Virus

A virus is a microscopic infectious agent that can reproduce only inside a host cell. Viruses infect all types of organisms: from animals and plants, to bacteria and archaea. Since the initial discovery of tobacco mosaic virus by Martinus Beijerinck in 1898, more than 5,000 types of virus have been described in detail, although most types of virus remain undiscovered. Viruses are ubiquitous, as they are found in almost every ecosystem on Earth, and are the most abundant type of biological entity on the planet. The study of viruses is known as virology, and is a branch of microbiology.

What is a Virus?

A virus is a small infectious agent that can only replicate inside the cells of another organism.

Virus Purification Methods

Virus Classification

What are Filoviruses?

Virus History

What is Vertical Transmission?

What is a Viral Mutation?

Virus Origins

Human Diseases Caused by Viruses

Antiviral Immunity and COVID-19

Virus Uses in Virology

Jamestown Canyon Virus: An Emerging Arboviral Threat in Temperate Climates

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Virus Infection in Other Species

Virus Eradication, Extinction, and Elimination Explained

What are Viral Clades?

Are Viruses a Lifeform?

What is the Difference Between Bacteria and Viruses?

What Are Giant Viruses?

Virus Microbiology

Latest Virus News and Research

Cryo-EM study reveals dynamic structure of human norovirus

Human norovirus is the leading cause of acute gastroenteritis worldwide and is estimated to infect 600–700 million people each year.

4 Aug 2026

Genetic study explains global spread of invasive longhorned ticks

The Asian longhorned tick, Haemaphysalis longicornis, spreads serious pathogens, including severe fever with thrombocytopenia syndrome (SFTS) virus, Rickettsia, and Theileria, and its bite can cause a meat allergy in humans.

4 Aug 2026

Airplane wastewater pilot shows how airports could track pathogens across borders

Researchers showed that airplane wastewater from a shared US-UK transatlantic route could be collected and analyzed to detect respiratory and enteric pathogen genetic material. The pilot also captured SARS-CoV-2 lineage patterns, including earlier detection of XEC on UK-origin flights, while showing the need for harmonized assays and broader sampling.

4 Aug 2026

Penn State study identifies genetic regions linked to avian herpesvirus virulence

A highly contagious herpes virus causes Marek's disease, a deadly illness that mainly infects chickens. While it does not make people sick, the virus causes tumors and paralysis in chickens and, if unchecked, can spread rapidly through entire flocks.

3 Aug 2026

Study links ancient evolutionary pressures to severe COVID-19 risk

Every time a virus invades a person, it collides with thousands of years of human history. A study led by researchers at the USC Dornsife College of Letters, Arts and Sciences and Howard University suggests that some of the genes involved in the body's immune response today bear the marks of ancient battles with infectious diseases.

3 Aug 2026

Newly-discovered protein acts as off switch for human immune cells

Mayo Clinic researchers have identified a protein that cancer cells use to shut down the body's immune response, a discovery that could help scientists develop new treatments that make cancer immunotherapies more effective.

3 Aug 2026

Children remain more vulnerable to influenza despite protective antibody levels

Researchers analyzing 1,518 South African household participants found that higher pre-season antibody titers were associated with lower infection risk for three of four influenza viruses studied. Children remained more susceptible after accounting for measured exposure and antibody titers, while younger children shed viral RNA longer than older adults.

3 Aug 2026

Immune cell changes provide new insights into long COVID

Extreme fatigue, a racing pulse, shortness of breath, brain fog, aching joints-the symptoms of long COVID can vary widely, change unpredictably, and be difficult to even recognize as signs of the condition.

2 Aug 2026

Arginine boosts immune defenses against cancer and viral infections

The amino acid arginine helps to keep the human body humming, most notably by synthesizing proteins that carry out a range of cellular processes.

31 Jul 2026

Sino Biological launches SuperNuclease® Pro with free trial program

Sino Biological, Inc., a global leader in recombinant technology, announced the launch of SuperNuclease® Pro (Cat#: SSNP02).

From Sino Biological Inc. 31 Jul 2026

Program introduces Florida students to virology and pandemic preparedness

Thirty outstanding high school students from 18 communities across Florida arrived in Tampa last week for the Global Virus Network (GVN) Global Guardians for Pandemic Preparedness Program, curious about viruses and considering careers in science.

30 Jul 2026

Biotherapeutic metabolite repairs gut damage caused by HIV infection

Researchers at the UC Davis School of Medicine have identified a naturally occurring metabolite that repairs gut damage caused by HIV infection and significantly improves the effectiveness of antiretroviral therapy (ART) in the nonhuman primate model of HIV/AIDS.

30 Jul 2026

New OpenABE gene editor improves editing efficiency by up to 36 times

A joint research team led by Professor Daesik Kim (Department of Medicine, Sungkyunkwan University), along with Professor Yong-Sub Kim (University of Ulsan College of Medicine) and Professor Jae-Hyun Park (Sungkyunkwan University School of Medicine), has announced the development of 'OpenABE' (Open Adenine Base Editor).

30 Jul 2026

NIH funds mosquito genetics research to curb deadly disease spread

Mosquito-borne pathogens, including zika, yellow fever and other illnesses have serious and worldwide impacts on human health.

29 Jul 2026

NIH awards $2.4 million to study how maternal viral infections reprogram fetal immune development

The National Institute of Allergy and Infectious Diseases of the National Institutes of Health has awarded a new, five-year $2.4 million R01 grant to Dr. Jiahui Ding, assistant professor of obstetrics and gynecology at the Wayne State University School of Medicine's C.S. Mott Center for Human Growth and Development, to support research that aims to uncover how viral infections during pregnancy reprogram the developing immune system of the fetus, influencing susceptibility to infectious diseases throughout life.

29 Jul 2026

Scientists discover why mouse liver cells resist hepatitis E virus

Mouse liver cells are not a suitable host for hepatitis E viruses. The Virology department in Bochum has discovered why.

29 Jul 2026

Research reveals how a hidden immune cell army defends human lung tissue

New research led by scientists at La Jolla Institute for Immunology (LJI) and University of Liverpool (UOL) provides the first comprehensive look at how a hidden immune cell army defends the vast, vulnerable tissue of the human lungs.

28 Jul 2026

Remdesivir protects kidney and heart health in transplant recipients

Adults with kidney transplants who were treated for COVID-19 with the antiviral remdesivir within a week of COVID-19 diagnosis and who received at least three consecutive days of therapy were less likely than kidney transplant recipients who did not receive the antiviral to experience cardiovascular or kidney problems up to a year later, according to findings from a target trial emulation study that published in JAMA Network Open.

28 Jul 2026

Europe risks missing target to eliminate viral hepatitis by 2030

While Europe has made steady progress in preventing hepatitis B and C, with the prevalence of hepatitis B now at near-zero levels among children below five years old, an uneven implementation of key measures means that the region is set to miss the 2030 target to eliminate viral hepatitis as a public health threat, according to new data from the European Centre for Disease Prevention and Control (ECDC) on World Hepatitis Day.

28 Jul 2026

Dengue virus infects memory B cells to evade immune defenses

Researchers at the University of Vermont Robert Larner, M.D. College of Medicine and Upstate Medical University in Syracuse, NY, have discovered that dengue virus can infect and replicate inside memory B cells, immune cells traditionally understood to help protect the body from infection.

27 Jul 2026