What is a variant flu virus?

When flu viruses that normally affect pigs (swine flu viruses) cause infections in humans, these viruses are called variant influenza viruses. One example of a variant flu virus is H3N2v. Sometimes, human infections with novel or variant flu viruses occur because of the close contact between humans and animals.

Is swine flu a variant of the flu?

H1N1 is a type of influenza A virus, and H1N1 is one of several flu virus strains that can cause the seasonal flu. Symptoms of the H1N1 flu are the same as those of the seasonal flu.

How many strains of H1N1 are there?

There are 18 different hemagglutinin subtypes and 11 different neuraminidase subtypes (H1 through H18 and N1 through N11, respectively).

What causes flu variants?

New influenza strains of influenza virus arise continually as a result of two mechanisms that alter the genetic code in the viral RNA. These mechansims are referred to as genetic drift and genetic shift. Genetic Shifts result from reassortment of genetic material between vastly different strains of influenza viruses.

What are viral variants?

What are viral variants? When a virus enters the body, it invades human cells and replicates (makes more copies of itself). When a virus makes copies of itself, it sometimes changes a bit. These changes are called mutations. A virus that has mutated is referred to as a variant.

Is H1N1 Type A or B?

Flu (influenza) viruses are divided into four broad categories: influenza A, B, C or D. Influenza A is the most common type. H1N1 flu is a subtype of influenza A. Subtypes of influenza A are categorized based on two proteins on the surface of the virus, hemagglutinin (H) and neuraminidase (N).

What are the symptoms of Type A flu?

If you have influenza A, you will have some or all of these symptoms:

fever and chills.
headache and muscle aches.
feeling tired and weak.
sneezing, and stuffy or runny nose.
sore throat and cough.

How do flu strains start?

What causes Covid variants?

Variants of viruses occur when there is a change — or mutation — to the virus’s genes. Ray says it is the nature of RNA viruses such as the coronavirus to evolve and change gradually. “Geographic separation tends to result in genetically distinct variants,” he says.