Adverse events
Serious adverse events, which can cause death and disability, include:
Severe infusion reaction
Cardiac arrest
Cytokine release syndrome
Tumor lysis syndrome, causing acute kidney injury
Infections
Hepatitis B reactivation
Other viral infections
Progressive multifocal leukoencephalopathy (PML) caused by JC virus reactivation
Invasive fungal infections 
Immune toxicity, with depletion of B cells in 70% to 80% of lymphoma patients
Pulmonary toxicity
Bowel obstruction and perforationTwo patients with systemic lupus erythematosus died of progressive multifocal leukoencephalopathy (PML) after being treated with rituximab. PML is caused by activation of JC virus, a common virus in the brain which is usually latent. Reactivation of the JC virus usually results in death or severe brain damage.At least one patient with rheumatoid arthritis developed PML after treatment with rituximab.Rituximab has been reported as a possible cofactor in a chronic hepatitis E infection in a person with lymphoma. Hepatitis E infection is normally an acute infection, suggesting the drug in combination with lymphoma may have weakened the bodys immune response to the virus.A major concern with continuous rituximab treatment is the difficulty to induce a proper vaccine response. This was brought into focus during the COVID-19 pandemic, where persons with multiple sclerosis and rituximab treatment had higher risk of severe COVID-19. In persons with rituximab treatment for multiple sclerosis, 9 of 10 patients with B cell counts of 40/µL or more developed protective levels of antibodies after vaccination with tozinameran. Mechanisms of action
The antibody binds to the cell surface protein CD20.
Efficacy
The U.S. Centers for Disease Control and Prevention (CDC) reports that clinical trials found the following levels of protection against Hepatitis A and Hepatitis B one month after each dose:
A: 93.8%, 98.8%, 99.9%
B: 30.8%, 78.2%, 98.5%GlaxoSmithKline claims that its studies found 70% of subjects had antibodies against hepatitis B a month after just the first dose, however.Twinrix should not be used for postexposure prophylaxis, because no data are available on the efficacy of combination vaccine for prophylaxis after exposure to HAV. Availability
Twinrix is a brand manufactured by GlaxoSmithKline Biologicals. The full generic name is hepatitis A inactivated & hepatitis B (recombinant) vaccine. Twinrix is administered over three doses. The name was created because it is a mixture of two earlier vaccines — Havrix, an inactivated-virus Hepatitis A vaccine, and Engerix-B, a recombinant Hepatitis B vaccine. Twinrix first entered the market in early 1997.In the United States, Twinrix is approved by the Food and Drug Administration (FDA) for those aged 18 and older. In some countries outside the United States, notably Canada and in the European Union, Twinrix is known as Twinrix Adult or Ambirix and a pediatric formulation, called Twinrix Junior or Twinrix Paediatric, is available. Society and culture
Economics
By being a combination it may reduce administrative costs and achieve a better uptake of the vaccine. Names
Brand names include Twinrix, Twinrix Junior, Twinrix paediatric, Ambirix, and Bilive. References
External links
"Twinrix". Food and Drug Administration (FDA). 3 October 2019.