Rabies... Vaccines & Post-Exposure Treatment

[TN_Farmer]

I read some posts about rabies here on AH, and there was some less than accurate information being shared. So I thought I would clarify the current prevention and treatment of rabies here.

Here are my street creds: I dabble in a lot of things, but primarily I am an emergency medicine physician with a fellowship in wilderness medicine. I am a prior military physician who has lived and travelled overseas around the world. I deal with rabies prevention and post-exposure treatment on a regular basis.

There are three aspects of rabies in humans we need to consider:

1. Active Rabies
2. Post-Exposure Prophylaxis
3. Rabies Prevention

1. ACTIVE RABIES
Once you have symptoms of rabies, you are pretty much out of luck. It is basically 100% fatal. We have a protocol to try and save an infected person's life, but it has a VERY low survival rate. Bottom line: you don't want rabies. Fortunately, getting rabies is not very common, but hunting overseas puts you in a higher-risk category than someone who doesn’t travel or doesn’t hunt.

2. POST-EXPOSURE PROPHYLAXIS
If you are exposed to an animal with rabies or exposed to an animal that MIGHT have rabies, then we initiate the Post-Exposure Rabies Prophylaxis treatment protocol.
Ideally, this is started as soon as possible after exposure (less than 24 hours is ideal, but under 72 hours is best).

Post-Exposure Rabies Prophylaxis treatment protocol has 2 parts:
A. Rabies Vaccine
B. Rabies Immunoglobulin (RIG)

A. The Post Exposure Rabies Vaccine series is a FOUR shot series given on day 0, day 3, day 7, and day 14.
This is given in the deltoid muscle. It used to be given in the abdominal wall muscles. We don't do that anymore.
This is given as soon as possible after exposure.
This is not very expensive (compared to RIG) in the U.S. averaging $50-$100 per shot.
This is used to build a very rapid immunity to rabies.
If used ALONE, this MAY stop a rabies infection even if you are bitten by a rabies-infected animal.
It is not 100% effective in preventing an infection though which is why they developed RIG

B. The Rabies Immunoglobulin (RIG) binds any circulating rabies virus, so that it cannot infect the person.
It is given as soon as possible after exposure.
It is typically injected at the site of exposure (like a bite or wound).
It is weight based, so the larger the person, the higher the dose. If the wound is smaller than can accept the full dosing of medicine (like on a finger tip), then the rest of the medicine is given in the deltoid or gluteus muscles.
RIG is VERY expensive in the US (ranging from $3,500-$25,00!)

When both Rabies Vaccine and Rabies Immunoglobulin (RIG) are used together, it is VERY effective in preventing rabies in people even if they are severely bitten by a rabies-infected animal.

3. RABIES PREVENTION (AKA PRE-EXPOSURE PROPHYLAXIS)
Rabies prevention is attained with TWO shots of the Rabies Vaccine.
Given on day 0 and day 7.
Rabies vaccines last a few years (yes, this is vague, because immunity duration is different in everyone). If you want to be really sure, you can test titers, or you can just get a booster at 1 year and then every 2-3 years.

DO I NEED A RABIES VACCINE?
Definitely, talk to your physician about this, ideally one with overseas travel experience.
The CDC has country specific recommendations for rabies pre-exposure vaccination.
https://wwwnc.cdc.gov/travel/destinations/list

Generally speaking, if you are traveling to a country with rabies AND you are “performing occupational or recreational activities that increase risk for exposure to potentially rabid animals” AND you “might have difficulty getting prompt access to safe post-exposure prophylaxis”, then it is recommended that you get the Rabies Pre-Exposure Prophylaxis vaccinations.

My take: Many places we hunt overseas are going to have rabies and we are going to be exposed to animals and we are going to be fairly remote. I would strongly consider getting the vaccines, but everyone gets to make their own choices.

Happy hunting!

 

[BryceM]

Great info. Thanks, from one doc to another.

 

[375Fox]

Is there a reason rabies vaccine for people isn’t more commonly recommended in US? How frequent are negative reactions?

 

[TN_Farmer]

Is there a reason rabies vaccine for people isn’t more commonly recommended in US? How frequent are negative reactions?

Rabies in the U.S. is very rare.
Currently only about 10 people die from rabies in the U.S. each year (population of 335 million)
In the early 1900's, over 100 people died from rabies per year in the U.S. (population of 76 million)

Compared to somewhere like Zimbabwe that has over 400 people dying from rabies each year (population of 16 million).

Or India (not currently allowing recreational hunting) with 18,000-20,000 rabies deaths per year (population of 1.4 billion).

Reactions to rabies vaccine is actually quite high compared to other vaccines; however, the vast majority of reaction are very mild. Severe side effects from rabies vaccines are exceedingly rare.

 

[Opposite Pole]

I’m preventatively vaccinated against rabies. Rabies is not widespread in Europe but occasional outbreaks do occur, often in foxes. I figured if I shot and handled an infected animal that did not yet display any obvious signs of illness and had something like a cut on my hand I could unknowingly expose myself to infection in which case I would not find out about it until it was too late. The two shots cost me roughly €80, I figured it was a good investment. This is very individual but I’ve never had any negative reactions to a vaccine including the rabies one.

I’m not sure about other European countries but in Poland, we have an active wild animal vaccination program in the form of aerial drops of baits containing the vaccine targeting foxes.

 

[Philip Glass]

Thank you for your expertise in this matter and the excellent explanation.
Being a rancher, hunter, & trapper I had the rabies vaccine a few years back. My brother, like you, is an ER physician and he told me that the titers had to be checked on occasion. I should do that.
From my experience most safaris don't have much risk in terms of rabies. As clients we don't do the skinning and handling like we would here at home.

 

[V.Veritas]

Thank you. I appreciate your detailed explanation of the rabies protocol.

To be perfectly honest, I'm still struggling comprehending item 2.A from an "engineering" perspective. Why the human body doesn't trigger immediately the immune response to the initial exposure to the virus and needs to be artificially exposed through vaccination (as a treatment)?

The second paragraph it makes sense to me though. Once the imune response it's triggered (naturally or artificially) it may or may not be sufficient to fight the infection of the rabis depending on the host health condition, hence the RIG is necessary to eliminate this unknown factor.

Great topic! Thanks.

 

[Pilgrim]

So what if it's been more than 72 hours? At what point are you doomed?

 

[CJW]

Reminds me of this recent story. It can happen.

https://www.cbc.ca/news/canada/hamilton/rabies-death-1.7341335

 

[meigsbucks]

Does the vaccine have an increased risk of Guillan Barre’ Syndrome? The reason I ask is that I had GBS and have been directed to watch what vaccines I receive.

 

[DieJager]

Planned a trip a few years ago to Eastern Europe but the war screwed things up. Part of the planning was getting our family up to date with the necessary travel vaccines. We all got the rabies shot. If getting bitten by a rabies infected animal we only need a few shots what I understood. And not the antidote that is harder to get in a lot of countries.

Also as a hunter getting in contact now and then with foxes it seemed a good choice to get the vaccine.

 

[TSIBINDI]

...Back in the day (1945) I was bitten by a rabid dog. The dog was quickly apprehended and killed. Subsequent test proved the animal was infected with rabies. Within 36hrs I was beginning the treatment. Fifteen days and fifteen injections in the stomach. I can vividly remember the incident, and the treatment. Not fun for a seven-year-old.

 

[TN_Farmer]

Thank you. I appreciate your detailed explanation of the rabies protocol.

To be perfectly honest, I'm still struggling comprehending item 2.A from an "engineering" perspective. Why the human body doesn't trigger immediately the immune response to the initial exposure to the virus and needs to be artificially exposed through vaccination (as a treatment)?

The second paragraph it makes sense to me though. Once the imune response it's triggered (naturally or artificially) it may or may not be sufficient to fight the infection of the rabis depending on the host health condition, hence the RIG is necessary to eliminate this unknown factor.

Great topic! Thanks.

Our immune system's pace of creating natural immunity is not super fast.
But our bodies have to go through the infection first before they develop antibodies.
This is true with every infection we get.
If we developed antibodies before the infection caused symptoms, then we would never get sick.

The problem with rabies (and other severe diseases such as ebola, plague, etc) is that the infection often kills the host before it can create the antibodies to fight off the infection.

With rabies specifically, fortunately, it is a relatively slow progressing infection, so the vaccine alone can sometimes allow the body to create antibodies to fight the infection before it is established enough to kill the host.

But this is the benefit of the rabies immunoglobulin (RIG). This will bind most (if not all) of the active virus in the host, and then the vaccine-induced antibodies cleans up the rest.

 

[TN_Farmer]

So what if it's been more than 72 hours? At what point are you doomed?

No necessarily. In fact, usually not.
Rabies is a fairly slow progressing infection... it takes a while to get established in the host.

If you have a very small amount of rabies exposure... a tiny cut to a finger, for example... it may take a week or quite a bit longer for the infection to get established. We are not exactly sure where the timeline cutoff lies, because every person and infection is a little different.

If you have a large exposure (large bite wounds) or a more proximal exposure (on the face or neck), then the timeline is likely shortened quite a bit.

This is why the recommendation is to start treatment as soon as possible after exposure... up to the point where the patient shows evidence of infection/has symptoms.

Once the host is symptomatic, it is too late.

 

[Lumaberpat]

Those glutinous Maximus shots are painful, I was glad they weren’t in the belly though!

I shot a rabid raccoon and got covered in blood when the dogs tore it apart so I got option 3.

 

[TN_Farmer]

Does the vaccine have an increased risk of Guillan Barre’ Syndrome? The reason I ask is that I had GBS and have been directed to watch what vaccines I receive.

All vaccines have a risk of GBS. Unfortunately, it's the nature of vaccines.
Some vaccines have higher risk and some have lower risk.

Generally speaking, the modern versions of the rabies vaccines have relatively low risk of GBS (1/32,000). Older versions of the rabies vaccine definitely had a higher risk (1/1,600).

This is not really the place for specific medical advice, but generally, if you've had GBS in the past, you are likely at a higher risk of getting it again. Definitely talk to your physician about any and all vaccines before you get them.

 

[Osama Mahdi]

Any bite from any animal ( carnivorous or herbivores)or bat must consider a potential threat and having rabies.
If the animal still a live and with no symptoms after 10 days of the bite date then the animal was without rabies at the time of bite.
I took 3 vaccine shot (Franch made) as a preventing measures when I worked with rabies virus in a laboratory years ago.

When I shot a baboon, my PH made me open his mouth for a picture. I cleaned my hands with alcohol disinfectant that I always carry, not from rabies but from monkey herpes virus ( cause brain infection in human %90 death rate).Excellent information, every hunter should know about it...
Many thanks

 

[Oldwavy]

Those glutinous maximus injections hurt.

 

[Pilgrim]

When is it considered exposure for rabies? My understanding is that blood contact doesn't expose you to rabies, it's all in the saliva.

 

[Dewald]

When is it considered exposure for rabies? My understanding is that blood contact doesn't expose you to rabies, it's all in the saliva.

Not to interfere with a fellow doc’s excellent and informative thread, but I can share with you the protocol we use.

Category 1 exposure is contact with an infected animal, saliva exposure to in tact skin. This carries minimum risk for transmission and is regarded by some as not an exposure.

Category 2 exposure is minor skin trauma from bites or scratches, involving saliva from the animal, but with no visible bleeding. This exposure carries a risk for transmission, although still low. Obviously these things are impossible to quantify in terms of percentage or absolute values.

Category 3 exposure is when skin is breached, with associated bleeding and subsequent saliva contact or contact of saliva on mucosal surfaces. This is regarded as a high risk exposure and will receive immunoglobulin in the wound sites as well as the four vaccines.

Contact with all other bodily fluids, except saliva and cerebrospinal fluid, from an infected animal is believed to not carry any exposure risk and seen as a Category 1 exposure.