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Helena Käyhty

Bio: Helena Käyhty is an academic researcher from National Institutes of Health. The author has contributed to research in topics: Vaccination & Pneumococcal conjugate vaccine. The author has an hindex of 57, co-authored 203 publications receiving 11805 citations. Previous affiliations of Helena Käyhty include Emory University & National Institute for Health and Welfare.


Papers
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Journal ArticleDOI
TL;DR: The heptavalent pneumococcal polysaccharide-CRM197 conjugate vaccine is safe and efficacious in the prevention of acute otitis media caused by the serotypes included in the vaccine.
Abstract: Background Ear infections are a common cause of illness during the first two years of life. New conjugate vaccines may be able to prevent a substantial portion of cases of acute otitis media caused by Streptococcus pneumoniae. Methods We enrolled 1662 infants in a randomized, double-blind efficacy trial of a heptavalent pneumococcal polysaccharide conjugate vaccine in which the carrier protein is the nontoxic diphtheria-toxin analogue CRM197. The children received either the study vaccine or a hepatitis B vaccine as a control at 2, 4, 6, and 12 months of age. The clinical diagnosis of acute otitis media was based on predefined criteria, and the bacteriologic diagnosis was based on a culture of middle-ear fluid obtained by myringotomy. Results Of the children who were enrolled, 95.1 percent completed the trial. With the pneumococcal vaccine, there were more local reactions than with the hepatitis B vaccine but fewer than with the combined whole-cell diphtheria–tetanus–pertussis and Haemophilus influenzae t...

1,466 citations

Journal ArticleDOI
TL;DR: A review of the evidence supporting pneumococcal carriage at the individual level as an immediate and necessary precursor to pneumonia disease is provided in this article, where the authors emphasize the role of information on vaccine carriage in vaccine trials and in public health decision-making.
Abstract: Streptococcus pneumoniae (pneumococcus) is a major cause of worldwide mortality and morbidity, and to a large extent is vaccine-preventable. Nasopharyngeal carriage of pneumococcus precedes disease and is the source of pneumococcal spread between people. The use of vaccine effect on carriage as part of the vaccine licensure and post-vaccine introduction evaluation could facilitate and expand the licensure of new, life-saving pneumococcal vaccines and enable a comprehensive estimate of population effects after vaccine introduction. The authors provide a review of the evidence supporting pneumococcal carriage at the individual level as an immediate and necessary precursor to pneumococcal disease. Based on such a causal link between carriage and disease, the authors emphasize the role of information on pneumococcal carriage in vaccine trials and in public health decision-making.

524 citations

Journal ArticleDOI
04 Jul 2003-Vaccine
TL;DR: This report analyses the various options with their relative merits and drawbacks and provides preliminary recommendations as guidance to regulatory agencies in evaluating these vaccines for the purposes of licensure.

350 citations

Journal ArticleDOI
TL;DR: Analysis of paired serum samples from 514 vaccinated children showed that effective immunization with this vaccine could be performed after but not before the age of 16 to 20 months, and 60 per cent of infections occurring in Finland over a period of five years are potentially preventable with the capsular polysaccharide vaccine.
Abstract: A long-term follow-up of approximately 50,000 children who received the Hemophilus influenzae type b capsular polysaccharide vaccine in 1974 at three months to five years of age has shown good protective efficacy in those who received the vaccine at 18 months or older. No adverse effects were observed. Analysis of paired serum samples from 514 vaccinated children showed that effective immunization with this vaccine could be performed after but not before the age of 16 to 20 months. An analysis of 956 bacteremic H. influenzae infections occurring in Finland over a period of five years showed that 94 per cent of all cases were in children under 10 years of age. Of these, 40 per cent occurred in children under 18 months, and 60 per cent in children between the ages of 1 1/2 and 9 years. These 60 per cent are potentially preventable with the capsular polysaccharide vaccine.

335 citations

Journal ArticleDOI
TL;DR: A new conjugate vaccine consisting of the capsular polysaccharide of H. influenzae type b covalently linked to a protein carrier (PRP-D), administered to infants beginning at the age of 3 months, is highly effective in protecting young Finnish children (7 to 24 months old) against invasive H. Influenzaetype b infections.
Abstract: Background. Haemophilus influenzae type b is the leading cause of invasive bacterial disease in young children. The capsular polysaccharide vaccine does not protect children at greatest risk (those under the age of 18 months), but a polysaccharide—protein conjugate vaccine has proved to be more immunogenic in this age group. Methods. We enrolled 114,000 infants in Finland in an open, prospective, randomized trial of a H. influenzae type b capsular polysaccharide—diphtheria toxoid conjugate vaccine (polyribosylribitol phosphate—diphtheria toxoid [PRP-D]). Children born on odd-numbered days were vaccinated at the ages of 3, 4, 6, and 14 to 18 months; those born on even-numbered days formed the control group and received the same vaccine at the age of 24 months. Results. After three doses of the vaccine there were 4 cases of verified bacteremic H. influenzae type b disease in the group receiving early vaccination, as compared with 64 cases in the control group, between the ages of approximately 7 an...

320 citations


Cited by
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Journal ArticleDOI
TL;DR: The Wyeth Lederle as discussed by the authors determined the efficacy, safety and immunogenicity of the CRM197 pneumococcal conjugate vaccine against invasive disease caused by vaccine serotypes and to determine the effectiveness of this vaccine against clinical episodes of otitis media.
Abstract: Objective.To determine the efficacy, safety and immunogenicity of the heptavalent CRM197 pneumococcal conjugate vaccine against invasive disease caused by vaccine serotypes and to determine the effectiveness of this vaccine against clinical episodes of otitis media.Methods.The Wyeth Lederle

2,204 citations

Journal ArticleDOI
TL;DR: The use of the pneumococcal conjugate vaccine is preventing disease in young children, for whom the vaccine is indicated, and may be reducing the rate of disease in adults.
Abstract: Background In early 2000, a protein–polysaccharide conjugate vaccine targeting seven pneumococcal serotypes was licensed in the United States for use in young children. Methods We examined population-based data from the Active Bacterial Core Surveillance of the Centers for Disease Control and Prevention to evaluate changes in the burden of invasive disease, defined by isolation of Streptococcus pneumoniae from a normally sterile site. Serotyping and susceptibility testing of isolates were performed. We assessed trends using data from seven geographic areas with continuous participation from 1998 through 2001 (population, 16 million). Results The rate of invasive disease dropped from an average of 24.3 cases per 100,000 persons in 1998 and 1999 to 17.3 per 100,000 in 2001. The largest decline was in children under two years of age. In this group, the rate of disease was 69 percent lower in 2001 than the base-line rate (59.0 cases per 100,000 vs. 188.0 per 100,000, P<0.001); the rate of disease caused by va...

2,135 citations

Journal ArticleDOI
TL;DR: The mechanism and epidemiology of colonisation, the complexity of relations within and between species, and the consequences of the different preventive strategies for pneumococcal colonisation are discussed.
Abstract: Streptococcus pneumoniae is an important pathogen causing invasive diseases such as sepsis, meningitis, and pneumonia. The burden of disease is highest in the youngest and oldest sections of the population in both more and less developed countries. The treatment of pneumococcal infections is complicated by the worldwide emergence in pneumococci of resistance to penicillin and other antibiotics. Pneumococcal disease is preceded by asymptomatic colonisation, which is especially high in children. The current seven-valent conjugate vaccine is highly effective against invasive disease caused by the vaccine-type strains. However, vaccine coverage is limited, and replacement by non-vaccine serotypes resulting in disease is a serious threat for the near future. Therefore, the search for new vaccine candidates that elicit protection against a broader range of pneumococcal strains is important. Several surface-associated protein vaccines are currently under investigation. Another important issue is whether the aim should be to prevent pneumococcal disease by eradication of nasopharyngeal colonisation, or to prevent bacterial invasion leaving colonisation relatively unaffected and hence preventing the occurrence of replacement colonisation and disease. To illustrate the importance of pneumococcal colonisation in relation to pneumococcal disease and prevention of disease, we discuss the mechanism and epidemiology of colonisation, the complexity of relations within and between species, and the consequences of the different preventive strategies for pneumococcal colonisation.

1,770 citations

Journal ArticleDOI
TL;DR: The SHSIP provides a well-detailed description of the proposed value-based models of care through the Patient-Centered Medical Home (PCMH) model, resulting in the statewide implementation of Accountable Health Communities (AHCs).
Abstract: Vision for Transformation Strengths: The SHSIP describes a holistic transformation plan and ensures connections between various plan components. The State’s Plan seeks to reward health care providers for better care, smarter spending, and healthier people through higher quality, instead of quantity of services by utilizing valuebased purchasing across public and private payers. The SHSIP provides a well-detailed description of the proposed value-based models of care through the Patient-Centered Medical Home (PCMH) model, resulting in the statewide implementation of Accountable Health Communities (AHCs). The SHSIP outlines a long-term vision of building and expanding the PCMH model into a Community Centered Health Homes (CCHHs) model, which will focus on prevention and collaboration with other communitybased organizations. Another strength identified is the amount of existing PCMHs operating within the State. The SHSIP provides a course of action to assist non-PCMH practices to become nationally certified, as well as, goals for a single, statewide PCMH model to be used by all providers and payers within the state. The implementation of the AHCs will be key in addressing social determinants of health within various communities and seems to align well with the PCMH goals. This focus on population and community health will enable the State to make a broader impact and support the long-term goal of moving towards a CCHH model. The focus on the improvement of clinical, behavioral, and oral health care within the urban, rural, and frontier communities is well aligned and consistent with the SIM goals and the overall Triple Aim initiative. Figure 18: Driver Diagram clearly shows how the State plans to achieve the Triple Aim by 2020.

1,627 citations

Journal ArticleDOI
TL;DR: The heptavalent pneumococcal polysaccharide-CRM197 conjugate vaccine is safe and efficacious in the prevention of acute otitis media caused by the serotypes included in the vaccine.
Abstract: Background Ear infections are a common cause of illness during the first two years of life. New conjugate vaccines may be able to prevent a substantial portion of cases of acute otitis media caused by Streptococcus pneumoniae. Methods We enrolled 1662 infants in a randomized, double-blind efficacy trial of a heptavalent pneumococcal polysaccharide conjugate vaccine in which the carrier protein is the nontoxic diphtheria-toxin analogue CRM197. The children received either the study vaccine or a hepatitis B vaccine as a control at 2, 4, 6, and 12 months of age. The clinical diagnosis of acute otitis media was based on predefined criteria, and the bacteriologic diagnosis was based on a culture of middle-ear fluid obtained by myringotomy. Results Of the children who were enrolled, 95.1 percent completed the trial. With the pneumococcal vaccine, there were more local reactions than with the hepatitis B vaccine but fewer than with the combined whole-cell diphtheria–tetanus–pertussis and Haemophilus influenzae t...

1,466 citations