View clinical trials related to Vaccine Response Impaired.
Filter by:Viruses with high mutation rates, such influenza or HIV, pose a major challenge for vaccine design. The current influenza vaccination strategy of yearly vaccination with adapted strains aims to maximally diversify the antibody immune response to prevent viral escape. There is, however, growing evidence, that repeated vaccination with very similar viral proteins might limit, instead of broaden, diversification and thereby reduce vaccine efficacy. The ARIVA Study prospectively studies the immunological impact of repeated influenza vaccination on viral variant recognition and antibody responses in healthy subjects cross-sectionally and over three consecutive vaccination seasons.
With aging the immune system gets weaker. This makes older adults more susceptible to influenza (flu). Vaccinations help to prevent infection from the flu virus, however the immune system of older adults do not respond as well to vaccines compared to young adults and thus, aren't as well protected from the complications from the flu. This research is being done to determine if Metformin, an FDA-approved diabetes medication, is effective at enhancing immune responses to flu vaccine in older men and women. Participants will be randomly assigned to either metformin or placebo treatment for a total of 22 weeks. Participants will be vaccinated with high-dose flu vaccine after 12 weeks of treatment. Immune responses will be evaluated throughout the study at 6 time points.
As the global availability of vaccines increases, and reaches areas disproportionately affected by arsenic and malnutrition, resolving questions about potential environmental and biologic barriers to maternal immunization has become increasingly urgent. It is not known whether arsenic, a known developmental toxicant, can alter maternal immune responses to vaccination and whether exposure to arsenic during pregnancy can impair the transfer of maternal vaccine-induced antibody to the newborn. Moreover, factors known to affect arsenic metabolism and toxicity outcomes, particularly micronutrients critical in one-carbon metabolism, have not been evaluated in studies of arsenic immunotoxicity and vaccine-induced protection in mothers and their newborns. The objective in this study is to investigate whether maternal arsenic exposure and one-carbon metabolism micronutrient deficiencies alter maternal and newborn measures of vaccine-induced protection, respiratory morbidity, and systemic immune function following influenza vaccination during pregnancy.
Though HAV is mainly transmitted through the fecal-oral route, infection by sexual intercourse and blood transfusion is also possible. Injection drug users (IDUs) and men who have sex with men (MSM) have a higher risk of acquiring HAV due to their behaviors. Reemerging threat of hepatitis A among MSM in Taiwan has been reported recently. Based on the guidelines for the diagnosis and treatment of HIV/AIDS and the Advisory Committee on Immunization Practices (ACIP), Taiwan, vaccination of individuals against HAV with any of the following indications is recommended: HIV patients, adults with chronic hepatic disease, hemophilia, liver transplantation, occupational exposure, MSM, persons who use injection or noninjection illicit drugs, or persons traveling to or working in countries that have endemicity of HAV. In HIV-infected patients, the immunogenicity to HAV vaccination is sub-optimal in HIV-infected patients and the seroconversion rate is estimated 68-90% after administration of 2 or 3 doses of HAV vaccine. Furthermore, the antibody titers of HIV-infected patients following HAV vaccination are significantly lower compared to those of HIV-uninfected persons. The sub-optimal response among HIV-infected subjects remains an unresolved problem. In this study, the investigators aim to determine the to conduct a randomized clinical trial to compare the immunogenicity of 2 different doses of HAV vaccination (1 dose versus 2 doses) in HIV-infected patients who failed to achieve serologic response in the primary vaccination. This proposal will provide the solid evidence to elucidate the role of booster HAV vaccination in HIV-infected patients without response to primary HAV vaccination.
To determine whether metformin (MET) can improve the immune response to the pneumococcal conjugate vaccine (PCV-13) in older adults.
Environmental Enteropathy (EE) is an acquired sub-clinical inflammatory gut condition in which alterations in intestinal structure, function, and local and systemic immune activation lead to impaired vaccine responses, decreased cognitive potential and undernutrition in low-middle income countries. Approximately half of all global deaths in children aged less than five years are attributable to undernutrition making the study of EE an area of critical priority. However, given the operational limitations and ethical considerations for safely obtaining intestinal biopsies from young children in low resource settings, there have been few detailed investigations of human intestinal tissue in this vulnerable patient group for whom reversal of EE would provide the greatest benefit. EE biomarkers have been studied in different settings but these have not been correlated with the gold standard histopathology confirmation. The Study of Environment Enteropathy and Malnutrition in Pakistan (SEEM Pakistan) is designed to better understand the pathophysiology, predictors, biomarkers, and potential management strategies of EE to inform strategies to eradicate this debilitating pathology.
The following observational study will investigate whether the vaccine response (antibodies, T and B cells) after allogeneic stem cell transplantation is influenced by genetic polymorphisms in the interferon lambda signal.
This study evaluates seroconversion against measles, mumps, rubella and yellow fever following vaccination. One-third of children will receive both yellow fever and measles, mumps, and rubella (MMR) vaccines on the same day; one- third of children will receive MMR vaccine at enrollment followed by yellow fever vaccine 4 weeks later; one-third of children will receive yellow fever vaccine at enrollment followed by MMR vaccine 4 weeks later.
Rotavirus is the leading cause of diarrhea in children worldwide. Oral rotavirus vaccines work remarkably well in high-income countries, but for unclear reasons they underperform in low-income countries. A double-blind, randomized control trial will be performed to evaluate whether using a higher dose of a currently licensed vaccine (Rotarix, GlaxoSmithKline) can improve immune responses among infants in Dhaka, Bangladesh. Infants will be randomized 1:1 to receive either a standard or a double dose of Rotarix at 6 and 10 weeks of life. Infants will be assessed for fecal vaccine shedding and serum rotavirus-specific IgA responses to determine vaccine immunogenicity.
The purpose of this is that the researcher can use low power Near Infrared laser treatment non-painful and non-damaging dose to changes the skin properties.The researcher can prove that signaling and a significant increase in the number of skin cells in skin tissue exposed to the laser can improve the human skin immune system to help improve human body response to vaccines.