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Biomedical subjects

L K Ball

Publications and source records attributed to L K Ball.

9 recordsLinked to original sources
PubMed2001

Evaluating the immune response to combination vaccines.

Assessment of the immune responses to combination vaccines in the United States has generally been based on randomized, controlled comparative trials, with such studies designed to rule out predefined differences. In designing clinical studies of the immune response to combination products, attention should be directed toward selecting the appropriate immunologic end points and control groups. Acceptable differences in immune responses between combination and control groups should be predefined, and an adequate statistical plan should be developed. In many cases, it may be necessary to evaluate simultaneous administration of other recommended vaccines, assess schedule changes for 1 or more components of a combination, and bridge immunologic data obtained from international studies to the population of the United States. We discuss the use of immunogenicity studies to support the licensure of combination vaccines when field efficacy studies are either not possible or not required and highlight some recent experiences with combination vaccines containing Haemophilus influenzae type b polysaccharide conjugates.

Antibodies, Bacterial↗
PubMed2001

Current status and future trends in vaccine regulation--USA.

In regulating vaccines, the US Food and Drug Administration (FDA) is governed by the Code of Federal Regulations. These regulations serve as the framework for product characterization, as well as preclinical and clinical testing strategies. Novel vaccine approaches such as combination vaccines, vectored vaccines, new adjuvants, and novel delivery systems pose unique regulatory challenges for the FDA. If US licensure is sought, communication with the FDA throughout the clinical development of a product is essential to identify and implement the appropriate strategies for demonstrating the safety and effectiveness of a new product.

Adjuvants, Immunologic↗
PubMed2001

Stevens-Johnson syndrome and toxic epidermal necrolysis after vaccination: reports to the vaccine adverse event reporting system.

We conducted a telephone survey of reports of Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) to the Vaccine Adverse Event Reporting System. We identified six cases of SJS or TEN after vaccination without other obvious triggers, suggesting that SJS and TEN might very rarely be caused by vaccination. Confirmation of this hypothesis will likely require controlled studies.

Adult↗
PubMed2001

An assessment of thimerosal use in childhood vaccines.

BACKGROUND: On July 7, 1999, the American Academy of Pediatrics and the US Public Health Service issued a joint statement calling for removal of thimerosal, a mercury-containing preservative, from vaccines. This action was prompted in part by a risk assessment from the Food and Drug Administration that is presented here. METHODS: The risk assessment consisted of hazard identification, dose-response assessment, exposure assessment, and risk characterization. The literature was reviewed to identify known toxicity of thimerosal, ethylmercury (a metabolite of thimerosal) and methylmercury (a similar organic mercury compound) and to determine the doses at which toxicity occurs. Maximal potential exposure to mercury from vaccines was calculated for children at 6 months old and 2 years, under the US childhood immunization schedule, and compared with the limits for mercury exposure developed by the Environmental Protection Agency (EPA), the Agency for Toxic Substance and Disease Registry, the Food and Drug Administration, and the World Health Organization. RESULTS: Delayed-type hypersensitivity reactions from thimerosal exposure are well-recognized. Identified acute toxicity from inadvertent high-dose exposure to thimerosal includes neurotoxicity and nephrotoxicity. Limited data on toxicity from low-dose exposures to ethylmercury are available, but toxicity may be similar to that of methylmercury. Chronic, low-dose methylmercury exposure may cause subtle neurologic abnormalities. Depending on the immunization schedule, vaccine formulation, and infant weight, cumulative exposure of infants to mercury from thimerosal during the first 6 months of life may exceed EPA guidelines. CONCLUSION: Our review revealed no evidence of harm caused by doses of thimerosal in vaccines, except for local hypersensitivity reactions. However, some infants may be exposed to cumulative levels of mercury during the first 6 months of life that exceed EPA recommendations. Exposure of infants to mercury in vaccines can be reduced or eliminated by using products formulated without thimerosal as a preservative.

Animals↗
PubMed2001

Thiomersal in vaccines: is removal warranted?

The mercury-based vaccine preservative thiomersal has come under scrutiny in recent months because of its presence in certain vaccines that provide the foundation of childhood immunisation schedules. Over the past decade new vaccines have been added to the recommended childhood schedule, and the relatively smaller bodyweight of infants has led to concern that the cumulative exposure of mercury from infant vaccines may exceed certain guidelines for the human consumption of mercury. In the US, government agencies and professional societies have recently recommended that thiomersal be removed altogether from vaccines. Some involved in developing vaccine policy feel that the evidence to support these safety concerns has not risen to the level required for such a response. This apparent divergence of opinion has left healthcare professionals and the public with uncertainty about the potential health effects from low level exposure to thiomersal as well as the necessity of removing thiomersal from vaccines. At present, scientific investigation has not found conclusive evidence of harm from thiomersal in vaccines. As a precautionary measure, efforts are under way to remove or replace thiomersal from vaccines and providers should anticipate the availability of more vaccine products that are thiomersal-free over the coming years.

Child↗
PubMed2000

Hepatitis C.

Explore the source record for details and available documents.

Centers for Disease Control and Prevention, U.S.↗
PubMedDate not supplied

Should the vaccine injury compensation program be expanded to cover adults?

In 1996, the National Vaccine Advisory Committee (NVAC) asked for a review of the pros and cons of including adult influenza and pneumococcal vaccines in the Vaccine Injury Compensation Program (VICP). The authors, as staff to the subcommittees charged with undertaking this assessment, looked at the following questions: (a) Would inclusion in VICP of these two vaccines, used primarily for adults, increase adult vaccination levels? (b) Is this Federal involvement warranted based on the liability burden for these vaccines? (c) Does the risk of adverse events following vaccinations warrant inclusion of these vaccines? (d) Is there a consensus among stakeholders favoring their inclusion? To address these questions, the authors reviewed information on adult vaccines, including data on l lawsuits filed and reports of injuries, and sought input from interested groups. They found no evidence that the use of influenza and pneumococcal vaccines would increase if they were included in VICP. They found a low liability burden for these vaccines, that serious adverse events were rare, and that no consensus existed among stakeholders. After considering the staff report, NVAC chose, in 1996, not to advise the Department of Health and Human Services to include adult vaccines in VICP.

Adult↗