Maintenance antiretroviral therapy with combination of two injectable long-acting drugs, cabotegravir and rilpivirine, is a new strategy addressing the challenges of daily adherence to oral pills that has shown non-inferior efficacy to standard of care therapy in patients with suppressed HIV-infection. Patients co-infected with hepatitis B virus (HBV) are not eligible for this dual therapy since it has no activity against HBV, but this strategy should also be restricted to patients with anti-HBs antibodies since people with HIV are still at risk of HBV acquisition due to high risk behavior and since HBV vaccination does not always elicit anti-HBs antibodies, as highlighted in the case report below.