Understanding Bordetella bronchiseptica vaccines

Bordetella is a family of closely related bacterins which include Bordetella pertussis, Bordetella parapertussis, and Bordetella bronchiseptica. Pertussis and Parapertussis can cause whooping cough in humans. It’s also accepted that Bordetella bronchiseptica (kennel cough) can infect humans.

As its name suggests, kennel cough causes dogs to cough and it’s usually picked up from kennel environments, or from places where dogs are crowded together. This is what they would like you to believe, anyway – but the reality is that the vaccine itself is a source of infection. It’s also possible that when a human is diagnosed with whooping cough, they actually have kennel cough.

An inconvenient but rarely life-threatening disease in dogs

I took the following description of kennel cough from a typical veterinary practice – http://www.vetstream.co.uk: “Most dogs are not really unwell when they have the disease although occasionally they have a high temperature and are a bit ‘out of sorts’ for a day or two. The cough is dry and hacking and it often sounds as if your dog is choking on something stuck in his throat. The cough gets worse for a few days and then gradually goes away after about three weeks.

“Most dogs recover quickly from kennel cough. A young, otherwise healthy dog, should not be unwell with the disease and the cough should get better within 2-3 weeks. Very young or old dogs and dogs with other diseases may be much more severely affected by kennel cough. It would be very unusual indeed for a dog to die as a direct result of catching kennel cough.”

So vets think that kennel cough is not that big of a deal for dogs.

My three elderly previously-vaccinated dogs contracted kennel cough once and survived it; my two nine-month-old pups, who were being given nosodes, didn’t sneeze once – despite nose-to-nose contact. Just thought I’d throw that in!

The vaccine isn’t that great

Because B. pertussis and B. bronchiseptica are so closely related, a group of scientists seeking to understand why there has been a resurgence of whooping cough in vaccinated people used B. bronchiseptica and mice as their model. They found that natural infection induced protection in both the lungs and upper respiratory tract, whereas vaccines conferred protection only in the lungs. The authors suggested that naturally-induced protection is more effective than vaccine-induced protection, and that natural infection could prevent subsequent infections, whereas current vaccines cannot.

It seems that it would be better to let your normal healthy adult dog ‘risk’ contracting kennel cough and get over it, because nature provides better protection than the vaccine.

Most B. bronchiseptica vaccines also come with the parainfluenza virus, both of which are squirted up a dog’s nose. Vaccine company datasheets advise that, “mild discharges from the eyes and nose can occur from the day after vaccination, sometimes accompanied by sneezing and coughing. In some cases, this may persist for up to four weeks”. The datasheets add that antibiotics need to be given to dogs showing severe signs of vaccine-induced kennel cough. Additionally: “Cats, pigs and unvaccinated dogs may react to the vaccine strains with mild and transient respiratory signs.”

So, although kennel cough isn’t that big of a deal, vaccine manufacturers warn in their datasheets that a dog who has been given this vaccine can get a mild case of kennel cough. Vaccinated dogs can also can ‘mildly’ infect other dogs, cats and pigs. It seems to me that the use of the word ‘mild’ refers to the possibility that the lungs are protected but the upper respiratory tract isn’t. Also, it’s clear that dogs with ‘mild’ vaccine-induced kennel cough are still infecting other animals, which isn’t great for kennel owners’ reputations.

To add insult to injury, one paper identified that booster intranasal vaccines may not work for dogs previously exposed to or immunized against B. bronchiseptica! So by giving the Bordetella vaccine to your dog, you provide limited protection and may even give your dog kennel cough; you don’t get long-term immunity; and subsequent shots are unlikely to work. On this basis, it appears counterproductive to use this vaccine.

Vaccine danger to humans

Bordetella vaccine datasheets warn ‘immunocompromised’ humans to avoid contact with vaccinated dogs for six weeks. I mentioned this at one of my evening lectures, and a woman in the audience came up to me afterwards to tell me that she was just getting over whooping cough, and that – yes – it started just after her dog got a kennel cough vaccine.

One study gives credence to the notion that this lady may have contracted kennel cough from her vaccinated dog. The study states that since B pertussis and B. bronchiseptica are nearly identical, the gene detection kits for pertussis infection in humans can mistakenly identify a significant proportion of human kennel cough infections as whooping cough. Oh how ironic – you give your dog a kennel cough jab so he can go in kennels and you can go on holiday, and you end up sneezing and coughing through your vacation.

Another paper states: “B. bronchiseptica causes tracheobronchitis in dogs and atrophic rhinitis in swine; it also causes disease in rabbits and other mammals. B. bronchiseptica infection in humans is considered rare but has been documented in both healthy and immunosuppressed individuals. In healthy individuals, pertussis-like illness and chronic respiratory infection have been reported. Some cases of pertussis-like illness in humans have followed exposure to sick pets or farm animals. The disease is more likely to be severe in individuals who are immunocompromised, such as those with Hodgkin disease, cystic fibrosis, or HIV infection. Pneumonia, sepsis, and death have been reported after infection.”

The paper goes on to state: “Bordetella pertussis, Bordetella parapertussis, and B. bronchiseptica are closely related species that all may cause respiratory tract infection in humans and other mammals and may express many similar virulence factors… With the advent of aerosol vaccination in veterinary clinics for companion animals, human exposure to B. bronchiseptica has likely increased in recent years. Physicians should ask patients presenting with pertussis-like illness whether they have visited a veterinary clinic or have been exposed to a sick or recently vaccinated animal during the week before the onset of symptoms. If the potential for exposure to B. bronchiseptica is present, performance of cultures should be considered before antibiotics are administered.

“Even when administered properly, there may be opportunity for human exposure, especially if the animal sneezes, which is a common occurrence after intranasal administration of a liquid. In addition, the animal may be able to transmit the vaccine strain during the period of active infection.”

One paper queried why pertussis (whooping cough) vaccines fail, and gave as one of its reasons the possibility that other Bordetella species might cause a coughing illness.

Counterproductive vaccine – you’d achieve more by attending to diet

As everyone knows, diet is the cornerstone of health, and good nutrition protects both humans and animals from infection. Whilst we might hypothesise that biologically appropriate food is a safer way of protecting our dogs, there is much science to support our common sense reasoning.

For example, malnutrition was assessed in relation to whooping cough in the UK. Mathematical modelling showed that epidemics were driven by seasonal weather conditions and increases in wheat prices. These two factors predicted the force of infection and the number of people who died. The same authors found a correlation between malnutrition, population size, weather, and measles epidemics.

Another paper states: “Infection and malnutrition have always been intricately linked. Malnutrition is the primary cause of immunodeficiency worldwide, and we are learning more and more about the pathogenesis of this interaction… There is a strong relationship between malnutrition and infection and infant mortality, because poor nutrition leaves children underweight, weakened, and vulnerable to infections, primarily because of epithelial integrity and inflammation.

“In 1968, the World Health Organization published “Interactions of Nutrition and Infection,” which suggested that the relationship between infection and malnutrition was a synergistic one. The Copenhagen Consensus project on hunger and malnutrition even suggested that efforts to provide vitamin A, iron, iodine, and zinc generates higher returns than do trade liberalization or malaria, water, and sanitation programs.”

Vitamin A deficiency increases the risk of developing respiratory disease and chronic ear infections. Vitamin A supplementation sustains gut integrity, lowers the incidence of respiratory tract infections, reduces mortality from diarrhea, and enhances immunity.

Vitamin E enhances immune function and is associated with significant improvement in resistance to influenza virus infection in aged mice and a reduced risk of acquiring upper respiratory infections.

Zinc plays a critical role in the structure of cell membranes and in the function of immune cells. Zinc deficiency reduces nonspecific immunity, including neutrophil and natural killer cell function and complement activity; reduces numbers of T and B lymphocytes; and suppresses delayed hypersensitivity, cytotoxic activity, and antibody production. (Zinc basically helps the immune system to fight disease.)

Patients who are prone to infections and are given high vitamin D doses for one year have a significantly lower risk of developing respiratory tract infections, according to a report in the British Medical Journal. Another study published in Pediatrics (August 2012) showed that incidence of respiratory tract infections among Mongolian children dropped when they were given vitamin D supplements.

Whether you use herbs or nutritional supplements, or feel a raw diet is enough for your dog – one thing is for sure: the Bordetella vaccine can get up your nose, and not necessarily in a good way.

References:

1. Different mechanisms of vaccine-induced and infection-induced immunity to Bordetella bronchiseptica, Microbes and Infection 9 (2007) 442e448

2. J Am Vet Med Assoc. 2002 Jan 1;220(1):43-8., Comparative efficacy of an injectable vaccine and an intranasal vaccine in stimulating Bordetella bronchiseptica-reactive antibody responses in seropositive dogs.

3. J Med Microbiol. 2007 Dec;56(Pt 12):1608-10. Misidentification of Bordetella bronchiseptica as Bordetella pertussis using a newly described real-time PCR targeting the pertactin gene.

4. Clinical Infectious Diseases, Volume 37, Issue 3, Pp. 407-414. Human Illness Associated with Use of Veterinary Vaccines

5. NeoReviews Vol. 129 No. 5 May 1, 2012, pp. 968 -970, (doi: 10.1542/peds.2011-2594)

6. Epidemiol Infect. 1998 Oct;121(2):325-34.

7. Theor Popul Biol. 1997 Oct;52(2):155-63. The dynamics of measles epidemics.

8. Clinical Infectious Diseases (Volume 46, Issue 10, pp 1582-1588)

Advertisements