctor three weeks after the shot will be asked why the record is silent for those three weeks, and a Guillain-Barré claim whose first documented weakness is on day 50 has left the window. Petitioners' counsel spend much of their effort establishing onset from pharmacy records, work absences and text messages precisely because the presumption depends on it.

The registry's onset intervals page plots every stated onset against the windows and shows how the win rate moves across the boundary.

Related: Onset intervals vs Table windows · How cases are decided · GBS cases