Vaccine

The goal of this study is to learn whether different types of vaccines to prevent bacterial infections are able to effectively create antibodies that defend against certain types of bacteria. We will give two different types of vaccine and evaluate the effectiveness of antibodies produced by each vaccine in killing bacteria.

The French Public Health Council recommended pneumococcal vaccination combined strategy for all immunocompromised patients in 2012. This strategy consisted in conjugated 13-valent pneumococcal (PCV13) injection followed 2 months later by polysaccharide 23-valent (PPV23) vaccine injection. In 2024, Health authorities changed guidelines to recommend one injection of PREVENAR20 instead of the 2-vaccine scheme general practitioners are usually in charge of this vaccination. Conjugated pneumococcal vaccine enhances the immunogenicity of the polysaccharide vaccine. Acute leukemia and lymphoma are treated with multiple courses of chemotherapy, impairing the immune system and potentially the response to vaccination. These patients are more at risk for developing pneumococcal invasive diseases than the general population. However, efficacy of pneumococcal vaccination is poorly documented in this setting. We assume that 65% of the patients are non-responders to double compared to 45% for PCV20PREVENAR20 vaccination, according to their anti-pneumococcal immunoglobulin G (Ig) titers and the opsonophagocytic activity (OPA). To assess the immunogenicity of the pneumococcal vaccination combined strategy in adult population of acute leukemia and lymphoma, we will measure anti-pneumococcal serotype-specific IgG titers and OPA at different time-points after completion of the combined vaccine strategy. The primary objective is to assess the immunogenicity of pneumococcal vaccination combined strategy at 3 months after the PCV13 injection (corresponding to 1 month after the end of the combined strategy in cohort A) using Ig G titers and OPA, compared to 3 months post PREVENAR20 (cohort B). At different time points (day 0, 4 weeks post PCV13, and 4 weeks, 3-6 months and 9-12 months post PPV23 and in day 0, 4 weeks post PREVENAR20 and 3 months, 5-8 months and 11-14 months post PREVENAR20, the immunological response to vaccination will be monitored using specific-serotype IgG titers, OPA, and total anti-pneumococcal Ig. We will determine predictive factors of non-response to vaccination by comparing demographic data, biological data and treatment received lymphoma patients. The tolerance and safety of the vaccination strategy will also be assessed in this specific hematological population.

This is a clinical study of personalized self-DC vaccine targeting neo-antigen (Neo-DC vaccine) in the treatment of advanced solid tumors.

The goal of this clinical trial is to find out which approach works better in getting more of the friends and connections of Latino adults get vaccinated against COVID-19. The main questions this study aims to answer are: 1. Can teaching people to use motivational interviewing help more friends and connections of Latino adults get the COVID-19 vaccine compared to just giving information about the vaccine? 2. What are the things that make it easier or harder for Latinos and networks to get the COVID-19 vaccine? 3. How does this intervention work in practice so that it can be made available to more people in the future The researchers will compare the vaccine rates of the friends and connections of Latinos who have been trained in motivational interviewing with those who have only been given information about the COVID-19 vaccine. This will help figure out which method works best to encourage more people to get vaccinated.

The goal of this clinical trial is to assess the safety, tolerability and immunogenicity of three dosage levels, and a single or two-dose administration regimen, of the investigational HDT-321 product administered intra-muscularly. The main questions it aims to answer are: * Is HDT-321 safe to use * Does HDT-321 provide protection against Crimean-Congo hemorrhagic fever virus (CCHFV) Researchers will record any adverse events and test blood samples to see if HDT-321 is safe and works to protect participants against Crimean-Congo hemorrhagic fever virus (CCHFV) Participants will: * Receive 1 or 2 doses of HDT-321 * Complete a memory aid and measurements for 7 days after receiving each dose of HDT-321 * Be followed throughout the study using phone calls and clinic visits to check for and record adverse events * Provide blood samples at specific study visits

This is a Phase I/IIa, randomized, double-blind, placebo-controlled, dose-escalation clinical trial to test the candidate vaccine StreptInCor. The study will include four different doses (25 µg, 50 µg, 100 µg, and 200 µg) of StreptInCor produced under Good Manufacturing Practices (GMP) and formulated with aluminum hydroxide as the vaccine adjuvant. The adjuvant alone will be used as a placebo in this trial. Five groups, each consisting of twelve healthy adult volunteers, will randomly receive two doses of the vaccine or placebo with a 28-day interval, along with a booster dose six months after the initial vaccination

CHO-V08 is currently being developed as a prevention vaccine against nosocomial and community-acquired infection caused by hypervirulent Klebsiella pneumoniae K1 and K2 serotypes. The goal of study (KLEBBI-001) is to evaluate the safety, reactogenicity, and immunogenicity of the preventive vaccine of CHO-V08 in healthy volunteers aged from 18 to 50 years old.