Everyone should get a second dose. The only exception is for people who had a serious reaction to the first dose of the vaccine. This is very unusual but if you did experience a severe reaction you should speak to your healthcare professional.
In all other cases you should have the second dose. You may just need to delay your second dose if you are unwell, have a fever or are experiencing any symptoms of COVID-19:
After mild COVID-19 you can have your COVID-19 vaccine 30 days after recovering from the acute infection. This is usually around 40 days after your first symptoms.
After severe COVID-19 (needing oxygen) you need to wait 90 days for your vaccine.