Animal Health Matters: Sticking yourself with a vaccine needle – what could happen?

Russ Daly
Special to the Farm Forum

Being an Extension veterinarian with public health duties, there’s one type of question that I get asked quite regularly. I received a prime example via email a few weeks ago:

“A friend of mine was vaccinating calves and accidentally poked himself with (XYZ) vaccine. Should he be worried?”

If you raise livestock, chances are good you’ve had this happen yourself. Some studies indicate that upwards of 80% of livestock producers have experienced a needle stick while vaccinating or treating animals. Despite our best attempts to restrain our patients, sometimes they jump, jerk, or get downright crazy at the exact split second when our syringe needle is in just the wrong place relative to one of our body parts.

I remember well the first time I’d done this to myself. I was vaccinating calves with a 7-way Clostridial vaccine, when I managed to drive the needle directly into the back of my non-syringe-bearing hand. I actually didn’t give it a second thought when it happened – I was good at shaking off all the minor mishaps that occur during the course of a chute job. But by the time I was cleaning up after the job, that hand was throbbing, swollen, and getting sorer by the minute. I was trying to remember whether I’d smashed it in the chute, it hurt so bad.

My body’s reaction exemplifies why people get concerned following such accidents – the swelling and pain seem out of proportion to the actual needle poke. This is due mostly to our body’s response to the adjuvant in the vaccine. Adjuvants are the substances that make vaccines look milky and thick. Formulated out of oil emulsions and other chemicals, they’re added to vaccines to get the attention of the vaccinated animal’s immune system, improving the response. During the vaccine approval process, adjuvants are tested to make sure they’re safe and don’t create too painful of a reaction in the species they’re going into.

Our regular human vaccines like flu and tetanus are formulated to be relatively smooth, reaction-wise. Adjuvants in animal vaccines are quite different; thus the relatively severe reaction that happens when we poke ourselves. Additionally, some cattle antigens (the part of the vaccine that mimics the pathogen we’re vaccinating against) are different enough to us that our body reacts to them in an over-exuberant way.

What we usually don’t have to worry about with these inadvertent vaccine exposures is getting the disease the vaccine is meant to protect against! The germs comprising these vaccines are either completely inactivated (killed vaccines) or weakened (modified live vaccines) such that they can’t reproduce and cause illness in people (or the animals themselves, for that matter). That seems to be a common worry among the healthcare providers I’ve encountered in these cases – they’re worried we’re going to contract some horrible animal disease.

While I wasn’t going to catch blackleg from my 7-way needle poke, there are some livestock vaccines that can cause serious problems if we stick ourselves with them. Brucellosis (Bangs) vaccine is a live bacterial vaccine (only administered by vets, however) that can give us actual Brucellosis. And some non-vaccine animal health products can mean severe consequences if accidentally injected into a person: the antibiotic Micotil and reproductive hormones (pregnant women) come to mind.

Another common problem with accidental animal vaccine needle sticks is infection. Livestock environments by nature are contaminated with dirt and manure. Accidentally introducing some of that stuff under a person’s skin can create some nasty infections. Even worse would be when the needle stick is deep or enters one of your joints.

When it happens, clean up the site and let it bleed in order for any injected material to seep out. If swelling and pain set in, use ice and pain reliever. If things aren’t getting better, or get better but then worsen, call your health care provider and have information about the product you used ready. And my goodness, I hope this discussion dissuades anyone from thinking it’s a good idea to deliberately give themselves an animal vaccine!

Of course, prevention is always the best practice. Take time to restrain animals well when you’re working them. Keep the environment as clean as possible – and don’t be afraid to slow down a bit and pay attention to where that needle is headed next!