Indeed, it does look like if you have HIV with a weak immune system your more at risk.
https://www.nhs.uk/conditions/corona...m-coronavirus/
You or your child may continue to be at high risk of getting seriously ill from COVID-19, despite vaccination, if you have:
- Down's syndrome
- certain types of cancer (such as a blood cancer like leukaemia or lymphoma)
- sickle cell disease
- certain conditions affecting your blood
- chronic kidney disease (CKD) stage 4 or 5
- severe liver disease
- had an organ or bone marrow transplant
- certain autoimmune or inflammatory conditions (such as rheumatoid arthritis or inflammatory bowel disease)
- HIV or AIDS and have a weakened immune system
- a condition affecting your immune system
- a rare condition affecting the brain or nerves (multiple sclerosis, motor neurone disease, Huntington’s disease or myasthenia gravis)
- a severe problem with the brain or nerves, such as cerebral palsy
- severe or multiple learning disabilities (or you're on the learning disability register)
- a weakened immune system due to a medical treatment (such as steroid medicine, biological therapy, chemotherapy or radiotherapy)