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.

What is the Difference Between Bacteria and Viruses?

Virus History

Virus Origins

Virus Microbiology

Virus Classification

Virus Infection in Other Species

Human Diseases Caused by Viruses

Virus Uses in Virology

Virus Purification Methods

What are Filoviruses?

Antiviral Immunity and COVID-19

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What is Vertical Transmission?

What is a Viral Mutation?

What are Viral Clades?

Are Viruses a Lifeform?

What Are Giant Viruses?

Virus Eradication, Extinction, and Elimination Explained

Latest Virus News and Research

Annual COVID-19 boosters crucial for immunocompromised individuals

New research findings provide solid evidence that annual COVID-19 vaccine booster doses continue to be advisable for certain immunocompromised people, researchers at McGill University say.

1 Apr 2025

New drug restores vision by regenerating retinal nerves

Vision is one of the most crucial human senses, yet over 300 million people worldwide are at risk of vision loss due to various retinal diseases.

1 Apr 2025

Research highlights rising risk of human-to-human mpox transmission

Mpox has the potential to become a significant global health threat if taken too lightly, according to scientists at the University of Surrey.

1 Apr 2025

Montana may start collecting immunization data again amid US measles outbreak

When epidemiologist Sophia Newcomer tries to evaluate how well Montana might be able to ward off the measles outbreak spreading across the U.S., she doesn't have much data to work with.

1 Apr 2025

Artificial intelligence tool predicts virus outbreak hotspots

A new artificial intelligence tool could aid in limiting or even prevent pandemics by identifying animal species that may harbor and spread viruses capable of infecting humans.

31 Mar 2025

Does COVID-19 affect heart rate variability after recovery?

Researchers determine the impact of mild COVID-19 on heart rate variability.

31 Mar 2025

AI-based tool aims to improve mosquito identification for disease control

Morphology is the study of the form and structure of organisms, including their physical characteristics such as shape, size and arrangement of parts.

28 Mar 2025

New research reveals factors influencing steroid hormone levels in healthy adults

Steroid hormone levels in healthy adults are influenced by oral contraceptives and smoking, as well as other lifestyle choices and factors such as biological sex and age, according to new research that has just been published in leading international journal Science Advances.

28 Mar 2025

UTA expert discusses the latest developments of measles outbreak in Texas

Measles is a highly contagious disease that was declared eliminated from the U.S. by the World Health Organization 25 years ago due to the success of vaccination efforts.

28 Mar 2025

Gender affirming hormone therapy reduces HIV risk for transgender people

Transgender people receiving gender-affirming hormone therapy have a 37% lower chance of acquiring HIV, and for people living with HIV, hormone therapy appears to offer a 44% lower chance of the virus remaining detectable in blood, according to a University of Michigan study.

27 Mar 2025

Study points to single respiratory virus as cause of Kawasaki disease

Research from Stanley Manne Children's Research Institute at Ann & Robert H. Lurie Children's Hospital of Chicago strongly suggests that Kawasaki disease is caused by a single respiratory virus that is yet to be identified.

27 Mar 2025

New AI method could predict emerging SARS-CoV-2 variants

It's been five years since COVID-19 was declared a global pandemic. As SARS-CoV-2 shifts to endemic status, questions about its future evolution remain.

27 Mar 2025

Two aldehyde-based disinfectants proven effective against hepatitis A virus

The hepatitis A virus (HAV) is one of the main causes of viral hepatitis and is responsible for an estimated 159,000 infections and 39,000 deaths each year.

27 Mar 2025

Transforming genetic deafness treatment with base editing

Congenital hearing loss refers to impaired auditory function that occurs due to genetic causes. GJB2 is the gene responsible for approximately half of all cases of hereditary hearing loss.

27 Mar 2025

Researchers develop a reverse genetics system for African swine fever virus

Researchers from the J. Craig Venter Institute (JCVI), the Friedrich-Loeffler-Institut (FLI), and the International Livestock Research Institute (ILRI) have developed a reverse genetics system for African swine fever virus (ASFV).

26 Mar 2025

COVID-derived molecular mimics may be involved in triggering autoimmunity

COVID infection has been linked to higher risk of autoimmune disorders, including rheumatoid arthritis and type 1 diabetes.

26 Mar 2025

COVID-19 vaccines may cut risk of long COVID

Full COVID-19 vaccination may reduce post-COVID-19 condition risk by 27%, though more research is needed, especially for children and immunocompromised groups.

26 Mar 2025

Report shows alarming measles resurgence in Europe and US

A recent report shows cases of measles across the World Health Organization's European Region, which includes the UK, are the highest they've been for more than 25 years. At the same time, large outbreaks of measles in the US have led to the first measles deaths there since 2015.

26 Mar 2025

Study reveals distinct infection strategies of Zika and dengue viruses

Zika virus and dengue virus are very close relatives. Both are mosquito-borne flaviviruses, and both specialize in infecting a host's dendritic cells.

25 Mar 2025

Yale study unlocks potential of lupus-related antibody to target cold tumors

Yale scientists have discovered a promising way to trigger immune responses against certain tumors, using a lupus-related antibody that can slip, undetected, into "cold" tumors and flip on an immune response that has been turned off by cancer.

25 Mar 2025