• Skip to main content
  • Skip to primary sidebar
virology blog

virology blog

About viruses and viral disease

influenza virus

TWiV 931: Driven to immunodistraction

28 August 2022 by Vincent Racaniello

TWiV reviews the genetic characterization of a new strain of type 2 oral polio vaccine and its implications for eradication, and how a polymorphism in humans comprising a single amino acid change in an antibody molecule regulates vaccine elicitation of broadly neutralizing antibodies against influenza virus HA.

Hosts: Vincent Racaniello, Dickson Despommier, Alan Dove, Kathy Spindler, and Brianne Barker

Click arrow to play
Download TWiV 931 (73 MB .mp3, 121 min)
Subscribe (free): Apple Podcasts, Google Podcasts, RSS, email

Become a patron of TWiV!

Show notes at microbe.tv/twiv

Filed Under: This Week in Virology Tagged With: broadly neutralizing antibody, influenza virus, neurovirulence, nOPV2, poliovirus, vaccine, viral, virology, virus, viruses, wastewater

TWiV 878: Shape matters sometimes

20 March 2022 by Vincent Racaniello

TWiV revisits chronic wasting disease of cervids and the ability of the prions to infect meadow voles and raccoons, and the suggestion that stochastic assembly of influenza virus particles may play a role in phenotypic diversity.

Hosts: Vincent Racaniello, Dickson Despommier, Rich Condit, and Amy Rosenfeld

Click arrow to play
Download TWiV 878 (75 MB .mp3, 124 min)
Subscribe (free): Apple Podcasts, Google Podcasts, RSS, email

Become a patron of TWiV!

Show notes at microbe.tv/twiv

Filed Under: This Week in Virology Tagged With: cervid, chronic wasting disease, influenza virus, prion, transmissible spongiform encephalopathy, viral, virology, virus, viruses

Wuhan spiny eel influenza virus

28 October 2021 by Vincent Racaniello

Influenza B viruses, unlike influenza A viruses, do not cause pandemics. There are many non-human animal reservoirs of influenza A viruses which provide gene segments that go towards making reassortant viruses that can infect humans. Influenza B viruses do not appear to have an animal reservoir other than humans – they have been isolated from seals but these appear to be human viruses. Influenza viruses discovered in fish and amphibians, however, are clearly not human viruses.

A sampling of viruses in amphibians, fish, and reptiles revealed influenza B virus sequences in the spiny eel, hagfish, and Asiatic toad. An important question to answer is whether these putative viruses have to potential to donate RNA segments to viruses that infect humans. To answer this question, functions of the HA and HA proteins of Wuhan spiny eel influenza virus (WSEIV) were studied. These two glycoproteins, found in the viral membrane, are important determinants of host range.

The HA protein of influenza A and B viruses binds the cell receptor, sialic acid, and catalyzes membrane fusion. These viruses can also hemagglutinate red blood cells. The HA protein of WSEIV does not hemagglutinate red blood cells. Influenza virus HA binds alpha2,3 and alpha2,6 linked silica acids, but the WSEIV HA binds alpha2,3 sialic acids only when they are present in a ganglioside – a sialic acid-containing lipid. HA cleavage by cell proteases is required for fusion, but none of the human airway proteases that cleave influenza A or B virus HA cleave WSEIV HA. Furthermore, the HA of WSEIV cannot catalyze fusion of cells in culture. It is therefore functionally divergent from other influenza virus HA proteins.

In contrast, the NA protein of WSEIV does have neuraminidase activity – the ability to cleave sialic acid from glycoproteins – as do other influenza virus NA proteins. Furthermore, the NA of WSEIV has similar biochemical properties as the NA of other influenza viruses, and its activity can be inhibited by the antiviral drug Tamiflu.

Both the HA and NA proteins of WSEIV are antigenically diverged from other influenza viruses – they do not react with a panel of monoclonal antibodies directed against influenza B viruses. Furthermore, human sera do not appear to contain antibodies that bind the WSEIV HA or NA, indicating that humans have not been infected with this virus.

These data show that WSEIV is a bona fide influenza virus; the HA is functionally diverged from that of other influenza viruses while the NA has similar properties. Based on these observations it seems unlikely that the WSEIV HA RNA segment could be part of a virus that infects humans. However, the similarity of the WSEIV NA with those of other influenza viruses suggest that it might be compatible with reproduction in humans. The fact that there is little antigenic conservation of the WSEIV glycoproteins with those of other influenza viruses means that an influenza virus carrying them would encounter an immunologically naive human population. Sound familiar?

An important lesson of this work is that we have woefully undersampled wildlife for viruses. Consequently, conclusions about what viruses are found in which hosts are likely to be wrong.

Filed Under: Basic virology Tagged With: HA, influenza B virus, influenza virus, pandemic, viral, virology, virus, viruses, Wuhan spiny eel virus

TWiV 670: Coronavirus vaccine preparedness with Kizzmekia Corbett

8 October 2020 by Vincent Racaniello

Kizzmekia Corbett joins TWiV to review her career and her work on respiratory syncytial virus, influenza virus, and coronaviruses and coronavirus vaccines, including her role in development and testing of a spike-encoding mRNA vaccine, and then we review the Nobel Prize for discovery of hepatitis C virus.

Click arrow to play
Download TWiV 670 (76 MB .mp3, 127 min)
Subscribe (free): iTunes, Google Podcasts, RSS, email

Become a patron of TWiV!

Show notes at microbe.tv/twiv

Filed Under: This Week in Virology Tagged With: coronavirus, COVID-19, influenza virus, mRNA-1273, pandemic, prefusion conformation, respiratory syncytial virus, SARS-CoV-2, spike, vaccine, viral, virology, virus, viruses

TWiV 636: Georgia State viral

9 July 2020 by Vincent Racaniello

From Georgia State University, Vincent speaks with Chris, Andrew, Priya, and Richard about their careers and their work on Ebolaviruses, rotavirus, and antiviral drug development.

Click arrow to play
Download TWiV 636 (68 MB .mp3, 113 min)
Subscribe (free): iTunes, Google Podcasts, RSS, email

Become a patron of TWiV!

Show notes at microbe.tv/twiv

Filed Under: This Week in Virology Tagged With: antiviral drug, ebolavirus, IFN, immune modulation, influenza virus, innate immunity, measles virus, respiratory syncytial virus, rotavirus, viral, virology, virus, viruses

Antibiotics blunt the antibody response to influenza vaccine

19 December 2019 by Vincent Racaniello

influenza vaccineThe human gut microbiome appears to play diverse roles in host physiology, metabolism, and immunity. Most conclusions about what the trillions of bacteria in our intestines actually do come from studies in mice, or correlative studies in humans. An exception is an investigation in humans which shows that antibiotic-mediated alteration of the fecal microbiome* interferes with the antibody response to influenza vaccine.

[Read more…] about Antibiotics blunt the antibody response to influenza vaccine

Filed Under: Basic virology, Information Tagged With: antibiotics, antibody response, influenza vaccine, influenza virus, microbiome, trivalent inactivated influenza vaccine, viral, virology, virus, viruses

  • Go to page 1
  • Go to page 2
  • Go to page 3
  • Interim pages omitted …
  • Go to page 8
  • Go to Next Page »

Primary Sidebar

by Vincent Racaniello

Earth’s virology Professor
Questions? virology@virology.ws

With David Tuller and
Gertrud U. Rey

Follow

Facebook, Twitter, YouTube, Instagram
Get updates by RSS or Email

Contents

Table of Contents
ME/CFS
Inside a BSL-4
The Wall of Polio
Microbe Art
Interviews With Virologists

Earth’s Virology Course

Virology Live
Columbia U
Virologia en Español
Virology 101
Influenza 101

Podcasts

This Week in Virology
This Week in Microbiology
This Week in Parasitism
This Week in Evolution
Immune
This Week in Neuroscience
All at MicrobeTV

Useful Resources

Lecturio Online Courses
HealthMap
Polio eradication
Promed-Mail
Small Things Considered
ViralZone
Virus Particle Explorer
The Living River
Parasites Without Borders

Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.