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 Are Giant Viruses?

Virus Uses in Virology

Virus Purification Methods

Antiviral Immunity and COVID-19

Virus Classification

What is a Viral Mutation?

Jamestown Canyon Virus: An Emerging Arboviral Threat in Temperate Climates

Virus Infection in Other Species

What is the Difference Between Bacteria and Viruses?

What is Vertical Transmission?

Virus History

See more featured articles »

Human Diseases Caused by Viruses

What are Filoviruses?

What are Viral Clades?

Virus Microbiology

Virus Eradication, Extinction, and Elimination Explained

Are Viruses a Lifeform?

Virus Origins

Latest Virus News and Research

Exposure to port-derived particles facilitates the replication of COVID-19 and cold viruses

Air pollution from cruise ships could be damaging the health of people living in port cities by increasing inflammation and susceptibility to viruses such as the common cold and COVID-19.

10 Jul 2026

Discovery could pave the way for future vaccines against genital herpes

Researchers at the University of Gothenburg have identified a key protein that allows the virus that causes genital herpes to get into the nervous system.

9 Jul 2026

Review highlights traditional Chinese medicine for Chikungunya fever management

Chikungunya fever, caused by Chikungunya virus (CHIKV), has re‑emerged as a major global health threat. The 2025 outbreak in Guangdong, China – the largest local epidemic ever recorded – marks a critical epidemiological turning point.

9 Jul 2026

GLP-1 drugs may reduce lung scarring from Long COVID in diabetic patients

GLP-1 agonists have become popular treatments for weight loss and type 2 diabetes, and newer studies suggest other health benefits as well.

9 Jul 2026

New genetic screening method unlocks insights into human development

A new genetic screening method allows researchers to efficiently modulate individual genes across entire tissues and provides new insights into human development.

9 Jul 2026

Smoking shows no major impact on the eye microbiome in small study

A small study found no evidence that smoking causes large or consistent shifts in the ocular surface microbiome or tear proteome. The authors caution that subtle smoking-related effects cannot be ruled out, given the small cohort and the ocular surface's low-biomass, contamination-sensitive microbial niche.

8 Jul 2026

Weill Cornell Medicine receives federal grant to study new gene therapy for Alzheimer's disease

The National Institute on Aging of the National Institutes of Health has awarded a five-year grant initially worth $8.37 million for Weill Cornell Medicine researchers to study a new gene therapy for Alzheimer's disease in people who have a high genetic risk of developing the condition.

8 Jul 2026

New gene therapy strategy uses the brain's own glymphatic transport system for drug delivery

A new study describes a gene therapy strategy that uses the brain's own glymphatic transport system to distribute engineered viral vectors throughout the brain.

8 Jul 2026

Bio-Rad launches Vericheck ddPCR Kits compatible with QX700 platform for biopharma quality control and cell and gene therapy workflows

Bio-Rad Laboratories, Inc., a global leader in life science research and clinical diagnostics products, today announced the launch of the QX700 System-compatible Vericheck ddPCR Kit portfolio for critical quality control (QC) workflows in advanced cell and gene therapy development and other biopharma applications.

From Bio-Rad Laboratories 8 Jul 2026

New viral insights lay foundation for treating infection with JC polyomaviruses

In people with severely compromised immune systems, the JC polyomavirus can trigger a currently untreatable, usually fatal brain disease.

6 Jul 2026

New HIV vaccine successfully generates broadly neutralizing antibodies in primates

A new HIV vaccine developed by La Jolla Institute for Immunology (LJI), Scripps Research scientists, and IAVI has the potential to protect humans from developing HIV infection and AIDS.

6 Jul 2026

Study reveals how manufacturing methods affect herbal medicine potency

In a study published in Signal Transduction and Targeted Therapy, the researchers used MIR2911, a plant microRNA enriched in honeysuckle, as a proof-of-concept example.

3 Jul 2026

WHO launches PARTNERS clinical trial for Bundibugyo virus treatments

In a major international effort to evaluate potential treatments for Ebola disease due to Bundibugyo virus (BVD), the PARTNERS clinical trial has opened enrolment today for patients in the Democratic Republic of the Congo.

3 Jul 2026

WHO lists first molecular diagnostic test for Bundibugyo virus

Today, the World Health Organization (WHO) has added the first molecular diagnostic test for Bundibugyo virus (BDBV) to its Emergency Use Listing (EUL).

3 Jul 2026

Foodborne threats demand stronger pandemic planning, review says

A Perspective review in npj Science of Food argues that pandemics can weaken food safety systems even when the pathogen is not foodborne. The authors call for One Health planning that integrates food safety into pandemic preparedness, surveillance, laboratory capacity, workforce readiness, and regulation.

2 Jul 2026

First-in-class experimental CAR T-cell therapy shows promise against solid tumors

Researchers with the Charbonneau Cancer Institute at the University of Calgary and McMaster University have identified a unique target present on a specific group of solid cancerous tumors.

2 Jul 2026

Low-cost B-cell depleting therapy is as effective as standard treatment for multiple sclerosis

A Norwegian Swedish clinical trial published in the New England Journal of Medicine (NEJM) demonstrates that rituximab, a low-cost B-cell depleting therapy, is as effective as ocrelizumab in newly diagnosed relapsing multiple sclerosis (MS).

2 Jul 2026

Decades of research reveal surprising secrets about hantavirus evolution

Thirty years ago, it was our common sense understanding that hantavirus does not and perhaps cannot spread from human to human. It turns out there is one exception: a strain called the Andes virus.

2 Jul 2026

KFF poll finds vaccine myths reach many Americans but convince few

KFF’s 2026 tracking poll found that many U.S. adults have heard common vaccine myths, including false claims about MMR, COVID-19, mRNA vaccines, and measles vaccines. Fewer adults strongly believe these myths, but a large, uncertain “malleable middle” remains, especially among those without a trusted health care provider, frequent social media users, some AI health-information users, and parents who delayed or skipped childhood vaccines.

1 Jul 2026

LEF1 and niche-derived factors regulate T cell stemness across chronic diseases

T cells are an elite fighting force of the immune system, seeking out and destroying diseased cells. But in a prolonged campaign against a chronic condition - like a viral infection, or cancer - the body needs a steady supply of these killer troops.

1 Jul 2026