Many mutations in the gene that codes for the spike protein allowed the virus to more effectively infect lung cells by interacting with both the ACE2 receptor & the TMPRSS2 protease

T cell-based immunity gained against other COVID-19 variants did not provide any protection against the Omicron variant

T and B cell-based immunity gained against other COVID-19 variants did not provide any protection against the Omicron variant

Many mutations in the gene that codes for the spike protein allowed the virus to more effectively infect lung cells by interacting with the ACE2 receptor but NOT the TMPRSS2 protease

Attachment

Release

Replication & protein synthesis

Viral assembly

SARS-CoV-2 spike protein contains a polybasic cleavage site

SARS involved asymptomatic transmission

SARS-CoV-2 infection can be treated effectively with hydroxychloroquine

Only SARS-CoV-2 uses ACE2 as an attachment receptor

Severe cases of COVID-19 display overactivation of inflammatory response markers leading to lung damage

Moderate COVID-19 cases display downregulation of interferon proteins preventing lung damage 

Severe cases of COVID-19 display downregulation of interferon proteins leading to lung damage 

Downregulation of interferons is a key response of cells to viral infection 

There have been cases of transmission from bird to humans of bird flu viruses

Some bird flu viruses are extremely pathogenic

There

have been cases of transmission of human to human of bird flu viruses

Some bird flu viruses have low pathogenicity

The H1N1 virus led to a rapid innate and adaptive immune responses, which meant only a portion of the population showed symptoms related to the infection

The degree of genetic similarity between the H1N1 swine flu virus & other influenza strains

The degree of genetic similarity between the H1N1 swine flu virus & other swine flu viruses

The H1N1 virus led to a rapid adaptive immune response, which meant only a portion of the population showed symptoms related to the infection

HA must form a trimer, where each subunit can bind to a sialic acid, before it undergoes a conformational change to promote membrane fusion between the virus and lung cell

HA must form a trimer, where the subunits work together to bind to one sialic acid, before it undergoes a conformational change to create a protein channel through which the viral genetic material can enter the lung cell

HA must form a trimer, where each subunit can bind to a sialic acid, before it undergoes a conformational change to create a protein channel through which the viral genetic material can enter the lung cell

HA must form a trimer, where the subunits work together to bind to one sialic acid, before it undergoes a conformational change to promote membrane fusion between the virus and lung cell

Internal proteins within the virus continue to change due to antigenic drift

Most years the flu virus changes so much that existing immunity against the flu virus won’t provide any immunity against the new versions of the virus

Proteins on the surface of the virus continue to change due to antigenic drift

Each year the flu virus changes so much that existing immunity against the flu virus won’t provide any immunity against the new versions of the virus