Covid jab antibody immune response absent for some

Some patients with impaired immune systems have a low or absent antibody response after receiving two doses of Covid vaccine, a UK study has found.

Experts do not yet know what that means for protection, but say booster shots are probably a good idea for certain immunosuppressed people.

It includes those with vasculitis who are taking a strong medicine called rituximab.

Some other countries have already started giving out booster Covid doses, BBC reported.

The UK is expected to begin offering vulnerable groups a booster shot next month, but is waiting for recommendations from an independent advisory body called the JCVI.

Findings from lab tests on blood samples from 600 of these volunteers, published as a pre-print by The Lancet medical journal, suggest:

40% have a sub-optimal antibody response after two doses of either the AstraZeneca or Pfizer vaccine
Of those, 11% fail to generate any detectable antibodies four weeks after two vaccine doses – many were patients with vasculitis on the drug rituximab

But 60% had antibody levels comparable to healthy young people and all of them had optimal levels of another type of immune cell response – T cells – that can clear coronavirus infection from the body.