What is the shape and symmetry of the Influenza virus?

Spherical shape with helical symmetry.

Which glycoprotein antigen on the Influenza virus is responsible for hemagglutination?

Hemagglutinin (HA).

In which part of the cell does RNA replication of the Influenza virus occur?

In the nucleus.

How many segments does the RNA of the Influenza virus consist of?

Eight segments of negative sense single-stranded RNA.

Which subtype of Influenza A is most commonly associated with pandemics?

H1N1.

What is the incubation period for the Influenza virus?

18–72 hours.

Which method is the most sensitive for detecting Influenza virus?

Reverse transcriptase PCR (RT-PCR).

What are the two main types of antigenic variation seen in Influenza A?

Antigenic shift and antigenic drift.

What is a common complication of Influenza infection?

Bacterial pneumonia.

Which influenza vaccine type contains whole, inactivated viruses?

Whole Virus (WV) vaccine.

What are the α2–6 sialic acid receptors associated with?

Human strains of influenza.

What is a significant characteristic of the H5N1 avian flu strain?

It has a mortality rate greater than 60%.

Which parainfluenza virus type is most commonly associated with croup?

Types 1 and 2.

What is the primary mode of transmission for the mumps virus?

Respiratory droplets, saliva, and fomites.

What is the classical triad of congenital rubella syndrome?

Ear defects, ocular defects, and cardiac defects.

What is the most common complication of measles?

Otitis media and bronchopneumonia.

What type of vaccine is the measles vaccine?

Live attenuated vaccine.

What is the incubation period for rubella?

2–3 weeks (approximately 14 days).

What is the most common effect of the Rubella virus on infants?

Congenital rubella syndrome.

Which laboratory test is most specific for diagnosing measles?

Cytopathic effect showing multinucleated giant cells.

What is the preferred cell line for isolating Respiratory Syncytial Virus (RSV)?

HeLa and HEp-2 cell lines.

What is the main treatment for severe RSV infections in infants?

Ribavirin, usually given as an aerosol.

How does antigenic drift differ from antigenic shift in Influenza viruses?

Antigenic drift involves point mutations, while antigenic shift involves genetic reassortment.

What is the role of neuraminidase (NA) in Influenza virus pathogenesis?

It aids in virus release from infected cells and helps in elution from red blood cells.

What is the significance of the PB1F2 protein in avian flu strains?

It contributes to the high mortality rate of avian flu infections.

What is the primary reservoir for the mumps virus?

Humans only.

What is the common clinical manifestation of RSV in infants?

Bronchiolitis and pneumonia.

What type of vaccine is recommended for high-risk groups to prevent Influenza?

Inactivated influenza vaccine.

Which immune response is primarily stimulated by the live nasal spray influenza vaccine?

Both local and systemic immunity.

What is the primary clinical feature of measles during the incubation period?

Fever followed by Koplik's spots.