Small Aircraft
Flight Crew Instrument; Flight Crew Private
Flight Crew Last 90 Days 30; Flight Crew Total 700; Flight Crew Type 165
Other / Unknown; Physiological - Other
Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Illness / Injury
General Flight Cancelled / Delayed
Environment - Non Weather Related; Human Factors
I received the second dose of vaccine against SARS-CoV-2 (virus that causes COVID). The vaccine is highly safe and effective; but clinical data show that many people have minor side effects like fatigue; muscle pains; headache; and flu-like symptoms. The FAA requires a 48 hour waiting period after administration of this vaccine for that reason.I had not reviewed the FAA circular. I concluded that it would take longer than the flight I had planned for any potential side effects to develop; so I launched on a 4 hour flight. Towards the end of this flight; I made an unscheduled fuel stop and started to develop a mild headache. Recognizing that these might be symptoms related to the vaccination; I grounded myself. Later that evening; I developed symptoms that were severe enough that they would have presented a safety issue; had I been operating an airplane.I neglected to review the FAA circular in advance of this flight. A 48 hour delay after vaccination would have prevented the possibility of experiencing symptoms that could present a danger during flight.
GA pilot reported receiving the COVID-19 vaccine and flying before the 48 hour wait period requirement.  Pilot did not read the FAA circular regarding the vaccine and developed a headache during the flight.