Clinical Trial Assessing the Immunogenicity of an Anti-pneumococcal Vaccination Strategy (PCV13+PPV23 Versus PREVENAR20) in Adult Patients Treated for a Lymphoma

To join this study, you need to be an adult (18 or older) who is currently being looked after by a blood cancer specialist (hematology unit). You should also have recently started or received your first course of chemotherapy for a specific type of lymphoma, either diffuse large B cell lymphoma or follicular lymphoma. You'd also need to be expected to live for at least six more months.

There are some reasons why you might not be able to join. For example, if you're taking certain medications that affect your immune system (other than standard lymphoma chemotherapy), or if you have an uncontrolled infection. You also can't have had a pneumonia vaccine recently, or have conditions like HIV, a very weak immune system, or severe kidney disease.

Safety is very important, so if you've ever had a severe allergic reaction to a vaccine or have serious blood clotting problems, you wouldn't be able to take part. Also, pregnant women or women who could become pregnant and are not using effective contraception cannot join the study.

If you decide to take part, you'll be assigned to one of two groups: one group will receive two separate pneumonia vaccines (Prevenar 13, followed by Pneumovax 23 two months later), and the other group will receive one dose of the PREVENAR20 vaccine. You'll have several study visits over about a year or so, starting from when you get your first vaccine.

At these visits, blood samples will be taken to check your immune response to the vaccine. These checks will happen before vaccination, and at several points afterwards – for example, about a month after each vaccine dose, and then again at 3, 6, and 12 months later (the exact timings might vary slightly depending on which vaccine group you're in). Doctors will also watch carefully for any side effects from the vaccination.