[nudephil (OP)]

Rita asks:

I am 70 years old but I have IgG insufficiency. Can I take the COVID vaccine?

Can anyone point her to some relevant guidance?

[evan_au]

Short Answer: Yes, you can still take a COVID vaccine. There are many parts of the immune system, and vaccines are designed to engage multiple parts of your immune system.
- You might have less vaccine protection than another person
- But it's still more protection than not having the vaccine.

Long Answer:
Your immune system has two major components, cell-mediated immunity and humoral response. igG is part of the humoral response.
See: https://en.wikipedia.org/wiki/Immune_system#Humoral_immune_response

Antibodies help defend your body from infection. IgG is just one of several types of antibodies:  IgA, IgD, IgE, IgG, and IgM
- igG (Immunoglobulin class G) is the most common one in human blood.
See: https://en.wikipedia.org/wiki/Immunoglobulin_G

There are 4 types of IgG. "igG insufficiency" often refers to an abnormally low concentration for just one type of igG.
See: https://en.wikipedia.org/wiki/IgG_deficiency

So if you have igG insufficiency, that is just one class of antibody, and antibodies are just one part of the immune system targeted by a vaccine. So a vaccine will still help you.

[set fair]

You night try asking the team on This week in virology which vaccine would be best. They have a lot of experience in vaccination programs.