Filavac VHD K C+V (RHDV1 & RHDV2)

Filavac VHD K C+V is an inactivated bivalent vaccine manufactured by Filavie Laboratories of France, designed to protect rabbits against both classical rabbit haemorrhagic disease (caused by RHDV1) and the variant form (caused by RHDV2). This comprehensive protection against both major calicivirus strains affecting rabbits makes Filavac a valuable tool in the prevention of rabbit haemorrhagic disease worldwide. The vaccine has been licensed in Europe and is also available under emergency or special permit provisions in Australia, Canada, and other countries where RHDV2 has become established.

The vaccine contains inactivated virus material from both RHDV1 and RHDV2 strains, combined with an adjuvant to enhance the immune response. Unlike live recombinant vaccines, the inactivated virus in Filavac cannot replicate in the vaccinated animal, eliminating any possibility of vaccine-induced disease. The vaccine presents as a reddish homogeneous suspension and is administered as a single 0.5 ml subcutaneous injection. Production of the vaccine involves the use of liver tissue from infected rabbits, which is subsequently inactivated and processed to ensure safety while maintaining immunogenicity.

One of the notable advantages of Filavac is its rapid onset of immunity, occurring within just 7 days of vaccination. This quick protection makes the vaccine particularly valuable during disease outbreaks or when rapid immunisation is required. The duration of immunity extends for 12 months, requiring annual revaccination to maintain protection against both virus types.

Filavac does not provide protection against myxomatosis, so in regions where this disease is also present, such as Europe, the UK, and Australia, additional vaccination with a myxomatosis vaccine or a combination product may be necessary. All vaccination protocols should be designed in consultation with a rabbit-savvy veterinarian who can assess local disease risks and individual patient needs to create an optimal protection strategy.

Filavac VHD K C+V is indicated for the active immunisation of rabbits from 10 weeks of age to reduce mortality due to rabbit haemorrhagic disease caused by both classical RHDV1 and type 2 (RHDV2) virus strains. The bivalent nature of this vaccine addresses one of the significant challenges in rabbit disease prevention: the need to protect against both the original RHDV1 strains that have circulated since the 1980s and the newer RHDV2 variant that emerged in 2010 and has since become predominant in many regions.

Classical RHDV1 remains a serious threat to rabbit populations despite the emergence of RHDV2. The virus causes acute necrotising hepatitis with widespread coagulopathy, leading to haemorrhages in multiple organs and death often within 12-72 hours of infection. RHDV1 primarily affects adult rabbits, with young kits under 6-8 weeks typically showing resistance. The virus is highly stable in the environment and can persist for extended periods, making environmental contamination a continuing concern.

RHDV2 represents an evolved threat with characteristics distinct from classical strains. Most significantly, RHDV2 affects rabbits of all ages, including young kits that would otherwise be resistant to RHDV1. The disease course may be more variable, ranging from peracute death to subacute or chronic presentations with jaundice and prolonged illness. Survival rates may be higher than with RHDV1, but surviving and subclinically infected animals can shed virus for extended periods, potentially for months, contributing to ongoing transmission.

The vaccine is particularly important in regions where both virus types co-circulate or where there is uncertainty about which strains are present. In Australia, for example, RHDV1 has been used as a biological control agent against wild rabbits since 1996, while RHDV2 was first detected in 2015 and has since become the predominant strain affecting domestic rabbits. Filavac received emergency permit approval in Australia in 2022 specifically because of its ability to protect against both strains.

Veterinarians may recommend Filavac in various scenarios including routine preventive vaccination, protection during outbreaks, and as part of combination protocols where priming against RHDV2 is desired before administration of live vectored vaccines to overcome vector interference issues.

The dosage protocol for Filavac VHD K C+V involves administration of a single 0.5 ml dose by subcutaneous injection. The vaccine is supplied as a ready-to-use suspension that does not require reconstitution, simplifying preparation and reducing the potential for errors during administration. Before use, the vaccine should be brought to room temperature and the vial shaken well to ensure uniform distribution of the antigenic components throughout the suspension.

Primary vaccination is recommended from 10 weeks of age to achieve the full duration of immunity. However, in situations requiring earlier protection, the vaccine may be used in younger rabbits off-label at the discretion of the attending veterinarian. Rabbits vaccinated before 10 weeks of age should receive a second dose after reaching 10 weeks to ensure full duration of immunity. This approach may be valuable in high-risk situations such as disease outbreaks or when young rabbits are being rehomed.

The onset of immunity is rapid, occurring at approximately 7 days post-vaccination. This quick protection is particularly valuable during outbreak situations or when immediate immunisation is required. The duration of immunity extends for 12 months following vaccination, necessitating annual revaccination to maintain protective immunity against both RHDV1 and RHDV2 strains.

Subcutaneous injection is performed by lifting a fold of loose skin and inserting the needle into the subcutaneous space. The manufacturer typically recommends injection in the scruff of the neck or lateral thoracic wall. Standard aseptic technique should be employed throughout the procedure, including appropriate preparation of the injection site. The site should be monitored for any adverse reactions in the days following vaccination.

The vaccine must be used immediately after first opening the container. Multi-dose vials, when available, should be used according to good veterinary practice with attention to maintaining sterility between withdrawals. Any unused vaccine should be disposed of appropriately according to local regulations for biological materials. The vaccine should not be mixed with any other veterinary medicinal product.

Vaccination should only be performed by or under the direction of a qualified veterinarian who can ensure the rabbit is healthy enough for vaccination and can properly assess the need for RHD protection based on local disease epidemiology.

Filavac VHD K C+V has demonstrated a generally favourable safety profile in clinical studies and field use, though adverse reactions can occur as with any vaccine. The most commonly observed side effect is a temporary increase in body temperature following vaccination. Clinical studies have documented transient fever elevations of up to 1.6°C occurring within the first day after vaccination. This mild febrile response typically resolves spontaneously within a few days and represents a normal physiological reaction to immune system activation.

Local reactions at the injection site are another commonly reported finding with Filavac. These typically present as subcutaneous nodules that may be palpable for extended periods following vaccination. In clinical studies, limited local reactions presenting as nodules up to 10 mm in diameter were observed very commonly, and these may remain palpable for at least 52 days before eventually resolving without treatment. Owners should be counselled that small lumps at the injection site are normal and not cause for alarm unless they grow significantly, become painful, or show signs of infection.

Transient lethargy and reduced appetite may occur in some rabbits during the first 24-48 hours following vaccination. These effects are generally mild and self-limiting as the immune system responds to the vaccine antigens. However, any rabbit that stops eating completely or shows signs of gastrointestinal distress should be evaluated promptly by a veterinarian, as reduced food intake can quickly lead to secondary complications in rabbits.

Serious hypersensitivity reactions have been reported very rarely in post-marketing surveillance. These allergic reactions may present with facial swelling, respiratory distress, collapse, or severe acute lethargy and can potentially be fatal. While extremely uncommon, such reactions require immediate veterinary intervention. Veterinary practices should have appropriate emergency medications available when administering vaccines.

As an inactivated vaccine, Filavac cannot cause vaccine-induced disease or result in viral shedding from vaccinated animals. This safety characteristic is particularly relevant in breeding colonies and when vaccinated rabbits will be in contact with unvaccinated or immunocompromised individuals.

Several contraindications must be carefully considered before administering Filavac VHD K C+V to ensure patient safety and optimal vaccine efficacy. The vaccine is contraindicated in rabbits with known hypersensitivity to the active substances, the adjuvant, or any other excipient in the formulation. Rabbits that have experienced allergic reactions to previous Filavac administration or similar inactivated adjuvanted vaccines should not receive further doses, and alternative vaccination strategies should be explored with a rabbit-savvy veterinarian.

Vaccination should only be performed on healthy animals. Rabbits that are currently ill, stressed, debilitated, or immunocompromised should not receive the vaccine until their condition has resolved and they have returned to normal health status. Administering vaccines to sick animals can impair the immune response, potentially resulting in inadequate protection, and may worsen the animal's underlying condition.

The influence of Filavac vaccination on fertility has not been specifically investigated, which is an important consideration for breeding operations. While the inactivated nature of the vaccine suggests a low likelihood of adverse reproductive effects, pregnant does should be handled with special care to avoid stress during the vaccination procedure and minimise any potential risk of abortion. Vaccination of pregnant animals should proceed only when the veterinarian determines that the benefits clearly outweigh any potential risks.

Rabbits under 10 weeks of age are outside the licensed age range for achieving full duration of immunity. While off-label use in younger rabbits may be considered in high-risk situations, such animals should receive a second dose after reaching 10 weeks of age. Maternal antibodies present in very young kits may interfere with vaccine responses.

Filavac must not be used in food-producing animals in jurisdictions where this restriction applies, such as Australia, due to potential concerns about residues. This is an important consideration for commercial rabbitries producing meat for human consumption.

No information is available regarding the safety and efficacy of this vaccine when used with other veterinary medicinal products. Decisions to use Filavac before or after other medications must be made on a case-by-case basis by the attending veterinarian.

The manufacturer's product information indicates that no specific data is available on the safety and efficacy of Filavac VHD K C+V when used with any other veterinary medicinal product. This absence of formal interaction studies means that decisions to administer Filavac concurrently with, or in close temporal proximity to, other medications must be made on a case-by-case basis by the attending veterinarian based on clinical judgement and risk-benefit analysis.

In clinical practice, Filavac is commonly used as part of comprehensive vaccination protocols alongside other rabbit vaccines. One important application involves using Filavac to prime the immune system against RHDV2 before administration of Nobivac Myxo-RHD PLUS in rabbits where vector interference is a concern. This approach helps ensure adequate RHDV2 protection in rabbits previously vaccinated with older myxomatosis vaccines or those with natural exposure to myxoma virus. A minimum interval of approximately two weeks between vaccines is commonly recommended.

Immunosuppressive medications including corticosteroids may potentially interfere with the development of adequate immune responses to inactivated vaccines like Filavac. Rabbits receiving immunosuppressive therapy should ideally complete their treatment course and recover normal immune function before vaccination. If vaccination cannot be delayed in high-risk situations, the veterinarian should consider potential reduced efficacy and may recommend serological testing to confirm adequate immune response.

Non-steroidal anti-inflammatory drugs such as meloxicam, commonly used for pain management in rabbits, are not known to significantly interfere with inactivated vaccine responses. However, because NSAIDs can mask early signs of adverse reactions including fever, some veterinarians may prefer to avoid concurrent administration unless pain management is specifically required for another indication.

The adjuvant included in Filavac's formulation may theoretically interact with other adjuvanted vaccines if administered simultaneously or in rapid succession. Spacing out the administration of different adjuvanted products may be advisable when multiple vaccines are required as part of a comprehensive disease prevention program.

Probiotic supplements and gastrointestinal support products commonly used in rabbit medicine are not expected to interact with Filavac. Nonetheless, rabbit owners should inform their veterinarian about all supplements and medications their rabbit is receiving.

Several important precautions and warnings must be observed when using Filavac VHD K C+V to ensure safe and effective vaccination outcomes. The fundamental precaution is that only healthy rabbits should be vaccinated. A thorough clinical examination should be performed prior to vaccination to identify any signs of illness, stress, or immunocompromise that might contraindicate vaccination or impair the immune response. Rabbits should be alert, eating normally, and showing no signs of respiratory, gastrointestinal, or other illness.

Filavac provides protection specifically against RHDV1 and RHDV2 and does not protect against myxomatosis. In regions where myxomatosis is endemic, such as Europe, the UK, and Australia, additional vaccination with an appropriate myxomatosis vaccine or combination product will be necessary to ensure comprehensive protection. Rabbit owners should be clearly informed about what diseases the vaccine does and does not protect against to prevent misunderstanding about their rabbit's protection status.

Proper handling and storage of the vaccine is essential to maintain its potency and effectiveness. The vaccine must be stored and transported refrigerated between 2°C and 8°C and must not be frozen. Before use, the vaccine should be allowed to reach room temperature and shaken well to ensure the suspension is homogeneous. The vaccine should appear as a reddish homogeneous suspension; any product that appears abnormal should not be used.

The vaccine must be used immediately after first opening the container, and unused vaccine cannot be stored for later use. Disposal of vaccine waste should follow local regulations for biological materials. The vaccine should not be mixed with any other veterinary medicinal product.

Owners should be counselled about expected post-vaccination effects and when to seek veterinary attention. Normal responses may include mild fever, reduced activity for 24-48 hours, and localised swelling at the injection site. Any signs of severe allergic reaction, complete loss of appetite lasting more than 12-24 hours, or other concerning symptoms warrant immediate veterinary evaluation.

Accurate record-keeping of vaccination details including date, batch number, injection site, and any reactions observed is essential for proper follow-up care, adverse event monitoring, and planning future vaccinations.

Proper storage and handling of Filavac VHD K C+V is critical to maintaining vaccine potency and ensuring effective protection for vaccinated rabbits. The vaccine must be stored and transported under refrigerated conditions, maintaining temperatures between 2°C and 8°C throughout the distribution chain and during storage at the veterinary practice. The cold chain must be preserved from manufacture through to the point of administration, as temperature excursions can compromise vaccine viability.

The vaccine must not be frozen under any circumstances. Freezing causes structural damage to the vaccine components and can render the product ineffective. If there is any suspicion that the vaccine may have been exposed to freezing temperatures, it should not be used. Similarly, exposure to temperatures above the recommended range can cause degradation of the antigenic components.

Vaccine vials should be stored in the outer carton to protect them from light exposure. Ultraviolet radiation and prolonged exposure to ambient light can degrade vaccine components over time. The outer packaging provides additional protection during handling and helps maintain temperature stability.

The shelf life of Filavac as packaged for sale varies by presentation and should be confirmed on the product labelling. Veterinary practices should implement first-in-first-out stock rotation procedures to ensure vaccines are used before their expiration date. The expiry date is clearly marked on both individual vials and outer packaging and should be verified before each use.

Once opened, the vaccine must be used immediately. Multi-dose vials, when available, should be used according to good veterinary practice guidelines, maintaining strict aseptic technique during each withdrawal to prevent contamination. Any unused vaccine remaining after a vaccination session cannot be stored and must be disposed of appropriately according to local regulations for biological waste materials.

Before administration, the vaccine should be brought to room temperature and shaken well to ensure the suspension is homogeneous. The vaccine should appear as a reddish homogeneous suspension. Any product that appears abnormal in colour, consistency, or clarity, or that contains visible particles or precipitates, should not be used and should be returned to the supplier for investigation.

Filavac VHD K C+V has been developed for use across all breeds of domestic rabbits, with no breed-specific contraindications or dose modifications identified. The vaccine's safety and efficacy profile has been established through clinical trials and extensive field use, demonstrating applicability across the diverse range of rabbit breeds kept as pets, in breeding programs, and in commercial operations.

Dwarf breeds including Netherland Dwarf, Holland Lop, Mini Rex, Mini Lop, and Polish rabbits receive the same 0.5 ml dose as larger breeds. The immune response to vaccination is determined by the antigenic content rather than the animal's body mass. However, careful attention to injection technique is particularly important in these small rabbits to ensure proper subcutaneous placement and minimise discomfort. The lateral thoracic wall or scruff provides suitable injection sites even in very small individuals.

Giant breeds such as Flemish Giant, Continental Giant, British Giant, and French Lop do not require increased vaccine doses. The standard single dose provides adequate antigenic stimulation regardless of body size. Owners of giant breeds may be less likely to notice small injection site reactions due to the proportionally larger body size, but monitoring for adverse reactions remains important.

Lop-eared breeds including English Lop, French Lop, Holland Lop, and Mini Lop require no special considerations for vaccination beyond standard protocols. The subcutaneous injection site in the thoracic wall or scruff is not affected by ear conformation.

Angora breeds and Rex breeds with their distinctive coat characteristics may require careful parting of the fur to visualise the skin properly for injection. Ensuring proper needle placement through the skin into the subcutaneous space is important regardless of coat type.

Age considerations apply across all breeds. The licensed vaccination age begins at 10 weeks for full duration of immunity. Senior rabbits should continue to receive annual vaccinations, as protection against RHD remains critically important throughout life. Very young rabbits under 10 weeks may receive off-label vaccination in high-risk situations but should be revaccinated after 10 weeks of age.

Several related vaccines are available for protection against rabbit haemorrhagic disease, each with specific characteristics that may make them more or less suitable depending on individual circumstances, geographic location, and disease risk profile. Eravac is another inactivated adjuvanted vaccine produced by Hipra Laboratories that provides protection specifically against RHDV2. Unlike Filavac's bivalent formulation, Eravac targets only RHDV2 and does not protect against classical RHDV1. Both vaccines share similar characteristics including rapid 7-day onset of immunity and inactivated formulation, but Filavac offers broader coverage against both major RHD virus types.

Nobivac Myxo-RHD PLUS is a live recombinant vector vaccine manufactured by MSD Animal Health that provides comprehensive protection against myxomatosis, RHDV1, and RHDV2 in a single annual injection. This combination vaccine offers broader disease coverage than Filavac by including myxomatosis protection. However, Nobivac has a slower onset of immunity (3 weeks versus 7 days) and is subject to vector interference issues in rabbits previously exposed to myxoma virus. Filavac is often recommended prior to Nobivac administration to overcome this interference.

In the United States, where neither Filavac nor Eravac is routinely available, the Medgene RHDV2 vaccine provides protection against RHDV2. This recombinant subunit vaccine uses different technology than the inactivated European vaccines, employing baculovirus expression to produce viral capsid proteins. It requires a two-dose primary series administered 21 days apart and does not protect against RHDV1.

In Australia, Cylap RCD vaccine was historically used to protect against RHDV1, but its protection against RHDV2 was limited. The emergency approval of Filavac in 2022 addressed the critical need for RHDV2 protection in Australian rabbits. Cylap remains available for commercial rabbits where Filavac use is restricted.

The choice between these vaccines depends on geographic location, local disease prevalence, previous vaccination history, regulatory availability, and individual circumstances. In many cases, combination vaccination protocols using multiple products may provide the most comprehensive protection. All vaccination decisions should be made in consultation with a rabbit-savvy veterinarian who can assess individual risk factors and design an appropriate vaccination strategy.