Not a single case of influenza has been detected by public health officials in England for the past seven weeks, with infection rates at historic lows amid the ongoing Covid-19 restrictions.
The social restrictions brought in to curb transmission of coronavirus, combined with increased uptake of the flu vaccine, have both been credited with driving down infections.
An alternative possibility to social distancing causing the drop in flu infections:
“Our study shows that during coinfections, one virus can block another simply by being the first to infect the available host cells; there is no need for viral interference through immune response interactions. We use the model to calculate the duration of detectable coinfection and examine how it varies as initial viral dose and time of infection are varied. We find that rhinovirus, the fastest-growing virus, reduces replication of the remaining viruses during a coinfection, while parainfluenza virus, the slowest-growing virus is suppressed in the presence of other viruses.”
“In this study, we tested whether IAV infection could affect the subsequent SARS-CoV-2 infection in both cultured cells and mice. Our results demonstrate that preinfection with IAV strongly enhances the infectivity of SARS-CoV-2 by boosting viral entry into cells and elevating the viral load, leading to more severe lung damage in infected mice. These data suggest a clear auxo-action of IAV on SARS-CoV-2 infection, which underscores the great risk of influenza virus and SARS-CoV-2 coinfection to public health.”
“..the most immediate threat to public health is recombination of other coronaviruses with SARS-CoV-2. Such recombination could readily produce further novel viruses with both the infectivity of SARS-CoV-2 and additional pathogenicity or viral tropism from elsewhere in the Coronaviridae”
The most prominent result for a SARS-CoV-2 recombination host is the domestic pig (Sus scrofa), having the most predicted associations of all included non-human mammals. The pig is a major known mammalian coronavirus host, harbouring both a large number of observed coronaviruses, as well as a wide diversity. Given the large number of predicted viral associations presented here, the pig’s close association to humans, its known reservoir status for many other zoonotic viruses, and its involvement in genetic recombination of some of these viruses, the pig is predicted to be one of the foremost candidates an important recombination host.
“The patient had co-infection by two SARS-CoV-2 lineages, which were affiliated in distinct clades and diverging by six variants. The 20A lineage was absolute at the diagnosis (shared with the patient’s mother), but nine days later, the 20B lineage had 3% frequency, and two months later, the 20B lineage had 100% frequency”
“We were the first to identify two independent events of co-infection caused by the occurrence of B.1.1.28 (E484K) with either B.1.1.248 or B.1.91 lineages. Also, clustering analysis revealed the occurrence of a novel cluster of samples circulating in the state (named VUI-NP13L) characterized by 12 lineage-defining mutations.”