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Charles J Hackett

Publications and source records attributed to Charles J Hackett.

5 recordsLinked to original sources
PubMed2003

Innate immune activation as a broad-spectrum biodefense strategy: prospects and research challenges.

Biodefense strategies require protection against a broad and largely unforeseen spectrum of pathogens--the forte of innate immune system defenses--that have evolved over millennia to function within moments of encountering either ancient or newly emerging pathogens. Although constitutive, the innate immune system is activated by the presence of microbes or their products, providing a rationale for a potential biodefense strategy. Both prophylactic and postexposure strategies involving innate immune stimulation have been shown to be plausible to prevent or ameliorate infections in animal models. Innate immune-activating compounds based on conserved microbial components recognized by toll-like molecules and other receptors could be synthesized and delivered like drugs by using an entirely different strategy from conventional vaccination. However, important theoretic and practical questions emerge about developing and deploying innate immune protective strategies for biodefense. This rostrum discusses prospects and problems in the overall approach itself. Important topics include microbe-specific issues about innate immune system effectiveness against highly virulent pathogens and general questions, such as whether innate immune responses will be safe and effective if used in a diverse human population of different age groups and with different genetic makeups.

Adaptation, Physiological↗
PubMed2003

Addressing parents' concerns: do vaccines cause allergic or autoimmune diseases?

Anecdotal case reports and uncontrolled observational studies in the medical literature claim that vaccines cause chronic diseases such as asthma, multiple sclerosis, chronic arthritis, and diabetes. Several biological mechanisms have been proposed to explain how vaccines might cause allergic or autoimmune diseases. For example, allergic diseases might be caused by prevention of early childhood infections (the "hygiene hypothesis"), causing a prolongation of immunoglobulin E-promoting T-helper cell type 2-type responses. However, vaccines do not prevent most common childhood infections, and large well-controlled epidemiologic studies do not support the hypothesis that vaccines cause allergies. Autoimmune diseases might occur after immunization because proteins on microbial pathogens are similar to human proteins ("molecular mimicry") and could induce immune responses that damage human cells. However, wild-type viruses and bacteria are much better adapted to growth in humans than vaccines and much more likely to stimulate potentially damaging self-reactive lymphocytes. Consistent with critical differences between natural infection and immunization, well-controlled epidemiologic studies do not support the hypothesis that vaccines cause autoimmunity. Flaws in proposed biological mechanisms that explain how vaccines might cause chronic diseases are consistent with the findings of many well-controlled large epidemiologic studies that fail to show a causal relationship.

Arthritis↗
PubMed2002

Addressing parents' concerns: do multiple vaccines overwhelm or weaken the infant's immune system?

Recent surveys found that an increasing number of parents are concerned that infants receive too many vaccines. Implicit in this concern is that the infant's immune system is inadequately developed to handle vaccines safely or that multiple vaccines may overwhelm the immune system. In this review, we will examine the following: 1) the ontogeny of the active immune response and the ability of neonates and young infants to respond to vaccines; 2) the theoretic capacity of an infant's immune system; 3) data that demonstrate that mild or moderate illness does not interfere with an infant's ability to generate protective immune responses to vaccines; 4) how infants respond to vaccines given in combination compared with the same vaccines given separately; 5) data showing that vaccinated children are not more likely to develop infections with other pathogens than unvaccinated children; and 6) the fact that infants actually encounter fewer antigens in vaccines today than they did 40 or 100 years ago.

Adult↗