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result(s) for
"Sandbulte, Matthew"
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Discordant antigenic drift of neuraminidase and hemagglutinin in H1N1 and H3N2 influenza viruses
2011
Seasonal epidemics caused by influenza virus are driven by antigenic changes (drift) in viral surface glycoproteins that allow evasion from preexisting humoral immunity. Antigenic drift is a feature of not only the hemagglutinin (HA), but also of neuraminidase (NA). We have evaluated the antigenic evolution of each protein in H1N1 and H3N2 viruses used in vaccine formulations during the last 15 y by analysis of HA and NA inhibition titers and antigenic cartography. As previously shown for HA, genetic changes in NA did not always lead to an antigenic change. The noncontinuous pattern of NA drift did not correspond closely with HA drift in either subtype. Although NA drift was demonstrated using ferret sera, we show that these changes also impact recognition by NA-inhibiting antibodies in human sera. Remarkably, a single point mutation in the NA of A/Brisbane/59/2007 was primarily responsible for the lack of inhibition by polyclonal antibodies specific for earlier strains. These data underscore the importance of NA inhibition testing to define antigenic drift when there are sequence changes in NA.
Journal Article
Using a Social Support Framework to Understand How HIV Positive Kenyan Men Engage in PMTCT/EID Care: Qualitative Insights From Male Partners
2020
Greater male partner involvement in Prevention of Mother to Child Transmission (PMTCT) and Early Infant Diagnosis (EID) is associated with improved outcomes. Perceived low social support for the mother can negatively impact the uptake of PMTCT/EID services. Most research relies on women’s reports of the types and quality of male partner support received versus what is desired. This qualitative study examines Kenyan male partners' reported social support provision pre- and post-partum from their own perspective. The study was embedded within intervention development studies in Kenya designed to develop and pilot a PMTCT module of a web based system to improve EID. Focus groups were conducted with male partners of pregnant women with HIV and elicited feedback on male partner involvement in maternal and child care and factors affecting participation. Interviews were analyzed within a theoretical social support framework. Participants described providing tangible support (financial resources), informational support (appointment reminders) and emotional support (stress alleviation in the face of HIV-related adversity). African conceptualizations of masculinity and gender norms influenced the types of support provided. Challenges included economic hardship; insufficient social support from providers, peers and bosses; and HIV stigma. Collaboration among providers, mothers and partners; a community-based social support system; and recasting notions of traditional masculinity were identified as ways to foster male partner support.
Journal Article
Optimal Use of Vaccines for Control of Influenza A Virus in Swine
by
Zaabel, Pamela
,
Roth, James
,
Sandbulte, Matthew
in
immune response
,
Immunization
,
Infectious diseases
2015
Influenza A virus in swine (IAV-S) is one of the most important infectious disease agents of swine in North America. In addition to the economic burden of IAV-S to the swine industry, the zoonotic potential of IAV-S sometimes leads to serious public health concerns. Adjuvanted, inactivated vaccines have been licensed in the United States for over 20 years, and there is also widespread usage of autogenous/custom IAV-S vaccines. Vaccination induces neutralizing antibodies and protection against infection with very similar strains. However, IAV-S strains are so diverse and prone to mutation that these vaccines often have disappointing efficacy in the field. This scientific review was developed to help veterinarians and others to identify the best available IAV-S vaccine for a particular infected herd. We describe key principles of IAV-S structure and replication, protective immunity, currently available vaccines, and vaccine technologies that show promise for the future. We discuss strategies to optimize the use of available IAV-S vaccines, based on information gathered from modern diagnostics and surveillance programs. Improvements in IAV-S immunization strategies, in both the short term and long term, will benefit swine health and productivity and potentially reduce risks to public health.
Journal Article
Interventions designed to increase scholarly activity and achieve promotion among primarily junior clinical faculty in the United States: a scoping review
by
Beck Dallaghan, Gary L.
,
Lowndes, Bethany R.
,
Valenta, Carrie
in
Academic medical centers
,
Academic Rank (Professional)
,
Activity Units
2025
Background
For many U.S. academic physicians, direct patient care is the primary focus of daily work and the most important professional responsibility. Concurrently, some degree of scholarly activity is often required for career advancement. Junior clinical faculty often face challenges that limit their success in this area such as heavy clinical workloads or other time constraints, a lack of personal expertise or experience, mentorship, and institutional infrastructure. Support systems and faculty development interventions may mitigate these challenges and contribute to increased academic productivity and promotion. The objective of this study was to perform a scoping review of literature on strategies which increase scholarly activity among junior clinical faculty in the United States to determine the extent to which this topic has been scientifically investigated, the form of the employed strategies for supporting junior clinical faculty scholarly activity, the types of scholarly activity measured, and the research methods used.
Methods
An online search of PubMed, CINAHL, Cochrane Library, Embase, ERIC and APA PsycINFO databases was conducted and supplemented by a manual search of references and citations. Articles published between January 1, 2012, and February 7, 2025, that described faculty development interventions designed to increase scholarly productivity of junior clinical faculty in the United States were included. We employed a structured data extraction algorithm, extracted data in dyads, and resolved any inconsistencies using a third extractor. Included publications were categorized by the primary intervention strategy they employed.
Results
Eighteen publications are included in this scoping review. The most common primary strategies for supporting scholarly activity were peer-mentoring (5/18, 28%) and traditional mentoring (5/18, 28%). Other strategies included grants and funding (4/18, 22%), faculty development and training (2/18, 11%), and protected time (1/18, 6%). Two of the 18 publications included a control group.
Conclusions
Mentoring was the most common strategy to support scholarly activity of junior clinical faculty followed by faculty development programs. Scholarly activity is often measured by publications, grant funding, and presentations. A major gap in the current literature is the absence of any high-quality research demonstrating a beneficial effect on the scholarly activity of junior clinical faculty.
Journal Article
Cross-Reactive Neuraminidase Antibodies Afford Partial Protection against H5N1 in Mice and Are Present in Unexposed Humans
by
Treanor, John J
,
Boon, Adrianus C. M
,
Webby, Richard J
in
Animals
,
Antibodies
,
Antibodies, Viral - immunology
2007
A pandemic H5N1 influenza outbreak would be facilitated by an absence of immunity to the avian-derived virus in the human population. Although this condition is likely in regard to hemagglutinin-mediated immunity, the neuraminidase (NA) of H5N1 viruses (avN1) and of endemic human H1N1 viruses (huN1) are classified in the same serotype. We hypothesized that an immune response to huN1 could mediate cross-protection against H5N1 influenza virus infection.
Mice were immunized against the NA of a contemporary human H1N1 strain by DNA vaccination. They were challenged with recombinant A/Puerto Rico/8/34 (PR8) viruses bearing huN1 (PR8-huN1) or avN1 (PR8-avN1) or with H5N1 virus A/Vietnam/1203/04. Additional naïve mice were injected with sera from vaccinated mice prior to H5N1 challenge. Also, serum specimens from humans were analyzed for reactivity with avN1. Immunization elicited a serum IgG response to huN1 and robust protection against the homologous challenge virus. Immunized mice were partially protected from lethal challenge with H5N1 virus or recombinant PR8-avN1. Sera transferred from immunized mice to naïve animals conferred similar protection against H5N1 mortality. Analysis of human sera showed that antibodies able to inhibit the sialidase activity of avN1 exist in some individuals.
These data reveal that humoral immunity elicited by huN1 can partially protect against H5N1 infection in a mammalian host. Our results suggest that a portion of the human population could have some degree of resistance to H5N1 influenza, with the possibility that this could be induced or enhanced through immunization with seasonal influenza vaccines.
Journal Article
Maternal viral load monitoring: Coverage and clinical action at 4 Kenyan hospitals
by
Goggin, Kathy
,
Sandbulte, Matthew
,
Muchoki, Elizabeth
in
Antiretroviral drugs
,
Biology and Life Sciences
,
Breast feeding
2020
Kenya's guidelines for prevention of mother-to-child transmission of HIV (PMTCT) recommend routine viral load (VL) monitoring for pregnant and breastfeeding women.
We assessed PMTCT VL monitoring and clinical action occurring between last menstrual period (LMP) and 6 months postpartum at 4 Kenyan government hospitals. Pregnant women enrolled in the HIV Infant Tracking System from May 2016-March 2018 were included. We computed proportions who received VL testing within recommended timeframes and who received clinical action after unsuppressed VL result.
Of 424 participants, any VL testing was documented for 305 (72%) women and repeat VL testing was documented for 79 (19%). Only 115 women (27%) received a guideline-adherent baseline VL test and 27 (6%) received a guideline-adherent baseline and repeat VL test sequence. Return of baseline and repeat VL test results to the facility was high (average 96%), but patient notification of VL results was low (36% baseline and 49% repeat). Clinical action for unsuppressed VL results was even lower: 11 of 38 (29%) unsuppressed baseline results and 2 of 14 (14%) unsuppressed repeat results triggered clinical action.
Guideline-adherent VL testing and clinical intervention during PMTCT must be prioritized to improve maternal care and reduce the risk of HIV transmission to infants.
Journal Article
The type of adjuvant in whole inactivated influenza a virus vaccines impacts vaccine-associated enhanced respiratory disease
by
Souza, Carine K.
,
Gauger, Phillip C.
,
Loving, Crystal L.
in
Adjuvant
,
Adjuvants
,
Animal populations
2018
•The type of adjuvant in influenza vaccines impacted lung immunopathology with mismatched challenge virus.•Oil-in-water adjuvants induced potent homologous immune responses, but were associated with VAERD.•Adjuvanted WIV vaccines did not provide complete protection from heterologous challenge.
Influenza A virus (IAV) causes a disease burden in the swine industry in the US and is a challenge to prevent due to substantial genetic and antigenic diversity of IAV that circulate in pig populations. Whole inactivated virus (WIV) vaccines formulated with oil-in-water (OW) adjuvant are commonly used in swine. However, WIV-OW are associated with vaccine-associated enhanced respiratory disease (VAERD) when the hemagglutinin and neuraminidase of the vaccine strain are mismatched with the challenge virus. Here, we assessed if different types of adjuvant in WIV vaccine formulations impacted VAERD outcome. WIV vaccines with a swine δ1-H1N2 were formulated with different commercial adjuvants: OW1, OW2, nano-emulsion squalene-based (NE) and gel polymer (GP). Pigs were vaccinated twice by the intramuscular route, 3 weeks apart, then challenged with an H1N1pdm09 three weeks post-boost and necropsied at 5 days post infection. All WIV vaccines elicited antibodies detected using the hemagglutination inhibition (HI) assay against the homologous vaccine virus, but not against the heterologous challenge virus; in contrast, all vaccinated groups had cross-reactive IgG antibody and IFN-γ responses against H1N1pdm09, with a higher magnitude observed in OW groups. Both OW groups demonstrated robust homologous HI titers and cross-reactivity against heterologous H1 viruses in the same genetic lineage. However, both OW groups had severe immunopathology consistent with VAERD after challenge when compared to NE, GP, and non-vaccinated challenge controls. None of the WIV formulations protected pigs from heterologous virus replication in the lungs or nasal cavity. Thus, although the type of adjuvant in the WIV formulation played a significant role in the magnitude of immune response to homologous and antigenically similar H1, none tested here increased the breadth of protection against the antigenically-distinct challenge virus, and some impacted immunopathology after challenge.
Journal Article
Neuraminidase inhibiting antibody responses in pigs differ between influenza A virus N2 lineages and by vaccine type
by
Gauger, Phillip C.
,
Chen, Hongjun
,
Roth, James A.
in
Allergy and Immunology
,
Animal diseases
,
Animal populations
2016
•The NI responses in pigs vaccinated with LAIV, WIV or WT IAV were measured.•Vaccines induced strong NI responses, but was diminished in the presence of maternal antibodies.•Live viruses administered intranasally also induced NA responses in the respiratory tract.•Viruses containing N2 genes of different genotypes had minimal NA antibody cross-reactivity.•NA components of vaccines for swine must be updated along with the HA.
The neuraminidase (NA) protein of influenza A viruses (IAV) has important functional roles in the viral replication cycle. Antibodies specific to NA can reduce viral replication and limit disease severity, but are not routinely measured. We analyzed NA inhibiting (NI) antibody titers in serum and respiratory specimens of pigs vaccinated with intramuscular whole-inactivated virus (WIV), intranasal live-attenuated influenza virus (LAIV), and intranasal wild type (WT) IAV. NI titers were also analyzed in sera from an investigation of piglet vaccination in the presence of passive maternally-derived antibodies. Test antigens contained genetically divergent swine-lineage NA genes homologous or heterologous to the vaccines with mismatched hemagglutinin genes (HA). Naïve piglets responded to WIV and LAIV vaccines and WT infection with strong homologous serum NI titers. Cross-reactivity to heterologous NAs depended on the degree of genetic divergence between the NA genes. Bronchoalveolar lavage specimens of LAIV and WT-immunized groups also had significant NI titers against the homologous antigen whereas the WIV group did not. Piglets of vaccinated sows received high levels of passive NI antibody, but their NI responses to homologous LAIV vaccination were impeded. These data demonstrate the utility of the enzyme-linked lectin assay for efficient NI antibody titration of serum as well as respiratory tract secretions. Swine IAV vaccines that induce robust NI responses are likely to provide broader protection against the diverse and rapidly evolving IAV strains that circulate in pig populations. Mucosal antibodies to NA may be one of the protective immune mechanisms induced by LAIV vaccines.
Journal Article
Vaccination with NS1-truncated H3N2 swine influenza virus primes T cells and confers cross-protection against an H1N1 heterosubtypic challenge in pigs
by
Henningson, Jamie N.
,
Loving, Crystal L.
,
Lorusso, Alessio
in
Allergy and Immunology
,
Animals
,
Animals, Newborn
2012
► Attenuated H3N2 influenza vaccine with truncated NS1 was administered to pigs. ► Vaccine induced broadly reactive mucosal antibodies. ► Vaccine primed T cells which were elevated in peripheral blood after infection. ► Vaccinated animals had reduced shedding of heterosubtypic H1N1 challenge virus.
The diversity of contemporary swine influenza virus (SIV) strains impedes effective immunization of swine herds. Mucosally delivered, attenuated virus vaccines are one approach with potential to provide broad cross-protection. Reverse genetics-derived H3N2 SIV virus with truncated NS1 (NS1Δ126 TX98) is attenuated and immunogenic when delivered intranasally in young pigs. We analyzed T-cell priming and cross-protective efficacy in weanling piglets after intranasal inoculation with NS1Δ126 TX98 versus wild type TX98.
In vivo replication of the truncation mutant was minimal compared to the wild type virus. T-cell responses were greater in magnitude in pigs infected with the wild type virus in
in vitro restimulation assays. According to the expression of activation marker CD25, peripheral T cell recall responses in NS1Δ126 TX98 infected pigs were minimal. However, intracellular IFN-γ data indicate that the attenuated virus induced virus-specific CD4
+CD8
–, CD4
+CD8
+, CD4
–CD8
+, and γδ T cells within 28
days. The IFN-γ response appeared to contract, as responses were reduced at later time points prior to challenge. CD4
+CD8
+ cells isolated 5
days after heterosubtypic H1N1 challenge (day 70 overall) showed an elevated CD25 response to virus restimulation. Pigs previously infected with wild type TX98 were protected from replication of the H1N1 challenge virus. Vaccination with NS1Δ126 TX98 was associated with significantly lower levels of Th1-associated cytokines in infected lungs but provided partial cross-protection against the H1N1 challenge. These results demonstrate that NS1Δ SIV vaccines can elicit cell-mediated cross-protection against antigenically divergent strains.
Journal Article
Inactivated Seasonal Influenza Vaccines Increase Serum Antibodies to the Neuraminidase of Pandemic Influenza A(H1N1) 2009 Virus in an Age-Dependent Manner
2010
Levels of preexisting antibodies to the hemagglutinin of pandemic influenza A(H1N1) 2009 (hereafter pandemic H1N1) virus positively correlate with age. The impact of contemporary seasonal influenza vaccines on establishing immunity to other pandemic H1N1 proteins is unknown. We measured serum antibodies to the neuraminidase (NA) of pandemic H1N1 in adults prior to and after vaccination with seasonal trivalent inactivated influenza vaccines. Serum antibodies to pandemic H1N1 NA were observed in all age groups; however, vaccination elevated levels of pandemic H1N1 NA antibodies predominately in elderly individuals (age,⩾60 years). Therefore, contemporary seasonal vaccines likely contribute to reduction of pandemic H1N1-associated disease in older individuals.
Journal Article