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Larry K Pickering

Publications and source records attributed to Larry K Pickering.

15 recordsLinked to original sources

Noroviruses bind to human ABO, Lewis, and secretor histo-blood group antigens: identification of 4 distinct strain-specific patterns.

We characterized the binding of 8 Noroviruses (NORs) to histo-blood group antigens (HBGAs) in human saliva using recombinant NOR (rNOR) capsid proteins. Among the 8 rNORs tested, 6 formed viruslike particles (VLPs) when the capsid proteins were expressed in insect cells, all of which revealed variable binding activities with saliva; the remaining 2 rNORs did not form VLPs, and the proteins did not bind, or bound weakly, to saliva. Four distinct binding patterns were associated with different histo-blood types, defined by Lewis, secretor, and ABO types. Three patterns (VA387, NV, and MOH) recognized secretors, and 1 pattern (VA207) recognized Lewis-positive nonsecretors. The 3 secretor-recognizing patterns were defined as A/B (MOH), A/O (NV), and A/B/O (VA387) binders. Oligosaccharides containing the Lewis and ABH antigenic epitopes were involved in binding. Our findings suggest that different strains of NORs may recognize different human HBGAs on intestinal epithelial cells as receptors for infection.

ABO Blood-Group System↗

Comparison of e-mail, fax, and postal surveys of pediatricians.

OBJECTIVES: To compare 3 communication modes (postal, fax, and e-mail) in a rotavirus vaccine physician survey. METHODS: We used 3 communication modes to distribute a survey to physicians listed in the membership directory of the Georgia Chapter of the American Academy of Pediatrics. The directory listed 1391 members; however, 404 were deemed ineligible on the basis of their listing as a specialist, retiree, resident in training, or government public health employee. Of the 987 members expected to administer vaccines, 150 were selected randomly to receive the postal survey (postal group). Of the remaining listings, 488 (58%) of 837 listed a fax number; 150 members were selected randomly and faxed a survey (fax group). Of the remaining members, 266 (39%) of 687 had e-mail addresses listed; 150 members were selected randomly for the e-mail survey (e-mail group). A follow-up survey was sent by the same mode at 2 weeks. A final survey was sent via another mode (mixed mode) at 1 month: by fax to e-mail and postal nonresponders and by post to fax nonresponders and those without fax. RESULTS: Eligible respondents in the 3 survey groups were similar in their practice setting and location. Although the e-mail group had fewer median years (8 years) since medical school graduation than the fax group (19 years) and postal group (17 years), a similar percentage of responders in all groups had computers (>85%) and Internet access (> or =70%) at work. However, only 39% of members listed an e-mail address in the directory. In the 2 weeks after the first mailing, 39 surveys were completed via postal mail, 50 via fax, and 16 via e-mail. In the 2 weeks after the second contact (sent at 2 weeks), 20 surveys were completed via postal mail, 15 via fax, and 17 via e-mail. The response rate after the first 2 mailings was 41% (59 of 143) for postal, 47% (65 of 137) for fax, and 26% (33 of 125) for e-mail surveys. The third and final survey (sent 1 month after the first mailing) was sent by a different (ie, mixed) mode and elicited an additional 73 responses: 19 responses (15 postal, 4 fax) from the postal group, 19 responses (18 postal, 1 fax) from the fax group, and 35 responses (15 postal, 13 fax, 7 e-mail) from the e-mail group. Twenty-three percent (9 of 40) of the e-mail and 18% (15 of 83) of the fax surveys completed were returned on the same or subsequent day they were sent, compared with none of the postal surveys. There were significant differences among the 3 groups for invalid addresses/numbers (4% postal, 8% fax, and 16% e-mail) listed in the directory. Using mixed modes as the third contact, the overall response rate increased from 39% before mixed mode to a final of 53%. On the basis of the 3 initial groups, responses to 1 of 12 rotavirus questions differed significantly. CONCLUSIONS: Future use of e-mail surveys in selected circumstances is promising, because the majority of providers have Internet access and acknowledged interest in participating in e-mail surveys. E-mail surveys could be especially useful if rapid response time is necessary. There were fewer incomplete questions by participants who completed the e-mail survey compared with postal or fax participants. Updating membership e-mail addresses and routinely using e-mail as a communication tool should improve the ability to use e-mail surveys. There may need to be ongoing evaluations that critically evaluate providers' responses to e-mail surveys compared with other survey modes before e-mail surveys can become a standard survey tool. In the meantime, mixed-mode surveys may be an option.

Cross-Sectional Studies↗

Human milk secretory antibodies against attaching and effacing Escherichia coli antigens.

Secretory immunoglobulin A (sIgA) is a primary factor responsible for preventing attachment of enteropathogens to gut epithelium in breastfeeding infants. We compared the frequency of sIgA to major surface antigens of enterohemorrhagic Escherichia coli (EHEC) in milk of 123 women from the United States and Mexico to determine whether regional differences existed in the frequency of antibodies to these surface antigens. In both groups of women, milk commonly has sIgA against various EHEC lipopolysaccharides, EspA, EspB, intimin, and less frequently against Shiga toxin. The study suggests that persons living in the United States are exposed to attaching/effacing enteropathogens more frequently than is generally assumed. The low frequency of antibodies to Stx1 (in 12% of Mexican and in 22% of U.S. samples) suggests that the rare appearance of hemolytic uremic syndrome in adults is not due to neutralization of toxin at the gut level. Only anti-EspA is found in most milk samples from both populations of women. EspA may represent a useful target for an immunization strategy to prevent EHEC disease in humans.

Adult↗

General recommendations on immunization. Recommendations of the Advisory Committee on Immunization Practices (ACIP) and the American Academy of Family Physicians (AAFP).

This report is a revision of General Recommendations on Immunization and updates the 1994 statement by the Advisory Committee on Immunization Practices (ACIP) (CDC. General recommendations on immunization: recommendations of the Advisory Committee on Immunization Practices [ACIP]. MMWR 1994;43[No. RR-1]:1-38). The principal changes include expansion of the discussion of vaccination spacing and timing, recommendations for vaccinations administered by an incorrect route, information regarding needle-free injection technology, vaccination of children adopted from countries outside the United States, timing of live-virus vaccination and tuberculosis screening, expansion of the discussion and tables of contraindications and precautions regarding vaccinations, and addition of a directory of immunization resources. These recommendations are not comprehensive for each vaccine. The most recent ACIP recommendations for each specific vaccine should be consulted for additional details. This report, ACIP recommendations for each vaccine, and other information regarding immunization can be accessed at CDCs National Immunization Program website at http.//www.cdc.gov/nip (accessed October 11, 2001).

Adolescent↗

Development of pediatric vaccine recommendations and policies.

A significant decrease in each vaccine-preventable disease has occurred since the introduction of the respective immunizations now included in the recommended childhood immunization schedule. The process through which a vaccine must travel from development to approval and implementation is complex. Hurdles include receiving approval from several advisory committees, government agencies, and professional organizations. At each step in the process, data regarding safety, immunogenicity, and efficacy are evaluated continuously and rigorously. Once a vaccine is approved by the Food and Drug Administration (FDA) and incorporated into the recommended childhood immunization schedule, continuing issues include those that deal with supply, safety, effectiveness, and financing. The logistics of development and implementation of pediatric vaccine recommendations and policies are reviewed.

Advisory Committees↗

Immune status of infants fed soy-based formulas with or without added nucleotides for 1 year: part 1: vaccine responses, and morbidity.

BACKGROUND: Immunologic development of soy-fed infants has not been extensively studied. Early studies of soy flour-based formulas showed decreased immunoglobulin production when soy protein intake was limited. However, there were no significant differences in rotavirus vaccine responses between breast-fed and soy protein isolate-based formula-fed infants. Nucleotides added to milk-based formula benefit infant immune status, but reports of the immunologic effects of adding nucleotides to soy-based formula are not available. This study evaluated immune status and morbidity of infants fed soy protein isolate formulas with and without added nucleotides for 1 year. METHODS: Newborn, term infants enrolled in a masked 12-month feeding trial were assigned randomly to groups fed soy formula with or without added nucleotides (n = 94, n = 92). A nonrandomized human milk/formula cohort (n = 81) was concurrently enrolled. Recommended immunizations were administered at 2, 4, and 6 months. Immune status was determined from antibody responses to Haemophilus influenzae type b, tetanus, diphtheria, and poliovirus vaccines at 6, 7, and 12 months. Parents and physicians reported morbidity data. RESULTS: All vaccine responses were within normal ranges. No response differences were observed between infants fed soy formula and those fed nucleotide-supplemented soy. However, antibody to H. influenzae type b at 7 and 12 months was higher in infants fed nucleotide-supplemented soy than in infants fed human milk/formula ( P = 0.007, P = 0.008, respectively). Human milk/formula-fed infants had higher poliovirus neutralizing antibody at 12 months than did soy-fed infants ( P = 0.016). Morbidity analyses showed that only physician-reported diarrhea was different among groups (groups fed human milk/formula had less diarrhea than did soy groups, P = 0.011). CONCLUSIONS: Term infants fed soy protein isolate-based formulas have normal immune development as measured by antibody responses to childhood immunizations.

Antibody Formation↗

Immune status of infants fed soy-based formulas with or without added nucleotides for 1 year: part 2: immune cell populations.

BACKGROUND: Infants fed a soy protein isolate-based formula have immunization responses similar to breast-fed infants. However, cellular aspects of the immunologic development of soy-fed infants have not been studied extensively. Nucleotides added to milk-based formula benefit infant immune status, but reports of the immunologic effects of adding nucleotides to soy-based formula are not available. This study examines immune cell populations of infants fed soy protein isolate formulas with and without added nucleotides for 1 year. METHODS: Newborn, term infants studied in a masked 12-month feeding trial were assigned randomly to soy formula groups with and without added nucleotides (n = 94, n = 92). A nonrandomized human milk/formula-fed cohort (n = 81), was concurrently enrolled. Blood samples were collected at 6, 7, and 12 months. Thirty-two immune cell populations were characterized using three-color flow cytometry. Cellular markers were chosen to assess general pediatric immune status, emphasizing maturation and activation of B, T, and NK lymphocytes. RESULTS: All cell populations, number and percentages, were within age-related normal ranges. The only significant difference found between soy formula and human milk/formula-fed infants was the percentage of CD57 + NK T cells at 12 months (human milk/formula > soy formula, P = 0.034). There were significant differences at some time points between human milk/formula-fed and nucleotide-supplemented soy formula-fed infants in populations of lymphocytes, eosinophils, total T, helper T, naive helper, memory/effector helper, CD57 - T, and CD11b + CD8 + NK cells. None of the cell populations differed between infants fed soy formula versus soy plus nucleotides. CONCLUSIONS: Infants fed this commercial soy formula demonstrated immune cell status similar to human milk/formula-fed infants, consistent with normal immune system development. The addition of nucleotides to soy formula did not significantly change specific individual immune cell populations but tended to increase numbers and percentages of T cells and decreased numbers and percentages of NK cells.

B-Lymphocytes↗

Clinical presentations of rotavirus infection among hospitalized children.

BACKGROUND: Although rotaviruses (RVs) are the most common cause of severe gastroenteritis in children, there is a lack of information detailing the spectrum of clinical manifestations of RV disease resulting in hospitalization. OBJECTIVE: To characterize the clinical spectrum of RV-associated hospitalizations, including short stay visits in children. METHODS: Active RV disease surveillance was conducted at three children's hospitals Sundays through Thursdays in children 15 days through 4 years of age admitted with diarrhea (D), vomiting (V) and/or unexplained fever (F) between November, 1997, and June, 1998. Stool specimens were collected and tested for RV by enzyme immunoassay. RESULTS: Of the 862 children enrolled, 763 (88%) had a stool specimen tested for RV. Overall 31% of children excreted RV. RV excretion was highest when all 3 symptoms (D, V and F) occurred in the same child (56%), lower when 2 symptoms occurred together (38% DV; 19% DF; 13% VF) and lowest when each symptom occurred alone (3% D; 11% V; 6% F). Nine percent of the children without diarrhea excreted RV. Children admitted without diarrhea were more likely to have rotavirus if they developed diarrhea during their hospitalization. CONCLUSIONS: RV detection was greatest when diarrhea, vomiting and fever occurred together and lowest when each symptom occurred alone. The spectrum of symptoms of rotavirus disease in children at the time of admission to the hospital or short stay unit may be broader than previously recognized.

California↗

The potential of pneumococcal conjugate vaccines for children.

In contrast to earlier pneumococcal vaccines, conjugate vaccines hold promise for reducing pneumococcal morbidity and mortality in infants and young children. The first commercially available conjugate vaccine formulation, which targets seven serotypes, was licensed in the US and other countries in 2000; this vaccine is now part of routine infant immunization in the US. Demand has been high and greater than vaccine supply. Clinical trials indicate that conjugate vaccines are highly efficacious against invasive pneumococcal disease and modestly efficacious against otitis media and pneumonia. In carriage studies conjugate vaccines reduced vaccine-type carriage but led to an increase in carriage of other serotypes. Remaining questions include whether less frequent transmission of vaccine serotypes will mean less disease in unvaccinated children and adults or if nonvaccine serotypes will begin to cause more disease. Monitoring disease burden after widespread use in the US is critical for understanding the effects of the vaccine. In addition making pneumococcal vaccines available for children in developing countries should be a high priority.

Bacteremia↗

Interchangeability of 2 diphtheria-tetanus-acellular pertussis vaccines in infancy.

OBJECTIVE: Currently, 4 diphtheria-tetanus-acellular pertussis (DTaP) vaccines are licensed for pediatric use in the United States, and 2 are commercially available. Although a single manufacturer's DTaP vaccine should be used for all 3 doses of the primary immunization series, some circumstances result in infants receiving DTaP vaccines from more than 1 manufacturer. The purpose of this study was to evaluate the safety and immunogenicity of a mixed sequence of 2 different DTaP vaccines. METHODS: In this multicenter, observer-blinded, controlled study, 449 infants were randomized into 1 of 3 groups (1:1:1 ratio) to receive Tripedia at 2, 4, and 6 months of age (control group); Tripedia at 2 and 4 months of age and Infanrix at 6 months of age; or Tripedia at 2 months and Infanrix at 4 and 6 months of age. Other vaccines were administered concurrently as separate injections according to the recommended childhood immunization schedule. Safety was monitored closely, and standard enzyme immunoassays were used to measure antibody concentrations to each antigen of the DTaP vaccines. RESULTS: The rates of injection-site and systemic adverse events were similar in each study group, and there were no clinically significant differences among groups after any dose. Infants in all 3 groups responded well to each antigen contained in both vaccines, with 97% to 100% seroprotection or vaccine response rates after the 3-dose primary series. Postvaccination geometric mean antibody concentrations and seroprotection or vaccine response rates to nearly all vaccine antigens were as high or higher in the mixed-sequence groups as in the control group. CONCLUSION: Initiating the primary immunization series with 1 or 2 doses of Tripedia and completing the 3-dose series with Infanrix is as safe and at least as immunogenic as administering Tripedia for all 3 doses.

Antibodies↗

Timeliness of childhood immunizations.

OBJECTIVE: To examine the timeliness of vaccine administration among infants and young children in the United States. METHODS: We analyzed age at receipt of vaccines among 16 211 children aged 24 to 35 months in the 2000 National Immunization Survey and examined receipt at the recommended time of each dose and selected vaccination series, as well as receipt at 4 additional time frames: acceptably early, late, never by 24 months, and too early to be considered valid. We also examined the relationship between timeliness of vaccinations and characteristics of the child, mother, and immunization provider, using multivariate logistic regression. RESULTS: Only 9% of children received all recommended vaccines at the recommended ages. The rates varied significantly by antigen, ranging from 24% for all Haemophilus influenzae type b doses to 75% for all hepatitis B doses as recommended. Overall, 55% of children did not receive all recommended doses by 24 months of age, and 8% of children received at least 1 vaccination dose too early to be considered valid. Factors associated with not receiving all vaccines as recommended were having more children in the household, mothers younger than 30 years, use of public providers, and multiple vaccination providers. CONCLUSIONS: By 24 months of age, 9 of 10 children received at least 1 vaccine outside the recommended age ranges. High vaccination status of children at 24 months of age does not reflect the reality that many vaccinations are not given at the appropriate ages. Timeliness of vaccination is critical to prevent disease outbreaks, protect children through their first 2 years of life, and minimize the need to repeat doses.

Age Factors↗