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

WHO overturns dogma on airborne disease spread. The CDC might not act on it.

The World Health Organization has issued a report that transforms how the world understands respiratory infections like covid-19, influenza, and measles.

1 May 2024

Avian flu crosses species, infecting cats and cattle in Texas and Kansas

A study in the CDC's Emerging Infectious Disease Journal reports the spread of H5N1 avian influenza among cats and dairy cattle in Texas and Kansas, showing systemic illness in cattle and significant fatalities in cats exposed to the virus through infected milk.

1 May 2024

Electric pulses boost gene therapy uptake in liver cells

In an effort to improve delivery of costly medical treatments, a team of researchers in electrical engineering at the University of Wisconsin–Madison has developed a stimulating method that could make the human body more receptive to certain gene therapies.

30 Apr 2024

Study shows continued willingness to get vaccinated across 23 countries

A substantial proportion of the world's population remains willing to get vaccinated against diseases including COVID-19, according to a new survey across 23 countries that represent more than 60% of the world's population.

30 Apr 2024

Updated vaccine provides strong immune response against previous and emerging SARS-CoV-2 variants

New research using live SARS-CoV-2 virus reveals an updated vaccine provides a strong immune response against previous strains and emerging variants.

29 Apr 2024

New SARS-CoV-2 KP.2 variant defies vaccines with higher spread, study warns

Study on the bioRxiv server reports that the SARS-CoV-2 KP.2 variant, despite lower infectivity, shows significant immune resistance and higher transmissibility compared to other variants, potentially impacting global public health and vaccine efficacy.

29 Apr 2024

New Kaposi sarcoma mouse model could be key to drug development

Researchers at UNC Lineberger Comprehensive Cancer Center, after decades of research efforts, have developed a mouse model of Kaposi sarcoma that could be key to the development of new drugs to treat the disease.

29 Apr 2024

Do SARS-CoV-2 infections cause long-term loss of smell and taste?

The long-term smell and taste-associated outcomes of coronavirus disease 2019 (COVID-19) using validated psychophysical tests.

29 Apr 2024

Expert warns of the continuous dangers posed by polio and other enteroviruses

Consistently high vaccination rates and global health surveillance programs have helped eliminate poliomyelitis (polio) in almost all countries of the world, except Afghanistan and Pakistan.

28 Apr 2024

Study rethinks immune system strategies to boost vaccine effectiveness

A recent Cell journal review explores key immunological assumptions to enhance our understanding of vaccine design, autoimmune responses, and immune system pathology, aiming to refine intervention strategies and theoretical frameworks in immunology.

28 Apr 2024

Ohio State study reveals bacterial defense mechanism against phages

One of the many secrets to bacteria's success is their ability to defend themselves from viruses, called phages, that infect bacteria and use their cellular machinery to make copies of themselves.

26 Apr 2024

Novel SYBR green-based RT-qPCRs developed for lone star virus detection

Announcing a new article publication for Zoonoses journal. Lone Star virus (LSV) is a newly characterized arbovirus with pathogenic potential.

26 Apr 2024

Did California's pediatric COVID-19 vaccination program reduce reported cases and hospitalizations?

Changes in the incidence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and related hospitalizations.

26 Apr 2024

New study offers promising targets for universal influenza B vaccine

In a milestone study led by the Peter Doherty Institute of Infection and Immunity (Doherty Institute), researchers have identified fragments from influenza B viruses that the immune system consistently recognize, offering promising targets for a universal influenza B vaccine

26 Apr 2024

Improving public health communication in African epidemics: Lessons learned and future directions

During epidemics of Ebola, COVID-19, Zika and other public health emergencies, effective communication of public health messages is crucial to control the spread of disease, maintain public trust, and encourage compliance with health measures.

25 Apr 2024

Personalized risk prediction tool helps prioritize high-risk infants for RSV prevention

A new tool to identify infants most at risk for severe respiratory syncytial virus (RSV) illness could aid pediatricians in prioritizing children under 1 to receive a preventive medication before RSV season (October-April), according to Vanderbilt University Medical Center (VUMC) research published in Open Forum Infectious Diseases and to be presented at the American Thoracic Society 2024 International Conference.

25 Apr 2024

Genetically modified mice reveal key players in immune defense against viruses

Chemokines are signaling proteins that orchestrate the interaction of immune cells against pathogens and tumors.

25 Apr 2024

MIT study reveals circadian impact on drug metabolism in engineered livers

Giving drugs at different times of day could significantly affect how they are metabolized in the liver, according to a new study from MIT.

25 Apr 2024

Putting genomic surveillance of pathogens at the forefront of future pandemic preparedness

The Covid-19 pandemic turned the world upside down. In fighting it, one of our most important weapons was genomic surveillance, based on whole genome sequencing, which collects all the genetic data of a given microorganism.

25 Apr 2024

Bivalent COVID-19 vaccine boosts immunity but needs to be updated

A major bivalent COVID-19 vaccine induces production of neutralizing antibodies against the coronavirus that circulated at the start of the pandemic as well as subvariants of omicron, albeit less abundantly, according to a Brazilian study reported in the Journal of Medical Virology.

25 Apr 2024