Revaccination with Live Attenuated Vaccines Confer Additional Beneficial Nonspecific Effects on Overall Survival: A Review
نویسندگان
چکیده
BACKGROUND Live vaccines against measles (MV), tuberculosis (BCG), polio (OPV) and smallpox reduce mortality more than explained by target-disease prevention. The beneficial nonspecific effects (NSEs) of MV are strongest when MV is given in presence of maternal antibodies. We therefore hypothesised that revaccination in presence of prior immunity enhances beneficial NSEs. METHODS Literature search for studies of revaccination and mortality. FINDINGS In two randomised trials (RCTs), two doses versus one dose of MV reduced all-cause mortality by 63% (95% CI: 23-83%) from 9 to 18months of age. In a quasi-experimental study two doses before and after 9months compared with one dose of MV after 9months of age reduced mortality by 59% (25-81%). BCG-revaccination significantly enhanced BCG's effect against overall child mortality in two RCTs. In a natural experiment study of OPV campaigns over a 13-year-period in Guinea-Bissau, each additional dose of OPV was associated with a 13% (4-21%) reduction in mortality rate. The beneficial NSEs of smallpox vaccination for survival increased significantly with the number of smallpox vaccination scars. INTERPRETATION Revaccination with live vaccines led to substantial reductions in overall mortality. These findings challenge current understanding of vaccines and may explain the beneficial effects of campaigns with live vaccines.
منابع مشابه
An overview on Leishmania vaccines: A narrative review article
Leishmaniasis is one of the major health problems and categorized as a class I disease (emerging and uncontrolled) by World Health Organization (WHO), causing highly significant morbidity and mortality. Indeed, more than 350 million individuals are at risk of Leishmania infection, and about 1.6 million new cases occur causing more than 50 thousands death annually. Because of the severe...
متن کاملVaccine design based on Live attenuated cells of Toxoplasma gondii: a review
Toxoplasma gondii is well- known as a common parasite with high proliferative activity in the nucleated cells. This parasite has infected nearly one third of the people worldwide. Infection can result in chorioretinitis in immunocompetent hosts, encephalitis in HIV/AIDS positive patients and abortion and neonatal loss in congenital toxoplasmosis. Development of vaccines for toxoplasmosis infect...
متن کامل[The use of tularemia live vaccine in clinical oncology].
ne of the methods of the active nonspecific antitumor immunity stimulation of cancer patients is application of bacterial antigens, from which in the past BCG vaccine was the most widely adopted (1). However, this vaccine has rather variable and short-term effects (2) that need the revaccination, whereas multiple applications of the vaccine undesirably increases the activity of suppressors and ...
متن کاملEvaluation of Live Attenuated Measles Vaccines Prepared in Human Diploid Cells for Reimmunization
متن کامل
Cross-protective immunity against leptospirosis elicited by a live, attenuated lipopolysaccharide mutant.
BACKGROUND Leptospira species cause leptospirosis, a zoonotic disease found worldwide. Current vaccines against leptospirosis provide protection only against closely related serovars. METHODS We evaluated an attenuated transposon mutant of Leptospira interrogans serovar Manilae (M1352, defective in lipopolysaccharide biosynthesis) as a live vaccine against leptospirosis. Hamsters received a s...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره 10 شماره
صفحات -
تاریخ انتشار 2016