Can Older Strains Of The Flu Reemerge?

[Jimmy]

Flu viruses mutate every year, but can earlier strains reappear or are they done for good?

 

[Heyo]

Flu viruses mutate every year, but can earlier strains reappear or are they done for good?

Since mutations are random, there could be a repeat of an older strain, but it is unlikely. The older strains went away because the population they infected is now immune.
The flu virus is also unlikely to "hide" as it normally can't survive a long time outside a host. But there can be special conditions like in a frozen body where they might survive, but that's also unlikely and never happened with the flu.

 

[GoodAttention]

Flu viruses mutate every year, but can earlier strains reappear or are they done for good?

Not relating to mutations specifically, however if

(1) Viruses and other infectious diseases do survive in permafrost
(2) Climate change is real
(3) Permafrost thawing is real

There is a chance humans will be exposed to earlier strains of viruses that our immune systems have "forgotten".

 

[shunyadragon]

A word of caution mutations are not truly random. They follow patterns of mutation over time based on their survival. As the hosts develop immunity the viruses mutate to adjust to degree of immunity. Older versions are very unlikely, but similar versions can be in the future.

The purpose of all viruses is to survive and they mutate to survive. Different viruses have different genetic strategies. More to follow. ..

 

[Jimmy]

A word of caution mutations are not truly random. They follow patterns of mutation over time based on their survival. As the hosts develop immunity the viruses mutate to adjust to degree of immunity. Older versions are very unlikely, but similar versions can be in the future.

The purpose of all viruses is to survive and they mutate to survive. Different viruses have different genetic strategies. More to follow. ..

So if it’s a similar version would a past vaccination help to fight it?

 

[shunyadragon]

So if it’s a similar version would a past vaccination help to fight it?

Maybe, In terms of COVID vaccines. The earlier vaccines were very successful, but as time goes on the effectiveness of the vaccines to prevent infection deteriorated. Though they tend to reduce the severity, maybe, but the COVID viruses are genetically smart, and may just become endemic to humans and continue to infect us in milder versions. The goal of all viruses is to survive living on the hosts not necessarily to kill the host, The trend in COVID viruses is the newest best virus tends to replace older viruses in the population. There may be a pandemic verion in the future, and I hope we are prepared to deal with it,

For Flu viruses every year they are seasonal jumping from one species to another, and appear as several different versions of the virus in the populations. Yes, there is a potential of a Flu pandemic version, but I believe it will be easier to deal with then COVID, but maybe not.

 

[Heyo]

viruses are genetically smart

The goal of all viruses is to survive living on the hosts not necessarily to kill the host

Just to clarify for those who don't understand figurative speech: there is no intelligence in viruses, and there isn't a goal either. We see a pattern and attribute agency - or talk as if there was agency - but there really isn't. It's just a function of how evolution works.

 

[shunyadragon]

Just to clarify for those who don't understand figurative speech: there is no intelligence in viruses, and there isn't a goal either. We see a pattern and attribute agency - or talk as if there was agency - but there really isn't. It's just a function of how evolution works.

True

 

[shunyadragon]

Just to clarify for those who don't understand figurative speech: there is no intelligence in viruses, and there isn't a goal either. We see a pattern and attribute agency - or talk as if there was agency - but there really isn't. It's just a function of how evolution works.

It is a bit more than just figurative speech. It is more than just a random mutations.

Determinants of Virus Variation, Evolution, and Host Adaptation

Virus evolution is the change in the genetic structure of a viral population over time and results in the emergence of new viral variants, strains, and species with novel biological properties, including adaptation to new hosts. There are host, vector, ...

www.ncbi.nlm.nih.gov

Virus evolution is the change in the genetic structure of a viral population over time and results in the emergence of new viral variants, strains, and species with novel biological properties, including adaptation to new hosts. There are host, vector, environmental, and viral factors that contribute to virus evolution. To achieve or fine tune compatibility and successfully establish infection, viruses adapt to a particular host species or to a group of species. However, some viruses are better able to adapt to diverse hosts, vectors, and environments. Viruses generate genetic diversity through mutation, reassortment, and recombination. Plant viruses are exposed to genetic drift and selection pressures by host and vector factors, and random variants or those with a competitive advantage are fixed in the population and mediate the emergence of new viral strains or species with novel biological properties. This process creates a footprint in the virus genome evident as the preferential accumulation of substitutions, insertions, or deletions in areas of the genome that function as determinants of host adaptation. Here, with respect to plant viruses, we review the current understanding of the sources of variation, the effect of selection, and its role in virus evolution and host adaptation.