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

See more featured articles »

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

mNGS outperforms microbiological tests to diagnose bloodstream infections – BGI Insight

Next-generation sequencing (mNGS) leverages genetic testing advantage to save more lives; twice as effective at identifying infection cases.

From BGI Genomics 24 Mar 2023

U.S. maternal mortality rates rose during COVID-19 pandemic

A new study examines mortality related to pregnancy during the COVID-19 pandemic as compared pre-pandemic rates.

23 Mar 2023

Hidden "super spreader" spaces associated with a predominance of asymptomatic cases of dengue

For mosquito-borne diseases such as dengue fever, the abundance of the insects in places where people gather has long served as the main barometer for infection risk.

23 Mar 2023

The policy, and politics, of Medicare Advantage

Medicare Advantage, the private-sector alternative to original Medicare, now enrolls nearly half of all Medicare beneficiaries.

23 Mar 2023

Discovery suggests a new way to treat spinal muscular atrophy

Columbia researchers have discovered how a genetic defect leads to spinal muscular atrophy (SMA), a critical piece of information about the disease that neurologists have been seeking for decades.

23 Mar 2023

Candidate hepatitis C mRNA vaccine induces protective immunity in animal model

In a recent study published in the npj vaccines journal, researchers assessed the immune protection elicited by messenger ribonucleic acid (mRNA) vaccines delivering Hepatitis C virus (HCV) E1 and modified E2.

23 Mar 2023

Menin protein protects against aging and cognitive decline

In a recent study published in the journal PLoS Biology, researchers from the University of Xiamen, China, explored the role of the hypothalamic menin in driving aging and associated cognitive decay.

23 Mar 2023

Zoonotic agent Erysipelothrix rhusiopathiae caused mass mortality of harbor porpoises

In a recent article published in the Emerging Infectious Diseases Journal, researchers in the Netherlands described a mortality event that killed hundreds of harbor porpoises (Phocoena phocoena), a small cetacean, along the Netherlands coastline, in August 2021.

22 Mar 2023

Dampened mucosal response against SARS-CoV-2 in pregnant individuals

In a recent study posted to the medRxiv* preprint server, researchers examined associations between coronavirus disease 2019 (COVID-19) outcomes and mucosal antibody responses against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and viral RNA levels in pregnant individuals.

22 Mar 2023

SARS-CoV-2 infection damages CD8+ T cell response

In a recent study published in the journal Immunity, a team of researchers from the United States found that previous severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections reduce the activation and expansion of CD8+ T cells in response to coronavirus disease 2019 (COVID-19) vaccinations.

22 Mar 2023

Novel subset of memory B cells predicts long-lived antibody responses to influenza vaccination

Memory B cells play a critical role to provide long-term immunity after a vaccination or infection. In a study published in the journal Immunity, researchers describe a distinct and novel subset of memory B cells that predict long-lived antibody responses to influenza vaccination in humans.

22 Mar 2023

Texas A&M scientist explores how HVAC and building designs could mitigate pathogens' spread

Air flow in a room can impact the transmission of viruses like COVID-19.

22 Mar 2023

Animal studies show potential of new drug to curb painful hyperinflammation from osteoarthritis

A team of researchers at the Keck School of Medicine of USC have found a drug with the potential for curbing painful hyperinflammation from osteoarthritis, according to results of an animal study.

22 Mar 2023

Study reveals why COVID-19 subvariants spread rapidly among previously infected people

The COVID-19 pandemic has killed nearly 7 million people worldwide (1.1 million in the United States) and severely harmed many millions more, though vaccines and antiviral treatments measurably reduced the potential loss of life and health.

22 Mar 2023

Low-cost, universal oral COVID-19 vaccine prevents severe respiratory illness in hamsters

A UCLA-led team has developed an inexpensive, universal oral COVID-19 vaccine that prevented severe respiratory illness and weight loss when tested in hamsters, which are naturally susceptible to SARS-CoV-2.

22 Mar 2023

Disruption of the FcRn–IgG interaction may make AAV-based gene therapies effective

The use of a monoclonal antibody that reduced circulating IgG levels, led to a decrease in preexisting neutralizing antibodies (NAbs) to adeno-associated virus (AAV).

22 Mar 2023

End of covid emergency will usher in changes across the US health system

The Biden administration's decision to end the covid-19 public health emergency in May will institute sweeping changes across the health care system that go far beyond many people having to pay more for covid tests.

22 Mar 2023

Tetravalent COVID vaccine provides broad antibody responses against SARS-CoV-2 variants in animal model

In a recent study posted to the bioRxiv* preprint server, researchers in Italy and the United States evaluated the efficacy and immunogenicity of an adjuvanted tetravalent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike (S) protein subunit 1 (S1) COVID-19 vaccine.

21 Mar 2023

Prior COVID and vaccination generate superior hybrid immunity

In a recent article published in the journal Science Translational Medicine, researchers in France performed a long-term longitudinal analysis to demonstrate the benefits of hybrid immunity to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), i.e., induced by viral infection followed by vaccination.

21 Mar 2023

Next-gen Mpro inhibitor: Promising new drug candidate against Omicron and other SARS-CoV-2 variants

A recent Nature Signal Transduction and Targeted Therapy journal study demonstrated the potential antiviral activity of a new Mpro inhibitor (SY110) against SARS-CoV-2 Omicron and its sublineages.

21 Mar 2023