Credit: James Gillray (12 June 1802)
Tobacco mosaic virus was the first virus to be identified, as an infectious agent that could pass through porcelain filters, as well as the first to be crystallised. It was among the earliest virus structures to be modelled successfully.
Credit: Thomas Splettstoesser (20 July 2012)
Credit: Neil Ranson (7 June 2011)
Credit: Fdardel (21 March 2009)
Credit: Boghog (28 June 2008)
Credit: C. Goldsmith (1984)
Credit: Jacobus Eussen (1745)
Credit: James Gathany (2009)
Aedes aegypti can transmit the chikungunya, dengue, yellow fever and Zika viruses. The mosquito is widespread in tropical and subtropical regions, with mosquito control being key to disease prevention.
Credit: United States Department of Agriculture (2000)
Credit: Cynthia Goldsmith
Credit: Eric Erbe & Christopher Pooley
Credit: Graham Beards (21 October 2008)
Credit: Unknown (1580–1350 BC)
Credit: Jean-Étienne Liotard (c. 1756)
Credit: Albert Edelfelt (1885)
Credit: James Gathany (28 February 2006)
Many small icosahedral viruses have capsids made up of multiple copies of just two proteins. The proteins aggregate into units called capsomeres, which have either pentagonal or hexagonal symmetry (as shown here).
Credit: Antares42 (4 September 2009)
Credit: Gerry Shaw (8 March 2012)
The common cold is the most frequent infectious disease. Despite the advice to "consult your physician" no antiviral treatment has been approved, and colds are only rarely associated with serious complications.
Credit: Federal Art Project (1937)
Some viruses, such as the T7 bacteriophage, encode their own RNA polymerase, the enzyme that makes messenger RNA based on a DNA template. The T7 enzyme has a single subunit, and is more like chloroplast and mitochondrial enzymes than those of bacteria or the cell.
Credit: Thomas Splettstoesser (25 June 2007)
Biosafety level 3 equipment is used for research with viruses such as influenza that can cause serious disease but for which treatment is available. The biosafety cabinet uses HEPA filters to filter viruses out of the air. This researcher is examining reconstructed 1918 pandemic influenza virus, or "Spanish flu".
Credit: CDC (2005)
Respiratory failure in bulbar and bulbospinal polio condemned many patients to one or two weeks in an "iron lung" or negative-pressure ventilator. The first ventilator designed for polio patients appeared in 1918; this model dates from the 1950s.
Credit: Hewa (December 2011)
Credit: Fvasconcellos (1 January 2007)
Chikungunya virus is an alphavirus transmitted by Aedes mosquitoes. The disease can cause severe joint pain, sometimes lasting for several months. Outbreaks have occurred across Africa, Asia and India, and in 2013–14, in South America and the Caribbean.
Credit: A2-33 (8 December 2013)
CCR5 is a human membrane protein that acts as a secondary receptor for HIV, enabling the viral and cell membranes to fuse. People with two copies of a mutated Δ32 form of CCR5 are naturally resistant to infection by most strains of HIV, and the normal form is the target of entry inhibitors such as maraviroc.
Credit: Thomas Splettstoesser (18 July 2012)
Megavirus chilensis is a very large DNA virus discovered in 2010. Until the discovery of Pandoravirus in 2013, it was the largest known virus, with its 440 nm diameter capsid being as large as some small bacteria. The capsid is enclosed in bacterial-like capsular material 75–100 nm thick.
Credit: Chantal Abergel (10 October 2011)
Haemagglutinin, a glycoprotein trimer on the influenza virus envelope, binds to the sialic acid-containing receptor on the host cell. After the virus has been engulfed into an endosome, it changes configuration, causing the viral and endosomal membranes to fuse, releasing the viral genome into the cytoplasm.
Credit: Jawahar Swaminathan (EBI) (16 November 2008)
Credit: Gerard of Cremona (c. 1250–60)
The castor bean tick, Ixodes ricinus, can transmit the tick-borne encephalitis virus. Ticks are common vectors for viruses, and other tick-borne diseases include Colorado tick fever and Crimean–Congo haemorrhagic fever.
Credit: Richard Bartz (24 April 2009)
Eastern equine encephalitis virus is an Alphavirus that is transmitted between birds and mammals, including humans and horses, by several mosquito species. The virus (coloured in red) is found in the mosquito salivary gland, and is injected into the new host when the insect feeds.
Credit: Fred Murphy, Sylvia Whitfield, CDC (1968)
The striping caused by tulip breaking virus, first described in 1576 by Carolus Clusius, was the second plant virus disease to be documented. The effects were much prized by 17th-century tulip growers.
Credit: Unknown (before 1640)
Credit: BernbaumJG (28 August 2014)