Systemic fungal infections with primary and opportunistic pathogens have become increasingly common and represent a growing health menace in patients with AIDS and other immune deficiencies. T lymphocyte immunity, in particular the CD4 Th 1 cells, is considered the main defense against these pathogens, and their absence is associated with increased susceptibility. It would seem illogical then t...

Bordetella pertussis infection remains an important public health problem worldwide despite decades of routine vaccination. A key indicator of the impact of vaccination programmes is the inter-epidemic period, which is expected to increase with vaccine uptake if there is significant herd immunity. Based on empirical data from 64 countries across the five continents over the past 30-70 years, we...

Bordetella pertussis and Bordetella parapertussis are closely related endemic human pathogens which cause whooping cough, a disease that is reemerging in human populations. Despite how closely related these pathogens are, their coexistence and the limited efficacy of B. pertussis vaccines against B. parapertussis suggest a lack of cross-protective immunity between the two. We sought to address ...

Rhesus monkeys with experimental Plasmodium knowlesi infections of varying duration were treated with sodium sulfathiazole to sterilize the infection and after differing lengths of time were reinoculated intraperitoneally with homologous strains of the plasmodium, for the purpose of determining whether there is any acquired immunity to malaria in hosts from whom all parasites have been removed....

Global climate change is predicted to alter the distribution and dynamics of soil-transmitted helminth infections, and yet host immunity can also influence the impact of warming on host-parasite interactions and mitigate the long-term effects. We used time-series data from two helminth species of a natural herbivore and investigated the contribution of climate change and immunity on the long-te...

Human newborns and infants are bombarded with multiple pathogens on leaving the sterile intra-uterine environment, and yet have suboptimal innate immunity and limited immunological memory, thus leading to increased susceptibility to infections in early life. They are thus the target age group for a host of vaccines against common bacterial and viral pathogens. They are also the target group for...

The human immune system is the first line of defense in prevention viruses and diseases, several response mechanisms are engaged at onset a pathogenic attack. In this review, we elucidate as critical element protecting humans from COVID-19 by describing process, explaining how functions, highlighting system’s global importance fighting infections. Potential challenges that limit proper function...

Cells of Escherichia coli B infected with the immunity-negative (imm2) mutant of bacteriophage T4 are able to develop a substantial level of immunity to superinfecting phage ghosts if the ghost challenge is made late in infection. This background immunity is not seen in infections with phage carrying the spackle (s) mutation in addition to the imm2 lesion. The level of immunity in s(-) infectio...

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...

Evidence suggests that many Ebola infections are asymptomatic, a factor overlooked by recent outbreak summaries and projections. Particularly, results from one post-Ebola outbreak serosurvey showed that 71% of seropositive individuals did not have the disease; another study reported that 46% of asymptomatic close contacts of patients with Ebola were seropositive. Although asymptomatic infection...