Please tell me if I got something wrong about virology

Question

Note: Apologies for any grammatical errors.

I have been working on a story of mine for quite a while now. A part of that story is a viral pathogen that turns people infected with it into what is basically analogous to 'fast zombies'

The following is a quick rundown of the details I have come up with:

1. Types of immunity:

A) Cannot be infected through inhalation of virus aerosols. Can only be infected by getting bitten or spat in the face (high virus concentration; entering through mucous membranes). Will be referred to as Group A or Alpha for simplicity's sake from now on.

B) Can be infected through inhalation of virus aerosols as well as the other vectors mentioned above. Will be referred to as Group B or Beta for simplicity's sake from now on.

2. Modes of Transmission:

When the virus is introduced into the body through a bite from an infected, it travels from the site of the bite to the brain by moving within the nervous system. As mentioned, exposure can also occur through inhalation of aerosolized virus at high concentrations through mucous membranes (Group B). As the virus is not bloodborne, it cannot be transmitted via blood spatter.

3. Stages of infection:

Airborne infection:

1. Subject is infected.
2. After virus has moved past mucosal epithelial barriers, it establishes infection in oropharyngeal or small bowel lymphoid tissues. Virus then travels through the body until it reaches the brain. This process can last approximately 1 to 2 weeks. During this period the subjects has no outwardly noticeable symptoms. However, infection of other Beta subjects is already possible.```
3. Subject can develop a cough associated with a sore throat. Headaches can also manifest during this time. Subject also becomes irritable during this time.
4. Subject starts to present further noticeable symptoms. Symptoms can include: Unusually heavy discharge of nasal mucus fluid; red, irritated, and bloodshot eyes.
5. Overproduction of saliva from salivary glands (Week 2 - 3)
6. Subject begins to show extreme aggression toward uninfected persons

Infection through bite:

1. Virus is introduced into the body through a bite from an infected,
2. Virus travels from the site of the bite to the brain by moving within the nervous system
3. Stages 3 - 6 are largely the same, with the biggest difference being shorter incubation period

Overall average incubation period from infection to to full onset of the disease:

• Airborne: 3 - 4 Weeks:
• Bitten: 6 - 20 Days

Answer 1

Para-Rabies:

It is rare to have a virus have significantly different modes of transmission based on host immunity (not impossible). If the virus transmits through a bite, it's likely bloodborne as well. The more things you ask a virus (very simple thing) to do, the less plausible. Bacteria can exhibit more complex behaviors, but you clearly want a virus. I'd research rabies, make your virus a variant of the rabies virus (does much of what you want, has established patterns, neurological, transmissible via bite, causes behavioral abnormality.

To get the combination of infective pathways you want, consider using two related viruses. So as a scenario, imagine someone makes a super-rabies virus in a lab for terror purposes. Outbreaks would be horrifying but not globally disastrous. But sloppy work means the virus merges with an influenza strain in a coinfected individual and a hybrid virus emerges that is slow-incubating, looks like the flu for most of its early infection pattern, and doesn't affect anyone who had that strain of the flu previously. Developing a vaccine is only partly effective (and if no one ever made a vaccine against this flu strain prior, it could take a long time to do so).One is transmitted airborne, but a substantial percent of the populous is immune.

The other is transmitted via bite, but the zombies extensively bite each other to the point that coinfection with the two virus strains is widely prevalent. A gentle breaking of the skin could even be the socializing element that ties your zombies together. If zombies accept biting from other zombies, and look for the presence of bite marks and aggressive biting behavior as the indicator of who is or isn't a zombie, you have a way the zombies know who is or isn't to be attacked. The bites physically mark them to each other (and the more a person is bit up, the faster the infection). A person who was "captured" by zombies would get repeatedly bitten (increasing the chance of the bite-transmissible strain being spread) and the zombies would keep biting until the person started biting back. The constant in-biting makes "faking it" by covering yourself in false bites possible but extremely risky behavior. The fact that not all zombies are guaranteed to have the bite-transmissible form also means people can get bitten and still convince themselves they might not be infected, increasing the likelihood they might hide the fact they were bitten to avoid being killed/locked up/ostracized.

Answer 2

Most of it is ok

Most of what you are saying is ok.

Viruses are mostly highly specific where they grow. Most often only a few cells with a certain type of DNA will be able to be affected. That means sickness can have difficulties to spread to many different species. You don't have to be afraid of most dog diseases thanks to this, although there are exceptions like rabies.

Infecting multiple cells can help with spreading through the body. Growing first in the belly before going to the brain. Though it can make more sense for the airborne virus to start in the lungs. That way it'll be easier to develop the cough and have large enough concentrations of viruses to infect others thanks to the cough. It also explains the further development of cold like symptoms. Growing in the gut is highly unlikely to give the effects you want. Outward noticeable symptoms often develop thanks to the body as it responds to the sickness and not the virus itself, so you're clear there as well.

The other category can house itself in other tissue to not become airborne, or have a defect that they near instantly die if expelled from the body.

If I remember correctly, viruses (and bacteria) can have multistage behaviour. First they simply grow and spread a little throughout the body. Then, if the concentration is high enough, some hormonal triggers can make them change their behaviour and spread aggressively. Then they can primarily focus on the brain for both reproduction, but also control. Viruses like rabies already try to control you in some ways, like making you avoid water. The virus can do the same. The reasons can be multiple why it does this, but self preservation, resource gathering or ability to spread more efficiently are all good reasons.

Travelling through the nervous system doesn't make sense however. It would generally be slow, as viruses have little in transport capabilities themselves. So why not use the blood (+ lymph nodes)? It is used by most viruses to get around, incredibly fast and spreads to literally everywhere in the body. The brain will be difficult thanks to the blood brain barrier, but as this is weakest at the olfactory bulb (smell) they always have an in (likely a reason you lose/change smell during Corona!). During the second stage they might also release things that can weaken this barrier throughout the brain, or move through the few other transport systems after infecting the olfactory bulb.

Other methods of infection can help greatly with the spread of the virus. That way it can shorten incubation times and such.