Over the years, one of the most common subjects I have discussed on this blog is vaccination, including their risks and benefits and how pet owners can evaluate them to decide which vaccines are appropriate to give their pets. This is a far more complicated subject than many opponents of vaccination claim.
It is clear that vaccines, like any medical therapy, can cause harm. However, the evidence for specific types of harm is often poor, and the anxiety about vaccination is often based on fear, not real scientific evidence of real risks. Claims that vaccines cause autoimmune disease (1, 2 or behavioral problems, anxieties about “toxins” such as mercury in vaccines, claims that lower “doses” of vaccines are safer than standard volumes (1, 2), and the value of antibody titers as substitutes for vaccination are all subjects I’ve addressed here. There are few simple, absolute answers, but it is clear that the benefits of vaccination almost always outweigh the risks. However, the anti-vaccine movement is alive and well in veterinary medicine, and vaccine opponents have been all too effective at taking the reasonable concerns pet owners may have about vaccine safety and turning them into unreasonable fear.
In human medicine, we have seen the serious consequences of this fear. Vaccine-preventable diseases are making a comeback, and children are being harmed and killed by illnesses they should never have been allowed to contract. The World Health Organization has listed vaccine hesitancy as one of the top ten public health threats we face. One major element to the growing public health threat of vaccine refusal has been the use of exemptions from vaccine requirements for children attending public schools. While there are uncommon medical reasons to avoid vaccinating some children, exemptions based on the religious or personal belief of parents have reduced vaccine coverage and placed all children at greater risk, those who cannot or will not be vaccinated and even those who are, since vaccine protection is excellent but never perfect.
In California, non-medical exemptions were prohibited by law in an effort to better protect public health. Unfortunately, anti-vaccine activists were able to undermine the law by seeking exemptions from deluded or unscrupulous physicianswilling to grant exemptions without legitimate medical and scientific foundations. This loophole had to be addressed in additional legislation giving the state health department authority to review medical exemptions when an excessive number of them are issued by an individual doctor or if a specific school has an excessively low vaccine compliance rate. This is an imperfect solution, but the original law has improved vaccination rates in the state, and it is likely the new measures will be somewhat helpful in reducing the risk posed by individual anti-vaccine activists.
In veterinary medicine, most vaccinations are not legally required for most pets. Vaccination rates are lower, and the occurrence of vaccine-preventable disease are consequently higher, than they should be, but the law considers pets to be property, so there is no real movement to require vaccination even if it is clearly in the best interests of the animals. The exception to this is immunization against rabies, which is often required at the state or local level in pets (almost always in dogs, and sometimes in cats and ferrets) because of the risk infected animals present to humans.
Rabies is almost always fatal, and tens of thousands of people worldwide are killed by it every year. Most of these are exposed by domestic dogs. This is rare in the developed world because of long-standing and successful vaccination campaigns, so many people do not adequately appreciate the danger of reduced vaccine coverage.
Medical exemptions to rabies vaccination are sometimes sought for pets with a history of adverse reactions to rabies vaccine, with conditions that might be exacerbated by vaccination such as autoimmune disease, and of course for many illegitimate reasons such as age or simply the owner’s perception that the vaccine is unsafe or not necessary. Local government often has discretion as to whether to grant such exemptions, and the process and criteria are variable and inconsistent. Anti-vaccine advocates have long wanted to reduce vaccination against rabies (and other diseases), and for the first time a state-level law has been passed which would facilitate this.
The state legislature in Delaware has passed a law allowing veterinarians to exempt individual dogs, cats, and ferrets from rabies vaccine requirements. This law is, unfortunately, a blank check to anti-vaccine vets that contains no protections against the kind of abuse and deception that has plagued efforts to improve compliance with vaccine mandates in humans. The law states:
Exemption from vaccination against rabies may be permitted if a licensed veterinarian has examined the animal and based on the veterinarian’s professional judgment, has certified in writing that at the time, vaccination would endanger the animal’s health because of its infirmity, disability, illness, or other medical considerations.
This allows complete personal discretion on the part of the veterinarian to determine whether or not a pet should be vaccinated without regard to any legitimate scientific standards. Plenty of alternative medicine vets have completely unscientific beliefs about the risks of vaccines, and these doctors will be able to exempt any pet from vaccination based solely on these beliefs. And if clients demand exemptions for reasons that are not scientifically valid, vets will undoubtedly feel pressured to grant them. There are no rules or constraints they can use as justification for denying illegitimate requests.
The law also makes reference to rabies titer testing. It has been argued that since a high rabies titer likely indicates protective immunity in most pets (some challenge testing has been done for this disease), titers could be used in lieu of vaccination in some cases. This is a reasonable argument, and if clear requirements for running and interpreting antibody titers were made, they might be an appropriate alternative to vaccination on a fixed schedule. However, this law does not address any of these issues and merely states that titers can be done, presumably however the individual veterinarian wants.
A titer test, in the case of these medical exemptions, may be administered to assist in determining the need for the vaccination.
This is entirely meaningless since it does not require a titer or define how titers should be measured or used to determine immune status. The complete lack of any input on this law by informed scientific experts in the subject is clear here.
The law is titled “Maggie’s Pet Vaccine Protection Act.” The name refers to a pet whose owner believes her dog died from adverse effects of vaccination. This anecdote is tragic, but it does not demonstrate the owner’s belief to be true. The medical expertise behind the act comes from Dr. John Robb, an anti-vaccine zealot who has been at war against vaccination and much of the veterinary profession for years. Dr. Robb is an example of the kind of veterinarian who will use this new law to reduce the protection against rabies that vaccination provide both pets and humans based only on his own passionate but completely unscientific beliefs about vaccines.
Reasonable changes to vaccination laws based on sound science are totally appropriate. It may be that titers are an effective substitute for vaccination in some cases. However, ill-considered and sloppy laws like this driven by passionate misconceptions about vaccines can only endanger pets and humans. This law is not in the best interests of companion animals or public health, and it is sad that the true danger of such antivaccine activism and laws such as this will only be clear once pets and people start dying of rabies in the U.S. as they do in places where vaccination is not available of common.