The FIV Vaccine: What You Need to Know
(This post is Part 2 of our FIV series. If you missed Part 1, The Ins & Outs of FIV, we recommend that you read that post first, as it will give you a better understanding of what FIV is.)
The topic of vaccinations is a controversial one these days – to vaccinate or not to vaccinate? There are so many arguments for and against, it is difficult to know what the best option is. As with just about everything, the option that is best for one may not be the best for another. It is important to be as informed as possible, and, with the help of a veterinarian, make the decision that is best for you and your cat. The case is no different with the FIV vaccine.
The FIV vaccine was developed in 2002. It was at first praised as being 85% effective against FIV infection, but as more information about the vaccine came out, enthusiasm for it began to dwindle. There are a few issues with the vaccine that lead many to agree that it is not a suitable preventative option. In fact, there are veterinarians who will not even administer the vaccine.
Issue #1: A vaccinated cat will forever test positive for the virus.
Once a cat has been vaccinated against FIV, they will test positive for the virus for the rest of their life. There is no test that can determine if a cat is testing positive because they truly have the virus or because they have been vaccinated. This causes two very big problems:
- If a vaccinated cat gets lost and is then picked up by animal control or a kill-shelter, that cat will most likely get euthanized for testing positive for FIV, even though the cat is not truly infected.
- If an FIV+ cat is living with an FIV- cat and the FIV- cat has been vaccinated, there is no way to tell if the FIV- cat ever contracts the disease.
Issue #2: The FIV vaccine was only tested against one strain of the virus.
FIV has five known strains, or Clades – A, B, C, D, and E. The vaccine was developed using Clades A and D, but was only tested against Clade A. In the U.S., Clades A and B are the most common – Clade A being the most common in the western side of the country, and Clade B being the most common in the eastern side. Seeing as Clade B is one of the most common strains in the country, and the vaccine was not developed from nor tested against this strain, it unclear how effective the vaccine really is. While the vaccine may supposedly be 85% effective against FIV infection, that is only in regards to one strain of the virus.
Issue #3: The FIV vaccine is adjuvanted.
An adjuvanted vaccine is one that is made from a killed version of the virus with an added adjuvant, or agent that will help to stimulate the immune response of the cat to produce antibodies. The problem with adjuvanted vaccines is that they are suspect in the increase of Vaccine-Associated-Sarcomas (or VAS). Although VAS tumors are very rare (1 in 1,000), they are very aggressive. Even if they are surgically removed, they have a tendency to return even more aggressively than before.
The FIV vaccine is not just one shot – it is a series of three injections, given 2-4 weeks apart. Then, a booster is needed yearly. With so many injections needed, the risk of a VAS tumor developing at the injection site increases. If developed, these types of tumors are more deadly that FIV, so many believe that the vaccine is not worth the risk – the chances of contracting FIV are rare, and even if contracted, a cat can live a long and healthy life with the virus.
As stated previously, the decision that is right for one may not be right for another. The FIV vaccine may be a suitable option for some. It is important to explore all options and discuss them with your veterinarian before making a decision.
Have you had to make the decision of whether or not to vaccinate your cat against FIV? We would love to hear about your decision and the reasons you made it.
Random Felines says
We have to say, mom isn’t in favor of the vaccine for all of those reasons…..but mostly that any vaccinated cat will test positive.
Brian Frum says
I think the “always test positive” thing is a very big problem. I sure hope someone gets this right one of these days.
Summer says
It does sound like the risks of this particular vaccine outweigh the benefits for most cats.
Crepes says
Awesome article. This has stuff in it we didn’t even know. We shared it. Thanks for posting! – Crepes.
Tamago says
Another great post about FIV and thank you for sharing all the information! To vaccinate or not to vaccinate is something I haven’t figured out which is better. As you said, there are so many arguments. As for FIV vaccine, my kitty expert friend mentioned the same issue that you listed on # 1. As our kitties stay indoors, I say no to FIV vaccine for them.
Traveling Cats says
I had no idea that cats tested positive for the virus after the vaccine. Very interesting information.
Kitties Blue says
Mom learned tons of stuff she didn’t know. This is a most excellent post. She is definitely going to talk to our Vet when we get our yearly vaccines. Thanks so much, Mom Emily. We look forward to the third in the series. Love to all and a plethora of kisses and purrs for Sampy from Astrid. She’s not sharing info about the conference as she says most of it was pretty boring. According to her the best part was spending time with human and furry friends.
Purrs and paw-pats, Lily Olivia, Mauricio, Misty May, Giulietta, Fiona, Astrid, Lisbeth and Calista Jo
Kitties Blue says
Sorry, we ended up with some of our post in our comment as it was the last thing we copied. Mom is being really ditzy today! More kisses from A for S.
LP says
Great and informative post! It does sounds as though the risks outweigh the benefits to cats for this particular vaccine.
the critters in the cottage xo
Ellen Pilch says
I keep all mine in and I combo test before anyone gets in. This is a great post though with a lot of things I didn’t know. I will be sharing it.
The Island Cats says
Thanks for sharing this information about the vaccine. You’re right, it depends on the situation and what the cat will be exposed to. The mom has chosen not to have us vaccinated since the chances of us, as indoor cats, of getting FIV is slim.
Ravem says
Since my cats are indoors, I choose not to vaccinate for FIV. I also have the vet use Merial PureVax rabies vaccine, which is non-adjuvanted. It means a yearly shot versus the 3-year rabies vaccine, but I think it’s worth the extra vaccinations to avoid the sarcoma risk.
Fur Everywhere says
Great post, Emily. I didn’t even know a vaccine for FIV existed until recently; my vet does not offer them. We also chose not to vaccinate against FeLV as my kitties don’t ever go outside and aren’t exposed to other cats.
Purrfect Kitties says
Great post! Thanks for sharing, sweeties! 🙂 xx Roxy & Tigerlino <3
da tabbies o trout towne says
great post guys…manee thanx for sharin; we troo lee dinna noe bout de number one izzue…..everee one in TT was vaccinated against FIV anda host of other …..stuff……
we due knot bee leeve in 98 % of the vaccintionz; injected meds, ore oral meds az prescribed coz just like peepulz, whooz ta say itz knot causin a host oh other problemz….
total lee off de subject…but guaranteed… noe one will ever have de convenia injection again….ever…..
Timmy Tomcat says
Dad will never get us that nasty Convena either. Too many sad stories
Purrs Tabbies
da tabbies o trout towne says
N like tuh….we meened ta say peepulz meds !!
Timmy Tomcat says
Very good information and a great series of articles. When Dad found out the kitty he had fostered had FIV he did a lot of research before he came back to eventually move in with us. This information is so important. FIV is like HIV. Think how we have altered our feelings about that over the last 20 years and remember to give an FIV cat a chance.
Timmy and Dad
Dezi and Lexi says
This be a pawsum posty. Fank yous so much fur shawin’. Weez shawin’ it furward.
Luv ya;
Dezi and Lexi
Cathy Keisha says
What an eye-opening post! So the unwashed masses don’t know whether a cat has it or just the shot. Whoa!
Cathy Keisha says
BTW, you need more SHARE buttons. I wanted to share this on G+ but couldn’t find a button.
The Daily Pip says
Wow, this is so interesting and I will also go back and read part 1. That’s scary to think that if you vaccinated your cat and they were lost …they might test positive and be put down. So many shelters still euthanize FIV kitties, unfortunately.
Our kitties are not vaccinated for FIV and I am glad.
Danielle Sullivan says
What an informative post! I have had cats my whole life and never knew all this information about FIV Vaccine. Thanks for sharing.
Lola The Rescued Cat says
This is really interesting. I never knew there was an FIV vaccine. I don’t know if I would do this or not. Hopefully I never have to make that decision.
Hindy Pearson says
Thanks for sharing such helpful info. I had no idea once vaccinated they’d test positive, and you’re so right about what could happen should a cat ever become lost. Too sad. The only vaccines my animals ever get is rabies because they travel, and I’ve never had a problem because of it. You are right – it is a controversial subject. I’m disgusted at the amount of drugs my sweet little Red was being prescribed, so if I can avoid them when possible I will.
Tenacious Little Terrier says
I didn’t know they would test positive after the vaccine. Is this one of the core vaccines for cats? Seems risky.
Golden Daily Scoop says
This is such a helpful and informative post. I had no idea that they can test positive after being vaccinated. Having dogs, I’m not all that familiar with cat vaccines but we have recently started to really look into the vaccines the dogs receive. Reading all this about FIV, I’m not so sure I would approve of it. Thanks for sharing!
Ruth Epstein says
Great post, thanks for all the information
Sonja says
The only vaccine we do is rabies because it’s mandatory for travel. For all the rest we are now doing titter tests because it looks like all the stuff he got as a pup is still good to go so why top up? I had NO idea about the testing positive… that’s a problem!
Jana Rade says
I’m glad that this is one dilemma I don’t have to deal with having dogs only. We do base core vaccines and then titer. But those are very different diseases.
Bryn Nowell says
These are some really important points to consider when deciding what is right for your cat. I think the decision is even more difficult when it’s a multi-cat household. I hope cat owners find your site and use it as the helpful resource that it is when they are deciding what is the best decision for their own household and furry family members.
Dash Kitten Crew says
I didn’t know there was a vaccine! I do know these things are always works in progress but I have a feeling there is still a way to go with this one. We are always up to date on our vaccinations otherwise as it is part of our insurance policies.
Research by people like the Winn Foundation is always ongoing until the correct vaccine is developed. I want a vaccine for this and for FIP!! A dream but it will happen one day!
Tonya Wilhelm says
Our indoor only cats had the recommend kitty vaccinations (cat for the stray adult) once. We do not vaccinate yearly. I know my dog had his puppy set and we titer yearly and at age 7 we still have never needed to booster.
Talent Hounds says
I do not have a kitty at the moment but Nala the Rescue was not vaccinated with this one and was very healthy until almost 19 when her kidneys got messy. She passed almost 2 years ago.
Robin says
This is so important to know! I am someone who is very cautious about vaccines (and medicines in general). I’m not a conspiracy theorist, I just believe that vaccines are not benign. Everything you put in your body does something to your body. There are pros and cons. It is always good to do your research and know that the good in a treatment (or preventative) outweighs the bad for your particular situation. The FIV vaccine has a lot of good intention behind it, but I don’t know that it is a great solution for all cats. I wouldn’t get it for my cats personally.
Beth Patterson says
I can see why this would be a difficult decision to make in some cases. Our cat is an indoor only cat, so I don’t think it is necessary for him.
Jodi says
Sounds to me, like most vaccines, this one is really only any good if you know your kitty is at risk. I” not a huge fan of vaccines, as I feel like a lot of vets recommend them all – even if your pet is at very little risk. Finding a vet you trust to talk the facts with is key. Thanks for sharing all this – I had not idea the FIV vac was so complicated!
Cathy Armato says
This is really fascinating information! I haven’t had a cat in a few years, but I’ve never heard this argument. Thanks for sharing. Over-vaccinating is not at all desirable, in the case of pet vaccinations more is not better.
Love & Biscuits,
Dogs Luv Us and We Luv Them
Christie says
I think that’s the first time I’ve ever heard that getting the vaccine means your cat will test positive for FIV. I wonder why that is specifically? Other vaccines aren’t like that, right?
Sweet Purrfections says
Since Truffle’s littermate developed a VAS after his first vaccine, I am very careful with what vaccinations Truffle receives.