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.

Human Diseases Caused by Viruses

Jamestown Canyon Virus: An Emerging Arboviral Threat in Temperate Climates

Virus Origins

Virus Classification

What is a Viral Mutation?

Antiviral Immunity and COVID-19

What is Vertical Transmission?

What are Viral Clades?

Virus Purification Methods

What are Filoviruses?

Virus Eradication, Extinction, and Elimination Explained

See more featured articles »

What is the Difference Between Bacteria and Viruses?

Virus Microbiology

Are Viruses a Lifeform?

Virus Uses in Virology

Virus History

What Are Giant Viruses?

Virus Infection in Other Species

Latest Virus News and Research

The CDC just sidelined these childhood vaccines. Here’s what they prevent.

The federal government has drastically scaled back the number of recommended childhood immunizations, sidelining six routine vaccines that have safeguarded millions from serious diseases, long-term disability, and death.

6 Jan 2026

Unveiling Hidden Potential: Organoids for Disease Modeling in Neuroscience Research

In our latest interview, News-Medical speaks with Rosanna Zhang from ACROBiosystems about utilizing organoids for disease modeling in the field of neuroscience research.

From ACROBiosystems 6 Jan 2026

COVID-19 immunity stays specific and barely boosts protection against common cold coronaviruses

This study shows that SARS-CoV-2 infection and vaccination generate strong, highly specific spike-binding immune responses with only modest effects on immunity to endemic common cold coronaviruses. Pre-existing coronavirus immunity patterns remain largely intact, indicating that SARS-CoV-2 has integrated into the human viral landscape without broadly reshaping cross-reactive protection.

5 Jan 2026

Bat-borne virus linked to unexplained illnesses in Bangladesh

Infectious disease researchers have identified Pteropine orthoreoviruses (PRVs), a group of newly emergent bat-borne viruses, as the culprit for previously unexplained illness in five Bangladeshi patients, one of whom eventually died with unexplained illness.

5 Jan 2026

To knock down health-system hurdles between you and HIV prevention, try these 6 things

A couple of years ago, Matthew Hurley got the kind of text people fear.

5 Jan 2026

Ancient genomes reveal Iron Age origins of human herpesvirus 6

For the first time, scientists have reconstructed ancient genomes of Human betaherpesvirus 6A and 6B (HHV-6A/B) from archaeological human remains more than two millennia old.

4 Jan 2026

Viruses on plastic waste pose new antibiotic resistance risks

Plastic pollution does more than litter landscapes and oceans. According to a new perspective article published in Biocontaminant, viruses living on plastic surfaces may play an underrecognized role in spreading antibiotic resistance, raising concerns for environmental and public health worldwide.

31 Dec 2025

Advancing stem cell regeneration through animal-free culture systems

Intestinal Stem Cells (ISCs) derived from a patient's own cells have garnered significant attention as a new alternative for treating intractable intestinal diseases due to their low risk of rejection.

30 Dec 2025

Scientists capture real-time action of antiviral drugs on herpes

Harvard Medical School researchers have uncovered crucial insights into how an emerging class of antiviral drugs works.

30 Dec 2025

Researchers explore why Alzheimer's affects men and women differently

More than seven million Americans have Alzheimer's disease, and two-thirds of them are women, according to the Alzheimer's Association. The O'Banion Lab at the Del Monte Institute for Neuroscience at the University of Rochester has long been studying this disease and is looking more closely at the differences between male and female brains.

30 Dec 2025

Digital patient records improve survival in HIV treatment clinics

With 9.5% of its population estimated to be HIV-positive in 2019, Malawi has one of the highest rates of HIV prevalence in the world.

22 Dec 2025

Remodeling the tumor microenvironment to unlock CAR-T cell potential

Chimeric antigen receptor T (CAR-T) cell therapy has revolutionized hematologic cancer treatment, but its efficacy in solid tumors remains limited by poor infiltration into the complex tumor microenvironment (TME).

22 Dec 2025

Mpox clade Ib transmitted in a healthcare setting outside Africa

Mpox is a viral disease usually transmitted from animals to humans and symptoms include fever and skin rashes. In 2023, a new variant of monkeypox virus (MPXV), called clade Ib, emerged in Kamituga in the Democratic Republic of the Congo.

19 Dec 2025

ACE2 protein may play a protective role against high blood pressure and type 2 diabetes

A collaborative study from the MRC Laboratory of Medical Sciences (LMS) and Imperial College London has found that the protein ACE2 may play a protective role against two common conditions, high blood pressure and type-2 diabetes, which affect millions of people worldwide.

19 Dec 2025

Genes and biological networks that drive long COVID risk

This study merges causal genetics and network theory, revealing 32 genes linked to long COVID, offering insights for diagnostics and personalized therapies.

19 Dec 2025

Inside the FDA’s vaccine uproar

Six days after a senior FDA official sent a sweeping internal email claiming that covid vaccines had caused the deaths of "at least 10 children," 12 former FDA commissioners released an extraordinary warning in the Dec. 3 issue of the New England Journal of Medicine.

19 Dec 2025

Phages use small RNA to hijack bacterial cells and boost replication

As antibiotic-resistant infections rise and are projected to cause up to 10 million deaths per year by 2050, scientists are looking to bacteriophages, viruses that infect bacteria, as an alternative.

18 Dec 2025

Whooping cough cases rise sharply across the United States

Pertussis, also known as whooping cough, is a vaccination-preventable illness that has been on the rise in the United States. Following a several-year lull during the pandemic, cases of whooping cough rose sixfold in 2024 and remain high.

18 Dec 2025

New nanoparticle vaccines show promise against multiple deadly filoviruses

Filoviruses get their name from the Latin word "filum," meaning thread-a reference to their long, filamentous shape. This virus family contains some of the most dangerous pathogens known to science, including Ebola, Sudan, Bundibugyo and Marburg viruses.

18 Dec 2025

Rapid HIV viral load testing shows mixed effects on seeking care

According to the U.S. Centers for Disease Control and Prevention (CDC) and other sources, there are approximately 1.2 million people living with HIV in the United States, and another 1.2 to 2.2 million who are at highest risk for infection and could benefit from the preventive measure known as HIV pre-exposure prophylaxis (PrEP).

18 Dec 2025