Publications by authors named "Zeijst B"

Not all physicians advocate for large-scale vaccination programmes against COVID-19. In this article, we respond on some of their reflections. Moreover, we explain that there are strong arguments for these large-scale vaccination programmes, aimed to prevent COVID-19 associated morbidity, mortality and overwhelmed health care systems, and to hinder the emergence of new strains of SARS-CoV-2 by reducing the virus transmission.

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Background: The Neural Cell Adhesion Molecule (NCAM) is a glycoprotein expressed as 120, 140 and/or 180 kDa isoforms, all derived through alternative splicing of a single gene. NCAM 120 contains no intracellular domain, whereas NCAM 140 and 180 have different intracellular domains determined by alternative splicing of exon 18. NCAM has been described as a biomarker to discriminate small cell lung cancer (SCLC) from non-SCLC (NSCLC).

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An improved whole cell pertussis vaccine, designated as Plow, which is low in endotoxicity due to a chemical extraction of lipo-oligosaccharide (LOS) from the outer membrane, was evaluated for safety, immunogenicity and potency, comparatively to a traditional whole cell pertussis vaccine. Current whole cell pertussis vaccines are effective but contain large quantities of endotoxin and consequently display local and systemic adverse reactions after administration. Endotoxin is highly inflammatory and contributes considerably to the reactogenicity as well as the potency of these vaccines.

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Seasonal influenza causes more morbidity and mortality in older adults than in young adults, apparently because of a decline in immune function with increasing age, known as immunosenescence. In this study, we compared the capacity of dendritic cells (DCs) from healthy older adults (≥65 years) with DCs from healthy young adults (20-40 years) to initiate a T cell response against influenza. DCs from older adults were impaired in the induction of influenza-specific CD8+ T cells as compared to DCs from young adults, which was demonstrated by a decreased proliferation, an impaired production of IFN-γ and a reduced expression of the degranulation marker CD107a by CD8+ T cells.

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Influenza infections are responsible for significant morbidity and mortality each year, with the highest infection rates found in the elderly population. The main strategy to reduce the impact of influenza infections in the elderly population is vaccination. However, the efficacy of influenza vaccines that are licensed for use in the elderly is relatively low (17-53%).

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Congenital cytomegalovirus (CMV) infection is an important public health problem with approximately 7 in 1,000 newborns infected and consequently at risk for hearing impairment. Newborn hearing screening will fail to detect this hearing impairment in approximately half of the cases because late onset hearing loss is frequent. Hearing impairment has profound impact on cognitive and social development of children and their families, determining most of the disease burden of congenital CMV infection.

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Hepatitis B is a serious public health problem. Worldwide three different levels of hepatitis B endemicity (high, intermediate and low) can be distinguished. Areas with different levels of endemicity require tailored vaccination strategies to fit the needs for individuals at risk and/or countries, depending on the infection risk per age group, vaccination rate, duration of protection after vaccination, cost effectiveness of vaccination strategies and ease of implementation in the national immunization schedules.

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Preparing populations for health threats, including threats from new or re-emerging infectious diseases is recognised as an important public health priority. The development, production and application of emergency vaccinations are the important measures against such threats. Vaccines are cost-effective tools to prevent disease, and emergency vaccines may be the only means to prevent a true disaster for global society in the event of a new pandemic with potential to cause morbidity and mortality comparable to the Spanish flu, the polio epidemics in the 1950s, or the SARS outbreak in 2003 if its spread had not been contained in time.

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The decision to include a vaccine in a national vaccination programme (or not) is usually evidence-based. Thereby, it is essential that the target disease causes a high burden of disease and that vaccination reduces this burden considerably. Furthermore, vaccination should be considered to be cost-effective by a government.

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There is concern that variola virus, the aetiological agent of smallpox, may be used as a biological weapon. For this reason several countries are now stockpiling (vaccinia virus-based) smallpox vaccine. Although the preventive use of smallpox vaccination has been well documented, little is known about its efficacy when used after exposure to the virus.

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The use of classical smallpox vaccines based on vaccinia virus (VV) is associated with severe complications in both naive and immune individuals. Modified vaccinia virus Ankara (MVA), a highly attenuated replication-deficient strain of VV, has been proven to be safe in humans and immunocompromised animals, and its efficacy against smallpox is currently being addressed. Here we directly compare the efficacies of MVA alone and in combination with classical VV-based vaccines in a cynomolgus macaque monkeypox model.

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In a search for the genetic basis for the structural difference between the related Streptococcus pneumoniae capsular serotypes 15B and 15C and for the reported reversible switching between these serotypes, the corresponding capsular polysaccharide synthesis (cps) loci were investigated by keeping in mind that at the structural level, the capsules differ only in O acetylation. The cps locus of a serotype 15B strain was identified, partially PCR amplified with primers based on the related serotype 14 sequence, and sequenced. Sequence analysis revealed, among other open reading frames, an intact open reading frame (designated cps15bM) whose product, at the protein level, exhibited characteristics of previously identified acetyltransferases.

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Screening of 7,680 Salmonella enterica serovar Enteritidis mutants for attenuation in a chicken macrophage infection model yielded a series of mutants including several with defects in previously unrecognized Salmonella virulence genes. One of the newly identified genes was the pbpA2 gene, belonging to the penicillin binding protein gene family.

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The capsular polysaccharide (CPS) synthesis locus of Streptococcus pneumoniae serotype 9V was amplified by long-range PCR and sequenced. The locus was 17368 bp in size and contained 15 ORFs. The genetic organization of the cluster shared many features with other S.

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Campylobacter jejuni is an enteropathogen for humans but commensal for chickens. In both hosts, the flagella and motility are important colonization factors. The flagellin gene is duplicated in Campylobacter, but only one flagellin gene, flaA, is sufficient for motility.

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The direct repeat region in Mycobacterium tuberculosis complex strains is composed of multiple direct variant repeats (DVRs), each of which is composed of a 36-bp direct repeat (DR) plus a nonrepetitive spacer sequence of similar size. It has been shown previously that clinical isolates show extensive polymorphism in the DR region by the variable presence of DVRs, and this polymorphism has been used in the epidemiology of tuberculosis. In an attempt to better understand the evolutionary scenario leading to polymorphic DR loci and to improve strain differentiation by spoligotyping, we characterized and compared the DNA sequences of the complete DR region and its flanking DNA of M.

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A nonflagellated mutant of Salmonella enterica serotype Enteritidis was constructed by disrupting the flagellin gene (fliC). Northern blot analysis indicated that the mutation did not affect expression of the downstream fliU gene. Infection experiments with differentiated Caco-2 cells revealed that the mutant was about 50-fold less invasive than the wild-type strain, while bacterial adherence was unaffected.

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Given the lack of functional transposons for use in Campylobacter spp., an alternative method of insertional mutagenesis using natural transformation was developed. High efficiencies of transformation were only obtained with species-specific DNA.

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The aim of the study was to monitor the course of digital dermatitis after local antibiotic treatment in an experimental group (treated on diagnosis) and a control group (treated 5 days later). The present study was carried out on 2 farms involving 18 animals. Monitoring was performed by means of clinical findings and detection of spirochetes on the surface of the lesions, using a polymerase chain reaction.

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Thirty-three family dogs were monitored for antibodies to Borrelia burgdorferi sensu lato over a 3-year period. Serum samples were collected before and during the season of high tick activity. Antibody levels were measured with an ELISA based on whole-cell antigens and an ELISA with a purified recombinant flagellin (r410).

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