Tobacco mosaic virus (TMV) is an RNA virus in the Virgaviridae family that infects a wide range of plants, including tobacco, tomato, pepper, other members of the Solanaceae family, and cucumber. The rod-shaped virus particle is around 300 nm long and 18 nm in diameter, and consists of a helical capsid made from 2130 copies of a single coat protein, which is wrapped around a positive-sense single-stranded RNA genome of around 6400 bases. The coat protein and RNA can self-assemble to produce infectious virus.

Infection often causes characteristic patterns, such as "mosaic"-like mottling and discoloration on the leaves, but is almost symptomless in some host species. TMV causes an economically important disease in tobacco plants. Transmission is frequently by human handling, and prevention of infection involves destroying infected plants, hand washing and crop rotation to avoid contaminated soil. TMV is one of the most stable viruses known. The fact that it does not infect animals and can readily be produced in gramme amounts has led to its use in numerous pioneering studies in virology and structural biology. TMV was the first virus to be discovered and the first to be crystallised.

• ...that flow cytometry bioinformaticians use methods from computational statistics and machine learning to analyse single cell data gathered by flow cytometry for cancer and HIV/AIDS research (output pictured)?
• ...that Sierra Leonean physician Aniru Conteh saved thousands of lives from Lassa fever before dying from the disease himself?
• ...that early in the history of veterinary medicine in the Philippines, a cattle plague killed 600,000 animals from 1901 to 1902 alone?
• ...that the isolation of antibodies and flu viruses from birds on Tryon Island, a coral cay off the coast of Queensland, Australia, led to the development of antiviral drugs, such as oseltamivir?
• ...that the Plague of Athens devastated ancient Athens in 430 BC, perhaps leading ultimately to the city's defeat in the Peloponnesian War?

Aniru Sahib Sahib Conteh (6 August 1942 – 4 April 2004) was a Sierra Leonean physician and expert on the clinical treatment of Lassa fever, a viral haemorrhagic fever endemic to West Africa.

He joined the Centers for Disease Control and Prevention Lassa fever programme in Segbwema, first as superintendent and then as clinical director. After the Sierra Leone Civil War began in 1991, Conteh moved to the Kenema Government Hospital, where he spent the next two decades running the only dedicated Lassa fever ward in the world. He collaborated with the British charity Merlin to promote public health in Sierra Leone through education and awareness campaigns intended to prevent Lassa fever. With little funding and few supplies, he successfully reduced mortality rates and saved many lives until an accidental needlestick injury led to his own death from the disease in 2004.

Conteh received renewed public attention in 2009 as the hero of Ross I. Donaldson's memoir, The Lassa Ward.

5 June 1981: First report of HIV/AIDS (symbol pictured) appeared in medical literature

6 June 1997: Gene silencing in plants shown to be a viral defence mechanism

7–13 June 1962: Donald Caspar and Aaron Klug proposed the quasi-equivalence principle of virus structure

7–13 June 1962: André Lwoff proposed a viral classification scheme based on nature of genome, type of symmetry and presence of envelope

7–13 June 1962: George Hirst proposed that the influenza virus genome is segmented

9 June 1981: The American Society for Virology was founded

13 June 2012: First case of Middle East respiratory syndrome coronavirus (MERS-CoV) occurred in Saudi Arabia

18 June 1981: A vaccine against foot-and-mouth disease was the first genetically engineered vaccine

21 June 1996: Nevirapine approved, first NNRTI for HIV/AIDS

26 June 1993: Clinical trial of hepatitis B virus drug fialuridine terminated; the drug caused several fatalities due to lactic acidosis

28 June 2011: FAO declared rinderpest eradicated

30 June 1985: Ryan White was denied re-admittance to his school after an AIDS diagnosis, in a case that changed public perceptions of the disease

The first Ebola vaccine was approved in 2019. Developed by the Public Health Agency of Canada, rVSV-ZEBOV is based on an attenuated recombinant vesicular stomatitis virus, genetically modified to express a surface glycoprotein of Zaire ebolavirus, and is estimated to be 97.5% effective. In the Kivu Ebola epidemic of 2018–20, a ring vaccination strategy was employed to protect direct and indirect contacts of infected people, as well as health workers, and around 300,000 people were vaccinated with rVSV-ZEBOV. A second vaccine was approved in 2020; this uses two different doses – a vector based on human adenovirus serotype 26 used to prime, boosted around eight weeks later by modified vaccinia Ankara (based on a heavily attenuated vaccinia virus) – and is not suitable for response to an outbreak. The efficacy is unknown. Multiple other vaccine candidates are in development to prevent Ebola, including replication-deficient adenovirus vectors, replication-competent human parainfluenza 3 vectors, and virus-like nanoparticle preparations.

Subcategories of virology: