Active immunization in the United States: developments over the past decade

Case report of congenital asplenia presenting with Haemophilus influenzae type a (Hia) sepsis: an emerging pediatric infection in Minnesota

Background

In the pre-vaccine era, invasive disease with Haemophilus influenzae, type b (Hib) commonly presented with osteoarticular involvement. Haemophilus influenzae, type a (Hia) sepsis is a rare but emerging problem in recent years. Here, we report a case of sepsis with concomitant osteoarthritis due to Hia that was the presenting infectious disease manifestation of isolated asplenia in a young child. This unique observation adds to our understanding of sepsis and asplenia in children.

Case presentation

A five-year-old girl developed acute Hia bacteremia and sepsis. The patient developed arthritis shortly after onset of septic shock. Arthrocentesis was culture-negative, but given the difficulty differentiating between septic and reactive arthritis, prolonged antibiotic administration was provided for presumed osteoarticular infection, and the patient had an uneventful recovery. The finding of Howell-Jolly bodies on blood smear at the time of presentation prompted an evaluation that revealed isolated congenital asplenia. Evaluation for known genetic causes of asplenia was unrevealing. Investigation by the Minnesota Department of Health revealed an emergence of Hia infections over the past 5 years, particularly in children with an American Indian background.

Conclusions

Hia is an important pathogen in the differential diagnosis of invasive bacterial infections in children and shares overlap in clinical presentation and pathogenesis with Hib. Invasive Hia disease can be a presenting manifestation of asplenia in children. Hia is an emerging pathogen in American Indian children.

Evaluation of impact of one dose varicella vaccine on the incidence of chickenpox in Argentina

INTRODUCTION

Varicella, also known as chickenpox is one of the most common immunizable diseases. In 1998, the World Health Organization (WHO) recommended to incorporate this vaccine in the national immunization programs, which Argentina did in 2015.

OBJECTIVES

To describe the behavior of the varicella time series for the 2005-2017 period, and to evaluate the impact of the vaccine in Argentina.

METHODOLOGY

An ecological observational study was performed, using the varicella cases reported in the National Health Monitoring System, and the data of the National census as secondary data sources. A model based time series analysis of the notified varicella cases in Argentina was performed, using a Negative Binomial Mixed Model. For the verification of the vaccine impact, the 2005-2014 period was selected, and a prognosis for the following years was performed. Impact was evaluated by comparing the rates and confidence intervals between the predicted and observed values.

RESULTS

Argentina reported 1,775,587 varicella cases for the 2005-2017 period. The series exhibited seasonality, and, a decreasing trend in the number of cases was observed in 2016 and 2017. A reduction of the incidence rate after the implementation of the vaccine was observed. The transmission risk decreased in the country after vaccine implementation.

CONCLUSIONS

This study is the first concrete evidence of the varicella incidence decline after the implementation of a single dose application program in Argentina.

Acute pulmonary complications of sickle cell disease

Acute pulmonary problems in sickle cell disease (SCD) patients, in particular acute chest syndrome (ACS), cause significant mortality and morbidity. It is important to differentiate ACS from pneumonia to avoid inappropriate or inadequate treatment. Asthma may increase the risk of ACS and co-morbid asthma and SCD are associated with worse patient outcomes and, in preclinical models, more severe inflammation. Recurrent wheezing, however, can occur in the absence of a diagnosis of asthma; it is likely due to SCD related inflammation and additional therapies than those that treat asthma may be required. Further research is merited to clarify these issues.

Production of inflammatory cytokines in response to diphtheria-pertussis-tetanus (DPT), haemophilus influenzae type b (Hib), and 7-valent pneumococcal (PCV7) vaccines

Haemophilus influenzae type b (Hib) and 7-valent pneumococcal (PCV7) vaccines both became recommended in Japan in 2010. In this study, cytokine production was investigated in peripheral blood mononuclear cells (PBMCs) cultures stimulated with diphtheria and tetanus toxoids combined with acellular pertussis vaccine (DPT), Hib, and PCV7 separately or concurrent different combinations, all as final off-the-shelf vaccines without the individual vaccine components as controls. Higher IL-1β levels were produced when cultures were stimulated with PCV than with DPT or Hib, and the concurrent stimulation including PCV7 enhanced the production of IL-1β. Although Hib induced higher levels of IL-6, no significant difference was observed in IL-6 production with the concurrent stimulation. The concurrent stimulation with Hib/PCV7 and DPT/Hib/PCV7 produced higher levels of TNF-α and human G-CSF. Cytokine profiles were examined in serum samples obtained from 61 vaccine recipients with febrile reactions and 18 recipients without febrile illness within 24 h of vaccination. No significant difference was observed in cytokine levels of IL-1β, IL-4, IL-6, IL-10, IL-12, IFN-γ, MIP-1, TNF-α, and prostaglandin E2 (PGE2) in sera between the two groups. However, significantly higher levels of human G-CSF were observed in recipients with febrile illness than in those without febrile reactions. Further investigations of the significance of elevated serum G-CSF levels are required in vaccine recipients with febrile illness.

Vaccine chronicle in Japan

The concept of immunization was started in Japan in 1849 when Jenner's cowpox vaccine seed was introduced, and the current immunization law was stipulated in 1948. There have been two turning points for amendments to the immunization law: the compensation remedy for vaccine-associated adverse events in 1976, and the concept of private vaccination in 1994. In 1992, the regional Court of Tokyo, not the Supreme Court, decided the governmental responsibility on vaccine-associated adverse events, which caused the stagnation of vaccine development. In 2010, many universal vaccines became available as the recommended vaccines, but several vaccines, including mumps, zoster, hepatitis B, and rota vaccines, are still voluntary vaccines, not universal routine applications. In this report, immunization strategies and vaccine development are reviewed for each vaccine item and future vaccine concerns are discussed.

Of Mice and Men: On the Origin of XMRV

The novel human retrovirus xenotropic murine leukemia virus-related virus (XMRV) is arguably the most controversial virus of this moment. After its original discovery in prostate cancer tissue from North American patients, it was subsequently detected in individuals with chronic fatigue syndrome from the same continent. However, most other research groups, mainly from Europe, reported negative results. The positive results could possibly be attributed to contamination with mouse products in a number of cases, as XMRV is nearly identical in nucleotide sequence to endogenous retroviruses in the mouse genome. But the detection of integrated XMRV proviruses in prostate cancer tissue proves it to be a genuine virus that replicates in human cells, leaving the question: how did XMRV enter the human population? We will discuss two possible routes: either via direct virus transmission from mouse to human, as repeatedly seen for, e.g., Hantaviruses, or via the use of mouse-related products by humans, including vaccines. We hypothesize that mouse cells or human cell lines used for vaccine production could have been contaminated with a replicating variant of the XMRV precursors encoded by the mouse genome.

Isolation, identification, and characterization of small bioactive peptides from Lactobacillus GG conditional media that exert both anti-Gram-negative and Gram-positive bactericidal activity

OBJECTIVES

Diarrheal diseases remain a major human plague that still claim millions of lives every year. Probiotics, including Lactobacillus GG (LGG), are known to have a beneficial effect on diarrheal diseases, but their mechanism of action has not yet been completely established. Therefore, the main objective of this work was to identify and characterize moieties elaborated by LGG that exert antibacterial activity.

MATERIALS AND METHODS

Lactobacillus GG conditional media was subjected to liquid chromatography/mass spectrometry. The identified peptides were synthesized by Symphony peptide synthesizer and purified by HPLC using Dynamax reverse-phase C18 column. Using A600 measurement and tested for their antibacterial activity.

RESULTS

We identified 7 small peptides from LGG cultured media, 2 of which are NPSRQERR and PDENK, retained the antibacterial activity detected with LGG conditional media. The antibacterial activity was exerted against both Gram-negative (Escherichia coli EAEC 042 and Salmonella typhi) and, with less potency, Gram-positive (Staphylococcus aureus) bacteria.

CONCLUSIONS

Lactobacillus GG elaborates small peptides showing various degrees of antibacterial activity. NPSRQERR showed the most potent antibacterial effect that was detected both in Gram-negative and Gram-positive microorganisms. These synthetic peptides may represent novel tools for the treatment of bacterial infectious diseases.

Mechanisms of Inactivation of HSV-2 during Storage in Frozen and Lyophilized Forms

The structural integrity of herpes simplex virus 2 (HSV-2) during freezing, thawing, and lyophilization has been studied using scanning and transmission electron microscopy. Viral particles should be thawed quickly from -80 to 37 degrees C to avoid artifacts of thawing. To avoid freezing damage, the virus should be rapidly frozen (>20 K s(-1)) rather than slowly frozen as occurs on the shelf of a lyophilizer (<1 K s(-1)). Fast freezing and thawing allows six cycles of freeze thaw with no loss of viral titer TCID50. Viral particles were characterized using immunogold labeling methods. Freshly thawed virus had 19 +/- 4 polyclonal immunogold particles virus(-1); virus stored at -80 degrees C for at least 4 months had 17 +/- 3 particles virus(-1); virus stored for 1 week at 4 degrees C had 8 +/- 4 particles virus(-1). By bulk lyophilization the number of particles was 4 +/- 4, but by fast freezing and lyophilization the number of gold particles improved to 12 +/- 5. The loss of viral membrane was directly observed, and the in vitro loss was demonstrated to occur through three possible pathways, including (i) simultaneous release of tegument and membrane, (ii) sequential release of membrane and then tegument, and (iii) release like by in vivo infection. The capsids were not further degraded as indicated by the lack of free DNA, which was only released by boiling the viral samples with 1% SDS, followed by a dilution to 0.001% w/v SDS for the real-time PCR reaction.

The prospective preventative HIV vaccine based on modified poliovirus

In order to control HIV pandemic, many vaccines are invented. Although none first verified its efficacy in clinic, we hypothesize that HIV vaccine based on poliovirus is potential to develop the promising one, because it can elicit the broad immune response including the main mucosal, humoral and cellular reaction. However, the viral neural virulence is one major concern. The attenuated Sabin strain is a better candidate. While partial poliovirus genes are replaced by HIV antigen genes, the defective interfering particle will fail to produce progeny virions, which may further ensure its security. Although the vaccinal immune efficacy was verified in some similar animal experiments based on poliovirus to express the exogenous genes, more animal and clinical immune trials about HIV-poliovirus chimeric minireplicons are to be carried out and the hypotheses are to be validated.

Protective efficacy of a DNA influenza virus vaccine is markedly increased by the coadministration of a Schiff base-forming drug

Effective vaccination against heterologous influenza virus infection remains elusive. Immunization with plasmid DNA (pDNA) expressing conserved genes from influenza virus is a promising approach to achieve cross-variant protection. However, despite having been described for more than a decade, pDNA vaccination still requires further optimization to be applied clinically as a standard vaccination approach. We have recently described a simple and efficient approach to enhance pDNA immunization, based on the use of tucaresol, a Schiff base-forming drug. In this report we have tested the ability of this drug to increase the protection conferred by pDNA vaccination against influenza virus infection. Our results demonstrate that a significant protection was achieved in two strains of mice by using the combination of pDNA and tucaresol. This protection was associated with an elevated humoral and cellular response and a switch in the type of the T helper cell (Th) immune response from type 2 to type 1. This vaccine combination represents a promising strategy for designing a clinical study for the protection from influenza and similar infections.

Neurological adverse events associated with vaccination

Public tolerance to adverse reactions is minimal. Several reporting systems have been established to monitor adverse events following immunization. The present review summarizes data on neurologic complications following vaccination, and provides evidence that indicates whether they were directly associated with the vaccines. These complications include autism (measles vaccine), multiple sclerosis (hepatitis B vaccine), meningoencephalitis (Japanese encephalitis vaccine), Guillain-Barré syndrome and giant cell arteritis (influenza vaccine), and reactions after exposure to animal rabies vaccine. Seizures and hypotonic/hyporesponsive episodes following pertussis vaccination and potential risks associated with varicella vaccination, as well as vaccine-associated paralytic poliomyelitis following oral poliovirus vaccination, are also described. In addition, claims that complications are caused by adjuvants, preservatives and contaminants [i.e. macrophagic myofasciitis (aluminium), neurotoxicity (thimerosal), and new variant Creutzfeldt-Jakob disease (bovine-derived materials)] are discussed.