Principal Component Analysis of Mobility Data from an Operational GPRS Network

We present a preliminary analysis of mobility data collected from an operational GPRS network. The input data are time-series counting the number of mobile stations present in each of 126 sample routing areas at equally spaced instants (5 min) during one full week. The time-series were extracted from packet-level traces captured by passively monitoring a subset of the Gb links of the network of Mobilkom Austria AG & Co KG during October 2004. We apply the principal component analysis (PCA) to this dataset. The PCA offers a simple method for classifying the routing areas into two main groups, residential and business areas, plus a few "atypical" ones. Additionally, we address the problem of robustness of the PCA to temporary local gaps in the input data

Full inactivation of human influenza virus by high hydrostatic pressure preserves virus structure and membrane fusion while conferring protection to mice against infection.

Whole inactivated vaccines (WIVs) possess greater immunogenicity than split or subunit vaccines, and recent studies have demonstrated that WIVs with preserved fusogenic activity are more protective than non-fusogenic WIVs. In this work, we describe the inactivation of human influenza virus X-31 by high hydrostatic pressure (HHP) and analyze the effects on the structure by spectroscopic measurements, light scattering, and electron microscopy. We also investigated the effects of HHP on the glycoprotein activity and fusogenic activity of the viral particles. The electron microscopy data showed pore formation on the viral envelope, but the general morphology was preserved, and small variations were seen in the particle structure. The activity of hemagglutinin (HA) during the process of binding and fusion was affected in a time-dependent manner, but neuraminidase (NA) activity was not affected. Infectious activity ceased after 3 hours of pressurization, and mice were protected from infection after being vaccinated. Our results revealed full viral inactivation with overall preservation of viral structure and maintenance of fusogenic activity, thereby conferring protection against infection. A strong response consisting of serum immunoglobulin IgG1, IgG2a, and serum and mucosal IgA was also detected after vaccination. Thus, our data strongly suggest that applying hydrostatic pressure may be an effective method for developing new vaccines against influenza A as well as other viruses

Viral proteins structure is slightly affected by HHP treatment.

<p>(A) The changes in spectral center of mass (●) and light scattering (○) were followed as a function of the pressure at 289.6 MPa over 6 h. For tryptophan fluorescence emission, the sample was excited at 280 nm, and the emission was measured at 300 to 420 nm. (B) The influenza virus was pre-incubated for 10 min with 15 mM of bis-ANS probe and then exposed to 289.6 MPa for 3 h, and the intensity of the probe was measured every 10 min.</p

HHP treatment preserves viral fusogenic activity.

<p>Virus samples were pressurized for 3, 6, or 12 h at 289.6 MPa. (A) Viruses were incubated with DiD and monitored for their fusogenic properties. Mock (cells incubated with PBS), control (influenza viruses kept for 12 h at 25°C), and pressurized influenza virus. (B) Fusogenic activity relative to the control. The asterisks (***) mark a significant difference (***p<0.0001 by Tukey´s post-test).</p

Viral glycoproteins remain functional after pressurization.

<p>(A) Hemagglutination assay titer of viruses pressurized at pH 7.4 for 3, 6, or 12 h at 289.6 MPa. Hemagglutination units were given by the reciprocal of the highest dilution where total hemagglutination was observed. (B) X-31 NA activity. Virus particles were pressurized at pH 7.4 for 3 h at 289.6 MPa. Enzymatic activity was determined with the MUNANA substrate, as described in the Materials and Methods. The NA activity was calculated by normalizing the NA activity of the pressurized virus to the NA activity of the native virus. </p

Intradermal Immunization of SARS-CoV-2 Original Strain Trimeric Spike Protein Associated to CpG and AddaS03 Adjuvants, but Not MPL, Provide Strong Humoral and Cellular Response in Mice

Despite the intramuscular route being the most used vaccination strategy against SARS-CoV-2, the intradermal route has been studied around the globe as a strong candidate for immunization against SARS-CoV-2. Adjuvants have shown to be essential vaccine components that are capable of driving robust immune responses and increasing the vaccination efficacy. In this work, our group aimed to develop a vaccination strategy for SARS-CoV-2 using a trimeric spike protein, by testing the best route with formulations containing the adjuvants AddaS03, CpG, MPL, Alum, or a combination of two of them. Our results showed that formulations that were made with AddaS03 or CpG alone or AddaS03 combined with CpG were able to induce high levels of IgG, IgG1, and IgG2a; high titers of neutralizing antibodies against SARS-CoV-2 original strain; and also induced high hypersensitivity during the challenge with Spike protein and a high level of IFN-&gamma; producing CD4+ T-cells in mice. Altogether, those data indicate that AddaS03, CpG, or both combined may be used as adjuvants in vaccines for COVID-19