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

Study demonstrates successful gene therapy for maple syrup urine disease

A study led by UMass Chan researchers demonstrated that a gene therapy to correct a mutation that causes maple syrup urine disease (MSUD) prevented newborn death, normalized growth, restored coordinated expression of the affected genes and stabilized biomarkers in a calf as well as in mice.

28 Feb 2025

New target identified for preventing cold sores and genital herpes

Scientists have a new target to prevent cold sores after University of Virginia School of Medicine researchers discovered an unexpected way the herpes virus re-activates in the body.

28 Feb 2025

Atlantia Clinical Trials: Investigating the interrelation of microbiology and immunology

To be decided by the editor

From Atlantia Clinical Trials 28 Feb 2025

Hospitalized COVID patients face long-term risks

A nationwide study has revealed that survivors of COVID-19 hospitalization face an increased risk of death or organ-related disorders for up to two-and-a-half years after discharge.

28 Feb 2025

WHO Director-General issues revised recommendations on mpox emergency

The Director-General of the World Health Organization (WHO), following the third meeting of the International Health Regulations (2005) (IHR) Emergency Committee regarding the upsurge of mpox 2024, held on 25 February 2025, from 12:00 to 17:00 CET, concurs with its advice that the event continues to meet the criteria of a public health emergency of international concern and, considering the advice of the Committee, he is hereby issuing a revised set of temporary recommendations.

27 Feb 2025

Study reveals role of CB1 receptors in resilience to chronic stress

When faced with chronic stress, why do some people develop anxiety and depressive symptoms while others show resilience?

27 Feb 2025

EU project aims to combat dangerous viruses with molecular interventions

Targeted molecular interventions in the replication cycle and the immune recognition of viruses are intended to prevent viral entry into cells and virus replication.

27 Feb 2025

Scientists uncover how a sugar shield in brain blood vessels protects against aging and disease

Researchers reveal that the loss of mucin-type O-glycosylation in the brain endothelial glycocalyx weakens the blood-brain barrier, leading to increased permeability, neuroinflammation, and cognitive decline in aging and neurodegenerative diseases.

27 Feb 2025

Study highlights increase in VZV-induced CNS infections and dementia risk

Researchers from Fujita Health University, Japan, observed a rise in adult central nervous system (CNS) infections, primarily aseptic meningitis caused by the varicella zoster virus (VZV), post-2019. The researchers highlighted the potential of zoster vaccination to reduce CNS infections.

27 Feb 2025

Air sampling detects 70–90% of poultry viruses and reveals 50 more hidden threats

Researchers found that environmental sampling in live-bird markets detects 70–90% of poultry viruses, often outperforming traditional swab methods, and identified 50 additional viruses, some from non-avian sources.

26 Feb 2025

Discovery of new bat flu strain with potential to infect other species

Scientists have identified a novel influenza A virus (H18N12) in fishing bats in the Colombian Caribbean, revealing genetic reassortment events that impact viral adaptability and host transmission.

25 Feb 2025

Can AI predict the next pandemic? A new study says yes

Researchers explore how artificial intelligence is transforming infectious disease modeling

25 Feb 2025

Study finds strong evidence that bird flu spreads through the air between farms

Researchers provided genetic and meteorological evidence suggesting that windborne transmission of HPAI H5N1 over 8 km is possible, highlighting its role in poultry farm outbreaks.

24 Feb 2025

Machine learning algorithm decodes immune system’s hidden data for disease detection

Your immune system harbors a lifetime's worth of information about threats it's encountered - a biological Rolodex of baddies.

24 Feb 2025

Study shows how herpes viruses contribute to Alzheimer's disease in aging brains

Researchers from Cleveland Clinic's Genome Center outlined the pathway human herpes simplex virus-1 (HSV1) can use to contribute to Alzheimer's disease in aging brains.

24 Feb 2025

T cells play key role in protecting children from severe dengue

Children who experience multiple cases of dengue virus develop an army of dengue-fighting T cells, according to a new study led by scientists at La Jolla Institute for Immunology (LJI).

24 Feb 2025

CMV infection found to worsen necrotizing enterocolitis in preterm infants

Researchers say they found that infection with a common virus that can be transmitted from mother to fetus before birth significantly worsens an often-fatal complication of premature birth called necrotizing enterocolitis (NEC) in experiments with mice.

24 Feb 2025

Venom is everywhere: Study examines hidden toxin delivery systems across life forms

Forget snakes and spiders—a new review details venomous plants, fungi, and even bacteria, proving that nature's deadliest secret weapon is more widespread than we ever imagined.

23 Feb 2025

Why over 5 billion people still lack access to life-saving medical oxygen

The Lancet Global Health Commission highlights severe inequities in medical oxygen access, urging systemic reforms to ensure universal availability and affordability.

23 Feb 2025

Zika virus hijacks tunneling mechanism to infect placental cells

Infection with Zika virus in pregnancy can lead to neurological disorders, fetal abnormalities and fetal death. Until now, how the virus manages to cross the placenta, which nurtures the developing fetus and forms a strong barrier against microbes and chemicals that could harm the fetus, has not been clear.

22 Feb 2025