Cacalia hastata L.: anti-influenza activity and phytochemical characteristics of extracts

This is the first study to assess antiviral activity against human influenza virus A/Aichi/2/68 and bird influenza virus A/chicken/Kurgan/05/2005 and phytochemical characteristics of an ethanol extract of Cacalia hastata L. from wild populations growing in the vicinity of Tomsk, Russia (mixed forest). A log10 neutralization index—an indicator of inhibition of virus replication by the extract from C. hastata leaves—was ≤2 lg for each influenza virus. The extract reduced the infectivity of the human influenza virus by 1.5-fold and that of the avian influenza virus by 1.7-fold. The phytochemical characterization of C. hastata (its various organs) showed that the largest amount of the tested biologically active substances is present in leaves and rhizomes.

Distinct Inductions of and Responses to Type I and Type III Interferons Promote Infections in Two SARS-CoV-2 Isolates

The recent emerging coronavirus, SARS-CoV-2, has been rapidly and widely spread and causing an ongoing viral pneumonia outbreak worldwide. It has been observed that SARS-CoV-2 patients show a rather long and asymptomatic incubation time. We characterized the abilities to induce and to response to IFNβ/IFNλ1 of two or our clinical isolates, SARS-CoV-2/NTU01/TWN/human/2020 and SARS-CoV-2/NTU02/TWN/human/2020, which exhibit only two amino acid differences over the ∼30kb viral genome. We found that both isolates may infect Huh7, A549 and Calu-3 cells, yet the RIG-I-like receptor-dependent antiviral signaling was poorly induced in these cells in the early infections. Unexpectedly, we found that the intracellular vRNA levels of these isolates were sustained upon to type I/III IFN treatments, and this phenotype was more pronounced in the Taiwan/NTU01/2020 isolate. The type I/III IFN responses are antiviral but partially proviral in the case of SARS-CoV-2 infections. Poor induction and response to innate immunity may contribute to destitute neutralization index of the antibody produced, and indeed we found that the patient serum could not efficiently neutralize SARS-CoV-2 virions. With better understandings of the interplay between SARS-CoV-2 and the host antiviral innate immunity, our report may provide new insights for the regimen of therapies for SARS-CoV-2 infected patients.

The Condition of Post-Vaccination Immunity to the Tick-Borne Encephalitis Virus in the Population Highly Endemic Area with Siberian Subtype Domination

Relevance.Modern inactivated culture vaccines against tick-borne encephalitis (TBE) with at least 70% of the population living in the natural foci of the FE give a high epidemiological effect. Unresolved issues are the simplification of the cumbersome vaccination scheme, the optimal number of revaccinations, the protective titer of antibodies against the Siberian subtype of the TBE virus dominant in Russia.Goalof this work is to study the state of postvaccinal immunity in the population of the highly endemic area of the Trans-Urals.Materials and methods. 1381 blood serum of the population vaccinated from 3 to 13 times with vaccines was studied: unconcentrated culture inactivated from strain No. 205 of the TBE virus produced by «Virion», Tomsk, «EnceVir» produced by «Microgen», Tomsk, produced by Chumakov Federal Scientific Center for Research and Development of Immuneand-Biological Products of Russian.To identify specific antibodies – IgG, IgM, antigen of TBE virus, sets of reagents of ELISA from «Vector-Best» were used. Neutralizing activity of sera was determined by the index of neutralization index with 4 strains of the Siberian subtype of TBE virus.Results.The immune layer among the vaccinated population in 10 districts of the Kurgan region, which differ in epidemiological tension, ranges from 69.9% to 94.6%. The intensity of humoral immunity varied according to IgG titers in ELISA from 1: 100 – 1: 200 to 1: 3200 (rarely 1: 6400). The duration and intensity of immunity depends on the number of vaccinations and the number of missed remote revaccinations. Preservation and intensity of immunity with reliability P = 95%, higher in persons vaccinated 6–10 times compared with the group of vaccinated 3 times. In persons who had 4–8 booster dose of vaccine, the immunity persisted for 15–19–36 years with an IgG titer of not more than 1: 100. The neutralizing activity of the sera of vaccinated individuals with antibody titers from 1:100 to 1: 6400 was studied for the Siberian subtype of BCE. The degree of protection of the vaccinated population against the doses of the virus found in individual mites is determined. From the doses of the virus, 57% of the vaccinated population are most often found in mites, and from the dose of 105– 8%. Recommendations are proposed on the tactics of revaccination of the population, depending on the level of immunity.

Evaluation of antibody response to Goat Pox cell culture vaccine in goats in India

Goat Pox is an important contagious viral disease that causes serious economic loss in small ruminants. The disease causes high morbidity, mortality and trade restriction. Several outbreaks of the disease are reported in Africa and Europe. In India also, the disease has high economic significance. Present study was undertaken to estimate specific antibody response to Live Goat Pox Vaccine in goats. Thirty-five healthy goats were vaccinated with single dose and 10 goats were kept as control. Blood was collected at defined intervals and sera were separated. Virus neutralization test was performed to estimate neutralization index as marker of antibody levels in serum. The study revealed that vaccine could induce immunity against the disease within seven days of vaccination, and reached a peak at 21 days. The titre remained at protective level throughout the oneyear study. Further study can be done to estimate the total duration of immunity through extended study, and the response to challenge with virus.Bangl. vet. 2016. Vol. 33, No. 1, 23-27

Virological and serological studies of Venezuelan equine encephalomyelitis in humans

During the 1971 epidemic of Venezuelan equine encephalomyelitis (VEE) in south Texas, 203 suspect VEE cases were evaluated by the Center for Disease Control. Sixty-seven were confirmed as cases of VEE. Laboratory confirmation was accomplished by isolation of VEE virus from a serum specimen taken during the acute illness in 50 (75%) of the confirmed cases. Serological confirmation was obtained in 17 cases (25%). Virus isolations were most often obtained from sera collected during the first 3 days of illness. Peak serum virus titers (algebraic mean, 10(5-7) suckling mouse intracranial 50% lethal doses [SMICLD50] per ml) occurred on day 2 of illness. One-half of the sera from which virus was isolated contained at least 10(5) SMICLD50/ml, which has been shown to be sufficient to infect some vector mosquitoes. Blood from 13 virus-positive VEE cases was obtained 1 and 11 months after illness. Hemagglutination-inhibiting, complement-fixing, and neutralizing antibodies were formed by all 13 patients 1 month after illness. Hemagglutination-inhibiting antibody titers were essentially unchanged 11 months after illness. Complement-fixing antibody was undetectable 11 months after illness in 23% of cases and was detectable at dilutions of 1:8 or 1:6 in 77%. Neutralizing antibody (measured by log neutralization index) was not detectable 1 year after illness in one person (8%); titers had declined from 1.0 to 2.0 in 46%, were unchanged in 39%, and were not tested in one person (8%). No evidence of intrafamilial spread of VEE virus was obtained in either of two illness and antibody surveys. A randomized household illness and antibody survey of 681 Port Isabel residents revealed an inapparent infection ratio of 1:11 and an overall antibody prevalence of 3.2%.

Infectious Pancreatic Necrosis: Clinical and Immune Response of Adult Trouts to Inoculation with Live Virus

Mature feral rainbow trout were inoculated with infectious pancreatic necrosis (IPN) virus and held at 12.5 C for 3 months to produce antibody and to determine whether or not disease would occur. Disease was not observed, but IPN virus-neutralizing antibody was found in pre-inoculation serum indicating the likelihood of prior infection. As measured by Neutralization Index, the immune response varied from weak to very strong. Neutralizing antibody was not found in sera from mature specific pathogen-free rainbow and brook trout. Although IPN virus also failed to produce clinical disease in adult brook trout it did establish a transient asymptomatic infection, and this resulted in high levels of neutralizing antibody.

HERPES SIMPLEX OF THE NEWBORN INFANT

A case of herpes simplex infection in the newborn infant is reported. No neutralizing antibody was found in the patient's serum at 10 or 24 days, but a neutralization index greater than 64,500 was found at 116 days.