A Sunshine Coast vet claims a horse vaccine available to prevent Hendra virus needs further study, particularly of its potential side-effects. The issue is under intense discussion in forums and social media, following the recent illness of a horse in Tin Can Bay. The horse suddenly collapsed, about 10 days after being vaccinated against Hendra virus. It was subsequently discovered the horse did not have Hendra virus, and the concern is that vaccine itself may be the cause of this horses illness. However, local vets and Equine Veterinarians Australia rejected that concern even though test results have not been finalised.Dorothea Hofman, who is also president of the North Coast Active Riders Group, said while horse owners were keen to use a vaccine to protect their horses, feels the present vaccine had not been properly assessed for its side-effects, leaving some in doubt as to whether it caused problems in the process of presenting the disease.“My concern is the vaccine is causing some horses to be unwell,” Ms Hofman said.“Previously IMT( Immune mediated thrombocytopenia) was very rarely heard of in horses in my 30 years as a veterinarian.“I now know of three horses which died from IMT one week to 10 days post-vaccination.”Ms Hofman said the vaccine contained a viral protein fragment and an adjuvant, which is a component added to the vaccine to increase its efficacy. "I personally suspect it is this component that is causing the untoward reactions by over stimulating the immune system to cause some forms of autoimmune disease."“Some horses get wobbly or have nose bleeds and then progress to death. It’s a huge problem,” she said."Some horses display side-effects such as nasal discharges, coat changes and colic post vaccine as well.“I have never seen such a level of severe reactions to vaccines before,” Ms Hofman said.The vaccine came on the market in 2012, and while there was great urgency in developing a vaccine, Ms Hofman believes it needed more testing before its release.“It was rushed; and there is some concern about the product wording, as it refers to the disease being ‘endemic’, whereas it’s more ‘sporadic’,” she said.Ms Hofman acknowledged concern among horse-owners and equine organisations, citing a recent decision by organisers of the Queensland Pony Club State Titles to rescind a motion to make vaccine compulsory for all entrants at the state event.She said owners do definitely want to protect their horses from Hendra virus – but safely so.“Horse-owners want a vaccine; they’re just not happy with this one,” she said.“Many have used the vaccine and some have had problems where horses  became sick or even died.“If there wasn't a problem with the vaccine , horse owners would have be happy and none of this negative vaccine talk would have occurred.”