他去年七月有症狀，但比較輕。
一般認為需要90天以後打疫苗。
Mayo Clinic: Getting COVID-19 might offer some natural protection or immunity from reinfection with the virus that causes COVID-19. But it's not clear how long this protection lasts. Because reinfection is possible and COVID-19 can cause severe medical complications, it's recommended that people who have already had COVID-19 get a COVID-19 vaccine. If you’ve had COVID-19, you might delay vaccination until 90 days after your diagnosis. Reinfection with the virus that causes COVID-19 is uncommon in the 90 days after you are first infected.
