Intranasal H5N1 vaccines, adjuvanted with chitosan derivatives, protect ferrets against highly pathogenic influenza intranasal and intratracheal challenge

We investigated the protective efficacy of two intranasal chitosan (CSN and TM-CSN) adjuvanted H5N1 Influenza vaccines against highly pathogenic avian Influenza (HPAI) intratracheal and intranasal challenge in a ferret model. Six groups of 6 ferrets were intranasally vaccinated twice, 21 days apart, with either placebo, antigen alone, CSN adjuvanted antigen, or TM-CSN adjuvanted antigen. Homologous and intra-subtypic antibody cross-reacting responses were assessed. Ferrets were inoculated intratracheally (all treatments) or intranasally (CSN adjuvanted and placebo treatments only) with clade 1 HPAI A/Vietnam/1194/2004 (H5N1) virus 28 days after the second vaccination and subsequently monitored for morbidity and mortality outcomes. Clinical signs were assessed and nasal as well as throat swabs were taken daily for virology. Samples of lung tissue, nasal turbinates, brain, and olfactory bulb were analysed for the presence of virus and examined for histolopathological findings. In contrast to animals vaccinated with antigen alone, the CSN and TM-CSN adjuvanted vaccines induced high levels of antibodies, protected ferrets from death, reduced viral replication and abrogated disease after intratracheal challenge, and in the case of CSN after intranasal challenge. In particular, the TM-CSN adjuvanted vaccine was highly effective at eliciting protective immunity from intratrache

Tetanus epidemiology in Europe and in Italy: a review.

A seroepidemiological study was performed on a sample of 522 subjects belonging to the open population of Southern Tuscany using an ELISA test

Studio sulle conoscenze del rischio di epatite B da parte del personale sanitario.

Atti 38° Congresso Nazionali Siti: Qualità in Sanità Pubblica: una strategia per l'Europa. Fiuggi, 27-30 settembre 1998

Intranasal H5N1 vaccines, adjuvanted with chitosan derivatives, protect ferrets against highly pathogenic influenza intranasal and intratracheal challenge

We investigated the protective efficacy of two intranasal chitosan (CSN and TM-CSN) adjuvanted H5N1 Influenza vaccines against highly pathogenic avian Influenza (HPAI) intratracheal and intranasal challenge in a ferret model. Six groups of 6 ferrets were intranasally vaccinated twice, 21 days apart, with either placebo, antigen alone, CSN adjuvanted antigen, or TM-CSN adjuvanted antigen. Homologous and intra-subtypic antibody cross-reacting responses were assessed. Ferrets were inoculated intratracheally (all treatments) or intranasally (CSN adjuvanted and placebo treatments only) with clade 1 HPAI A/Vietnam/1194/2004 (H5N1) virus 28 days after the second vaccination and subsequently monitored for morbidity and mortality outcomes. Clinical signs were assessed and nasal as well as throat swabs were taken daily for virology. Samples of lung tissue, nasal turbinates, brain, and olfactory bulb were analysed for the presence of virus and examined for histolopathological findings. In contrast to animals vaccinated with antigen alone, the CSN and TM-CSN adjuvanted vaccines induced high levels of antibodies, protected ferrets from death, reduced viral replication and abrogated disease after intratracheal challenge, and in the case of CSN after intranasal challenge. In particular, the TM-CSN adjuvanted vaccine was highly effective at eliciting protective immunity from intratracheal challenge; serologically, protective titres were demonstrable after one vaccination. The 2-dose schedule with TM-CSN vaccine also induced cross-reactive antibodies to clade 2.1 and 2.2 H5N1 viruses. Furthermore ferrets immunised with TM-CSN had no detectable virus in the respiratory tract or brain, whereas there were signs of virus in the throat and lungs, albeit at significantly reduced levels, in CSN vaccinated animals. This study demonstrated for the first time that CSN and in particular TM-CSN adjuvanted intranasal vaccines have the potential to protect against significant mortality and morbidity arising from infection with HPAI H5N1 virus

Serological Evidence for Circulation of Influenza D Virus in the Ovine Population in Italy

Influenza D virus (IDV) is a novel orthomyxovirus initially isolated from pigs exhibiting influenza-like disease in the USA. Since then, IDV has been detected worldwide in several host species, including livestock animals, whilst specific antibodies have been identified in humans, raising concerns about interspecies transmission and zoonotic risks. Few data regarding the seroprevalence of IDV in small ruminants have been available to date. In this study, we assessed the prevalence of antibodies against IDV in ovine serum samples in Sicily, Southern Italy. Six hundred serum samples, collected from dairy sheep herds located in Sicily in 2022, were tested by haemagglutination inhibition (HI) and virus neutralization (VN) assays using reference strains, D/660 and D/OK, representative of two distinct IDV lineages circulating in Italy. Out of 600 tested samples, 168 (28.0%) tested positive to either IDV strain D/660 or D/OK or to both by HI whilst 378 (63.0%) tested positive to either IDV strain D/660 or D/OK or to both by VN. Overall, our findings demonstrate that IDV circulates in ovine dairy herds in Sicily. Since IDV seems to have a broad host range and it has zoonotic potential, it is important to collect epidemiological information on susceptible species

SARS-CoV-2 escape from a highly neutralizing COVID-19 convalescent plasma

To investigate the evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the immune population, we coincupi bated the authentic virus with a highly neutralizing plasma from a COVID-19 convalescent patient. The plasma fully neutralized the virus for seven passages, but, after 45 d, the deletion of F140 in the spike N-terminal domain (NTD) N3 loop led to partial breakthrough. At day 73, an E484K substitution in the receptor-binding domain (RBD) occurred, followed, at day 80, by an insertion in the NTD N5 loop containing a new glycan sequon, which generated a variant completely resistant to plasma neutralization. Computational modeling predicts that the deletion and insertion in loops N3 and N5 prevent binding of neutralizing antibodies. The recent emergence in the United Kingdom, South Africa, Brazil, and Japan of natural variants with similar changes suggests that SARS-CoV-2 has the potential to escape an effective immune response and that vaccines and antibodies able to control emerging variants should be developed

Antibody responses of immunised ferrets to A/Vietnam/1194/2004 (clade 1), A/Indonesia/05/2005 (clade 2.1), & A/Turkey/Turkey/1/2005 (clade 2.2) H5N1 viruses by HAI (turkey and horse erythrocytes), VN, and SRH assays.

<p>All animals were intranasally immunised on days 0 and 21. Data presented for each of the vaccine groups before and after 1 vaccination (Day 0 and Day 21), 2 vaccinations (Day 42), and just prior to challenge (Day 48). Treatment groups were Placebo (PBS) n = 12; unadjuvanted/antigen alone (0.075 mg/mL HA) n = 6; CSN adjuvanted vaccine (0.075 mg/mL HA+5 mg/mL CSN) n = 12; & TM-CSN adjuvanted vaccine (0.075 mg/mL HA+5 mg/mL CSN) n = 6. Bars represent geometric mean group values (horizontal bars) and ±SD (vertical bars). Vaccine responses are as follows: graphs A, D, G, & J are responses to A/Vietnam/1194/2004, as measured by HAI (turkey erythrocytes), HAI (horse erythrocytes), VN & SRH respectively; B, E, H, & K are responses to A/Indonesia/05/2005; C, F, I, & L are responses to A/Turkey/Turkey/1/2005. Seroconverting ferrets (threshold represented by blue horizontal dotted line) were defined as those animals with an equal or greater than 4 fold increase in titre from baseline for the HAI and VN assays. Those that attain an area of 25 mm² or more for the SRH assay were defined as seroprotected. Seroprotection levels for the HAI assay were defined as equal or greater than 40HAI (threshold represented by red horizontal dotted line).</p

Histopathology in control and vaccinated ferrets post challenge.

<p>Histopathology was performed on ferrets that were euthanised according to schedule as well as animals euthanized prematurely on welfare groups and any decedents. In those ferrets that were not euthanised according to the schedule all had acute severe pneumonia or diffuse alveolar damage, which was attributed to the likely cause of death. None of those animals that were affected by encephalitis had to be euthanised prematurely. Each panel represents: (A) extent of alveolitis, (B) severity of alveolitis, (C) relative weight of lung, (D) percentage lung affected, and (E) severity of rhinitis.</p

Summary of ferret treatment groups and vaccine and adjuvant formulations tested.

<p>Summary of ferret treatment groups and vaccine and adjuvant formulations tested.</p