Respiratory viruses 2

Coronaviruses

A large family of viruses that can cause diseases in animals and humans, including respiratory infections. They are characterized by their crown-like shape when viewed under an electron microscope and can lead to illnesses ranging from the common cold to more severe diseases like COVID-19 and MERS. There are several types of coronaviruses that can affect humans, including SARS-CoV-2, which is known for causing the COVID-19 pandemic. Coronaviruses have a positive-sense single-stranded RNA genome and can mutate rapidly, which presents challenges for vaccine development and herd immunity. They primarily spread through respiratory droplets released when an infected person coughs, sneezes, or talks, and can also survive on surfaces for varying amounts of time, contributing to their transmission.

Zoonotic spill-over

The process by which a virus jumps from one species to another, often from animals to humans.

SARS-CoV-2

The virus responsible for the COVID-19 pandemic, part of the beta coronavirus family.

Phylogeny

The evolutionary history and relationships among species, often shown in a branching diagram.

Epithelial cells

Cells that line the surfaces of organs and structures throughout the body, commonly infected by coronaviruses.

Cytokine storm

An overreaction of the immune system, leading to excessive inflammation and damage to tissues.

Spike protein

A key protein on the surface of the coronavirus that allows it to enter human cells, targeted by vaccines.

Antigenic shift

A major change in a virus that results in new hemagglutinin or neuraminidase proteins, often caused by reassortment.

Segmented RNA virus

A virus with a genome divided into separate segments, as seen in influenza viruses.

Coronaviruses

A large family of viruses that can cause diseases in animals and humans, including respiratory infections. They are characterized by their crown-like shape when viewed under an electron microscope and can lead to illnesses ranging from the common cold to more severe diseases like COVID-19 and MERS. There are several types of coronaviruses that can affect humans, including SARS-CoV-2, which is known for causing the COVID-19 pandemic.

RNA-dependent RNA polymerase

An enzyme used by RNA viruses to replicate their genetic material; lacks proofreading ability, leading to mutations.

Common cold coronaviruses

Coronaviruses that cause mild respiratory infections, including 229E, OC43, NL63, and HKU1.

MERS

Middle East Respiratory Syndrome, caused by a coronavirus primarily transmitted from camels to humans.

H1N1

A subtype of the influenza A virus known for causing the 1918 flu pandemic.

TMPRSS2

A protein that acts as a coreceptor for SARS-CoV-2, aiding its entry into human cells.

Viral replication cycle

The process by which a virus enters a host cell, replicates, and assembles new viral particles.

Antigenic drift

Minor changes in viral proteins due to mutations, allowing viruses to evade the immune response.