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. The word is from the Latin ''virus'' referring to poison and other noxious substances, first used in English in 1392. ''Virulent'', from Latin ''virulentus'' (poisonous), dates to 1400. A meaning of "agent that causes infectious disease" is first recorded in 1728, The term ''virion'' is also used to refer to a single infective viral particle. The plural is "viruses".

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?

Latest Virus News and Research

Better global health equality could prevent emergence of future SARS-CoV-2 variants of concern

In a new study, researchers used a simple phenomenological model to investigate the role of immunocompromised hosts in SARS-CoV-2 antigenic development.

17 Jan 2022

Study suggests vaccinated Omicron cases are unlikely to shed infectious virus 10 days after diagnosis or symptom onset

Researchers have been investigating the Omicron epidemic in Japan and have recently released an early report on the infectious period of the disease.

17 Jan 2022

Dexamethasone shown to upregulate innate and adaptive immune responses in COVID-19 acute respiratory distress syndrome patients

In a new study, researchers used per protocol bronchoalveolar lavage fluid (BALF) samples after intubation to evaluate the transcriptomic profiles of the local pulmonary host responses during early-stage severe coronavirus disease 2019 (COVID-19) acute respiratory distress syndrome (CARDS), non-COVID-19 ARDS, and sepsis.

17 Jan 2022

Study demonstrates that intra-host SARS-CoV-2 variants with reduced infectivity are developed during infection

A new paper discusses the appearance of quasi-species in a single host with prolonged infection, with different rates of infectivity and sensitivity to neutralization by antibodies elicited by the Pfizer vaccine or those present in convalescent plasma.

17 Jan 2022

Study investigates whether immune responses to BNT162b2 vaccine differ in subjects with and without prior SARS-CoV-2 infection

A new paper published in the journal JCI Insight reports on the differential levels of immunity achieved in those with and without a history of prior infection with the virus following one and two doses of the earliest vaccines to be approved for emergency use.

17 Jan 2022

Study identifies cellular receptors for alphaviruses shared across mosquitoes, humans, and animals

A new study led by researchers at Harvard Medical School has identified a set of cellular receptors for at least three related alphaviruses shared across mosquitoes, humans, and animals that host the virus.

17 Jan 2022

Pathogens turn off mitochondrial defense by hijacking a normal cellular response to stress

Mitochondria are known as energy suppliers for our cells, but they also play an important role in the defense against pathogens. They can initiate immune responses, and deprive pathogens of the nutrients they need to grow.

17 Jan 2022

Study analyzes the impact of global trust in government due to the COVID-19 pandemic

In a week when the UK Prime Minister Boris Johnson has admitted to breaking Covid-19 lockdown rules, a new study has found that impartial, transparent and truthful government communications are fundamental for achieving and maintaining government trust during public health emergencies.

17 Jan 2022

Mutations in SARS-CoV-2 Omicron variant promote cell binding

Researchers in Germany, based on their recent study published in the journal ChemBioChem, have proposed that the elevated occurrence of positively charged amino acids in specific domains of the severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) Omicron variant spike protein improves viral binding to cellular negatively charged receptors aiding in enhanced infectiousness.

16 Jan 2022

Monitoring rodents for SARS-CoV-2 and other coronaviruses, Hong Kong

A new study published in the Centers for Disease Control and Prevention’s Emerging Infectious Diseases journal has hypothesized that locations with positive SARS-CoV-2 in sewage could be used as potential surveillance targets to analyze if pestiferous urban rodents shed SARS-CoV-2 into the environment.

16 Jan 2022

Topical antiseptic Acriflavine inhibits SARS-CoV-2 and other betacoronaviruses

A new study, published in the journal Cell Chemical Biology, has reported the discovery of acriflavine (ACF), an effective inhibitor of SARS-CoV-2. This drug is a mixture of trypaflavines (3,6-diamino-10-methylacridinium chloride and 3,6-diamino-3-methylacridinium chloride) and proflavine (3,6-diaminoacridine).

16 Jan 2022

Genome editing in vascular endothelial cells made possible with a powerful new delivery system

Northwestern Medicine scientists developed a unique nanoparticle to deliver genome editing technology, including CRISPR/Cas9, to endothelial cells, which line blood vessel walls.

16 Jan 2022

Cannabidiol may improve innate immune response against SARS-CoV-2

A recent study shows evidence that cannabidiol, an important active ingredient in the Cannabis sativa plant, can augment the antiviral innate immune response and prophylactically prime the innate antiviral response of cells – enabling in turn improved response against viruses such as the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

16 Jan 2022

Rapid antigen test for SARS-CoV-2 proves to be highly accurate for pediatric populations

In a large prospective study of just over 1,000 patients ages 17 and younger who were seen at the Baltimore Convention Center Field Hospital (BCCFH) testing site during a seven-month period last year, researchers from Johns Hopkins Medicine and collaborating institutions report that a rapid antigen test for SARS-CoV-2 — the virus that causes COVID-19 — proved highly accurate when compared to the established standard virus detection method: the polymerase chain reaction (PCR).

16 Jan 2022

UK donates COVID-19 vaccines to Uganda to help tackle the pandemic

Five million of these doses are being offered to the COVAX Facility to ensure equitable, global access to COVID-19 vaccines.

16 Jan 2022

UV-C light prevents airborne transmission of SARS-CoV-2

Researchers demonstrate that ultraviolet light-C (UV-C) effectively prevents airborne transmission of SARS-CoV-2.

16 Jan 2022

SARS-CoV-2 Omicron has similar infectious viral load to Delta

Researchers compare SARS-CoV-2 pre-variants of concern strains to the Delta and Omicron VOCs.

16 Jan 2022

With no end in sight to pandemic life, parents find disruption is the new normal

As my kindergartner fumbled with his shoes, I stood at our door sifting through the mental parenting checklist newly lodged in my brain: backpack. Sweatshirt. Snacks. Sunscreen. Water bottle. KN95 mask. Vaccination card.

15 Jan 2022

As omicron surges, effort to vaccinate young children stalls

Two months after Pfizer's covid vaccine was authorized for children ages 5 to 11, just 27% have received at least one shot, according to Jan. 12 data from the Centers for Disease Control and Prevention. Only 18%, or 5 million kids, have both doses.

15 Jan 2022

Exploring the relationship between stem cells and COVID-19

Though COVID-19-related stem cell clinical research is still in its infancy, stem cell treatment offers extensive clinical application possibilities and a far-reaching relevance thanks to ongoing exploration of stem cell clinical research and data mining.

14 Jan 2022