If I get a rabies vaccine, and am then accosted by a slobbering, foaming, rabid whatever, I still have to go get a rabies booster shot if I dont want to turn into a slobbering, foaming, rabid yam.
I feel like if I get a measles vaccine, and then go rub up against somebody who is all sick and measley, I can trust the vaccine already in me to do its job and protect me from getting measles.
Why is the rabies vaccine like this? I can understand needing a booster every couple of years, regardless of whether you have been bitten or not, but why cant they make the vaccine so it doesnt require the post-bite booster?
love
yams!!
There are some recent rabies threads, including one by a guy that was bitten by a rabid animal and had to get the treatment.
The Vaccine isn’t really a vaccine as you’re thinking of. Basically, it gives you higher resistance and is used by people who either work in a high risk environment or going somewhere high risk. For example, I had a rabies vaccine before going trekking in Tibet. I was warned by the doctor that if bitten by anything, I still needed to get my ass back and the full course started. Preferrably within one week, but certainly within two.
Right - I got a rabies vaccine under similar circumstances. My question is more along the lines of, if they can give you something that is good enough to give you more resistance, what is it about the virus, or about vaccine technology, that prevents it from being a straight up actual vaccine?
love
yams!!
The short answer is that it is insurance since the disease is nearly universally fatal and an adequate immune response nearly universally protective. If you had a well-documented complete and recent series, I would at least let you get by without adding Rabies Immune Globulin (although if it were me and it was a genuine bite by a rabid animal, I’d get the RIG as well, prior vaccination or not). The body’s ability to ramp up its anamnestic immune response is kick-started by the post-exposure vaccines. (The anamestic response is the memory response which occurs when an exposure triggers the immune system that has already been primed in the past.)
The WHO paper on Rabies http://www.who.int/wer/2007/wer8249_50.pdf is very readable and should answer many of the questions raised here. Yours in particular is down around page 432, I think.
For a disease which only has a prevalence in humans in the US of a couple of cases a year, I’m always amused how much interest there is in it. Those of us who have to address exposure on occasion normally err on the side of caution for obvious reasons.
You have to admit that it’s a bit of a poster-child as infectious diseases go, though. You get it from a bite, go raving mental, run around biting people, while drooling and barking and cowering in fear from glasses of water, and then you die in agony. It’s nearly as funky as all those african fevers that make you squirt jets of blood from your eye sockets before dissolving into a puddle of goop ten minutes after catching it. According to The Entertainment Industry, that is.
I can remember as a child there being practically one Rabies Movie ™ a month on TV.
Yep, what he said. Consider influenza. You are vaccinated. You are exposed at a later date. A certain percentage of exposed individuals will still become infected. Not a great situation if infection = death.
I have had a pre-exposure series, not really to protect me if I am bitten, since I will still pursue treatment in such a case. My pre-exposure series is designed to protect me in case of an exposure I am not aware of. For instance, an owner presents a neurologically abnormal pet. I am exposed to pet’s saliva and have an open wound. Owner takes pet home, it later dies, and it is lost to follow-up. Turns out it died of rabies without diagnosis.
Ah ha! So you are saying if the flu was as fatal as rabies, we would all be rushing off for post-exposure boosters every time we sat next to a sneezer on the subway. And the rabies vaccine is just as effective as the flu vaccine, but because it is fatal, you go in for boosters just to make sure.
I had thought it was something about the rabies virus in particular that made it impossible to create an effective vaccine - like there are things inherent in the shape of HIV that have thus far made it impossible to make a vaccine.
Chief Pedant, can I ask what is it that you do? Are you, by any chance, a virologist? (I am in school with the eventual goal of being a virologist.)
love
yams!!
IANAV(irologist), but it is my understanding that the influenza vaccine is not terrible effective (and efficacy varies year to year), while rabies vaccine is very effective. In fact, there has never been a case of rabies in a dog or cat that has received two vaccines in its lifetime!
ETA: This holiday season I have had the fortune to say, “Please pass the yams!!” on several occasions.
The Rabies vaccine is very effective. Post-exposure prophylaxis administered in a timely fashion is also pretty darn good. HIV is a problem because it just won’t sit still.
Influenza is quite a bit different than Rabies when it comes to effective immunization, btw, b/c it has many variants.
On the what-do-I-do front, I am only a lowly physician alas (Boards are in Internal Medicine and Emergency Medicine; most of my career was in the ED). We only apply what the really smart people like Virologists figure out. Thank goodness for them and best to you.
There’s no need for speculation about modern rabies vaccines. The rabies experts at the CDC review ALL the evidence periodically and, in consultation with the few rabies experts not at the CDC and under the auspices of the ACIP, make sound recommendations for the prevention of rabies.
The modern vaccines are good. I believe there remains only one case (Kenya, 1984 or so) of a person who died of rabies after receiving pre-exposure prophylaxis with a modern rabies vaccine. She had been vaccinated with HDCV during Peace Corps pre-service training while taking chloroquine and did NOT report her rabies exposure to her Peace Corps health care provider. It is believed that chloroquine blunted her response to the vaccine. It is assumed that (1) she would have lived WITHOUT post-exposure prophylaxis had she not received pre-exposure immunization and chloroquine simultaneously, (2) she would have lived had she received post exposure immunization (2 shots of vaccine) as recommended for everyone who has received pre-exposure immunization and is subsequently exposed.
I know of no evidence to suggest that there is any medical justification ever for giving rabies immune globulin to anyone who has completed the primary rabies pre-exposure immunizaiton series.
As has already been noted, when humans develop symptoms of rabies, the disease is almost universally and horribly fatal (extremely rare cases of survival have been reported). With the stakes that high, and seeing that no human vaccine has ever been found to offer 100% protection, it makes sense to offer followup prophylaxis to someone with documented exposure to a rabid animal.
It is my understanding that Rabies is one of the few diseases that allows for a post-infection shot, due to its long incubation period. The shot will induce an immune response against the virus in preparation for its outbreak. I think there’s one other disease you can do this with, but can’t think of it now.
