Ocrevus (ocrelizumab) is a medication used primarily to treat multiple sclerosis (MS) by targeting and depleting certain immune cells called B cells. Because it suppresses parts of the immune system, it can increase the risk of infections, including viral infections like shingles. Shingles is caused by the reactivation of the varicella-zoster virus, which remains dormant in nerve cells after a person has had chickenpox. When the immune system is weakened or suppressed, this virus can reactivate, leading to shingles.
Ocrevus can potentially trigger shingles because it lowers the body’s immune defenses, making it easier for latent viruses such as varicella-zoster to become active again. Serious herpes virus infections, including those caused by varicella-zoster, have been reported in patients receiving Ocrevus, sometimes with severe complications like encephalitis or disseminated skin infections. These infections can occur at any time during treatment, indicating a continuous risk while on the medication. This risk is heightened when Ocrevus is combined with other immunosuppressive therapies, which can further weaken the immune system.
The mechanism behind this increased risk involves Ocrevus targeting CD20-positive B cells, which play a role in immune surveillance and controlling latent infections. By depleting these B cells, the immune system’s ability to keep the varicella-zoster virus in check diminishes, allowing the virus to reactivate and cause shingles.
Patients on Ocrevus should be closely monitored for signs of herpes virus infections, including shingles. Early symptoms of shingles include localized pain, burning, or tingling sensations followed by a rash that typically appears on one side of the body. Because shingles can lead to complications such as postherpetic neuralgia (long-lasting nerve pain), prompt diagnosis and treatment are important.
Preventive measures may include vaccination against shingles before starting Ocrevus therapy, especially since the shingles vaccine can reduce the risk of reactivation. However, live vaccines are generally contraindicated during immunosuppressive treatment, so vaccination timing must be carefully planned with healthcare providers. The newer recombinant shingles vaccine, which is not live, may be a safer option for immunocompromised patients, but this should be discussed with a doctor.
In summary, Ocrevus can trigger shingles by suppressing the immune system and allowing the dormant varicella-zoster virus to reactivate. Patients receiving Ocrevus should be aware of this risk, monitored for symptoms, and consider vaccination strategies to reduce the likelihood of shingles. Managing this risk is an important part of the overall care plan for people undergoing treatment with Ocrevus.
