From research to rapid response: mass COVID-19 testing by volunteers at the Centre for Genomic Regulation.

The COVID-19 pandemic has posed and is continuously posing enormous societal and health challenges worldwide. The research community has mobilized to develop novel projects to find a cure or a vaccine, as well as to contribute to mass testing, which has been a critical measure to contain the infection in several countries. Through this article, we share our experiences and learnings as a group of volunteers at the Centre for Genomic Regulation (CRG) in Barcelona, Spain. As members of the ORFEU project, an initiative by the Government of Catalonia to achieve mass testing of people at risk and contain the epidemic in Spain, we share our motivations, challenges and the key lessons learnt, which we feel will help better prepare the global society to address similar situations in the future.

Synergistic effect of high hydrostatic pressure (HHP) and marination treatment on the inactivation of hepatitis a virus in mussels (Mytilus galloprovincialis).

Consumption of raw or insufficiently cooked mussels contaminated with hepatitis A virus (HAV) is a major cause of infection to humans. The origin of mussels commonly used for the preparation of marinated seafood salads is often unknown, since different producers worldwide undergo a precooking treatment at the original collection site with methods and parameters not always indicated. These treatments could be insufficient for the inactivation of HAV, which is characterized by a high temperature resistance. Both high hydrostatic pressure (HHP) and marinade treatments have been shown to affect HAV vitality. In this study, two treatments (HHP and marinating) were combined in order to assess a potential synergistic effect on the virus vitality. A kinetic test was conducted by subjecting the experimentally-contaminated mussels (HAV titre: 10(6)/ml TCID50) to marinating, and to different HHP treatment (4,000; 5,000; and 6,000 bar for 1, 5, and 9 min). Virus post-treatment vitality was assessed by its ability to grow on cell cultures and by quantitative real-time RT-PCR to evaluate virus resistance under such conditions. Marinating treatment alone (final pH 4.3, and NaCl 2 %) did not inactivate the virus. On the other hand, the use of HHP treatment alone on non-marinated HAV-contaminated mussels was effective only above 5,000 bar for 5 min. The results of the present study elucidate the synergistic effect of a combination between marination and HHP treatments on the inactivation of the virus.

Infectivity of H7 LP and HP influenza viruses at different temperatures and pH and persistence of H7 HP virus in poultry meat at refrigeration temperature.

The aims of this study were to assess the infectivity of highly pathogenic (HP) and low pathogenicity (LP) H7 AI viruses at different temperatures and pH values and to investigate the persistance of HP H7 virus in chicken, turkey and duck meat. The H7 viruses tested remained infectious at +4°C and +20°C for 200 and >50 days, respectively. At pH 5, H7 viruses retained their infectivity for a shorter period of time compared to pH 7. The infectivity of HP H7 was detected >2 months in meat maintained at +4°C and was higher in chicken meat compared to turkey and duck meat. Results of this study show that higher temperatures and lower pH values both reduce virus infectivity and demonstrate that HP H7 virus can remain infectious in meat for extended periods of time.

A proof-of-principle study to identify suitable vaccine seed candidates to combat introductions of Eurasian lineage H5 and H7 subtype avian influenza viruses.

Vaccination against avian influenza (AI) is now included amongst the prevention and control measures recommended by international animal health organizations to combat the disease in poultry. For optimal control of human influenza infections, the antigenic variability within subtypes requires the annual update of seed strains for inclusion in vaccines. The decisions taken are based on serological cross-reactivity of viral strains measured by haemagglutination inhibition (HI) tests. The reason for this is to ensure that the vaccine contains strains that are related antigenically to the current circulating field strain as field viruses evolve or are substituted by variants of distinct antigenicity. Such an annual approach is not viable economically for the poultry industry. In the current study, we have applied a similar HI-based approach to demonstrate, as proof of principle, that cross-reactive strains can be identified. Applying the same approach used by the World Health Organization to investigate antigenic differences among human influenza viruses, we assessed the serological cross-reactivity of a selection of natural H5 and H7 subtype viruses. Analysing HI data, we have identified strains that are cross-reactive and may have the potential to act as seed viruses for future vaccine development. This study should be considered a starting point for a more informed approach to the selection of seed strains for the development of avian influenza vaccines against field infections caused by viruses of H5 and H7 subtypes.

The mouse model is suitable for the study of viral factors governing transmission and pathogenesis of highly pathogenic avian influenza (HPAI) viruses in mammals.

Highly pathogenic avian influenza (HPAI) viruses of the H5 and H7 subtype pose a major public health threat due to their capacity to cross the species barrier and infect mammals, for example dogs, cats and humans. In the present study we tested the capacity of selected H7 and H5 HPAI viruses to infect and to be transmitted from infected BALB/c mice to contact sentinels. Previous experiments have shown that viruses belonging to both H5 and H7 subtypes replicate in the respiratory tract and central nervous system of experimentally infected mice. In this study we show that selected H7N1 and H5N1 HPAI viruses can be transmitted from mouse-to-mouse by direct contact, and that in experimentally infected animals they exhibit a different pattern of replication and transmission. Our results can be considered as a starting point for transmission experiments involving other influenza A viruses with alpha 2-3 receptor affinity in order to better understand the viral factors influencing transmissibility of these viruses in selected mammalian species.

Evaluation of the protection induced by avian influenza vaccines containing a 1994 Mexican H5N2 LPAI seed strain against a 2008 Egyptian H5N1 HPAI virus belonging to clade 2.2.1 by means of serological and in vivo tests.

Since 2006 Egypt has been facing an extensive epidemic of H5N1 highly pathogenic avian influenza (HPAI) with a huge number of outbreaks both in rural and intensively reared poultry areas. The use of efficacious vaccines in this country has been, and still remains, essential for the control and possible eradication of HPAI. The present study was performed to establish whether the administration of inactivated vaccines containing an H5 virus belonging to a different lineage to the Eurasian H5N1 HPAI viruses guarantees protection from clinical signs, provides significant immune response and is able to achieve a reduction of viral shedding in the face of a challenge with a contemporary H5N1 virus isolated in Egypt. Despite the genetic and antigenic differences between the vaccine strain (H5N2/Mexico) and the challenge strain (H5N1/Egypt), confirmed by molecular and serological (haemagglutination inhibition) tests, it was established that the immune response induced by these conventional vaccines is sufficient to prevent infection in the majority of birds challenged with a contemporary H5N1 Egyptian strain. The data reported in this study also indicate that there may be a low degree of correlation between haemagglutination inhibition titres, clinical protection and reduction of shedding.

Unexpected heat resistance of Italian low-pathogenicity and high-pathogenicity avian influenza A viruses of H7 subtype to prolonged exposure at 37 degrees C.

The increased attention of the international community to the occurrence of repeated outbreaks of avian influenza infections worldwide has highlighted several knowledge gaps in the field. Among these, within the scope of the European Union-funded project Fluresist, we addressed the resistance of selected H7 subtype strains at 37 degrees C. In general terms, resistance was high, although some strains were more resistant than others, remaining viable after 15 days at 37 degrees C. These results should be considered when designing guidelines for outbreak management.

Conventional inactivated bivalent H5/H7 vaccine prevents viral localization in muscles of turkeys infected experimentally with low pathogenic avian influenza and highly pathogenic avian influenza H7N1 isolates.

Highly pathogenic avian influenza (HPAI) viruses cause viraemia and systemic infections with virus replication in internal organs and muscles; in contrast, low pathogenicity avian influenza (LPAI) viruses produce mild infections with low mortality rates and local virus replication. There is little available information on the ability of LPAI viruses to cause viraemia or on the presence of avian influenza viruses in general in the muscles of infected turkeys. The aim of the present study was to determine the ability of LPAI and HPAI H7N1 viruses to reach muscle tissues following experimental infection and to determine the efficacy of vaccination in preventing viraemia and meat localization. The potential of infective muscle tissue to act as a source of infection for susceptible turkeys by mimicking the practice of swill-feeding was also investigated. The HPAI virus was isolated from blood and muscle tissues of all unvaccinated turkeys; LPAI could be isolated only from blood of one bird and could be detected only by reverse transcriptase-polymerase chain reaction in muscles. In contrast, no viable virus or viral RNA could be detected in muscles of vaccinated/challenged turkeys, indicating that viral localization in muscle tissue is prevented in vaccinated birds.

Characterization of Newcastle disease virus isolates obtained from Eurasian collared doves (Streptopelia decaocto) in Italy.

Eurasian collared doves (Streptopelia decaocto) are thought to originate from India and they have colonized, throughout the centuries, the Middle East and, more recently, Mediterranean countries such as Italy and Spain. In the present paper we report of the isolation and characterization of Newcastle disease viruses (NDV) obtained from Eurasian collared doves during 2000-2001, and compare them to isolates obtained from feral pigeons (Columba livia) during the same period. All isolates could be classified as avian paramyxovirus type 1 (APMV1) and belonged to the pigeon variant group (PPMV1), as their haemagglutinating activity was inhibited by mAb 161/617 which is specific for PPMV1. The intracerebral pathogenicity indices ranged from 0.68 to 1.38 and all isolates contained multiple basic amino acids at the deduced cleavage site of the fusion protein, which is a typical feature of virulent viruses. Phylogenetic analysis of the isolates indicate that 18/20 of these form a separate cluster from the isolates obtained from pigeons in the same period. These findings suggest that different lineages are circulating in feral pigeon populations, and that a separate lineage affects Eurasian collared doves.