Eravac (RHDV2)

Eravac is an inactivated adjuvanted vaccine specifically developed to protect rabbits against rabbit haemorrhagic disease caused by RHDV2 (rabbit haemorrhagic disease virus type 2), a highly virulent calicivirus variant that emerged in France in 2010 and has since spread worldwide. Manufactured by Laboratorios Hipra S.A. of Spain, Eravac was one of the first vaccines developed to address the emerging RHDV2 threat and received European Union licensing in 2016. The vaccine has proven instrumental in protecting pet rabbits during the RHDV2 epidemic that swept through Europe and beyond.

The vaccine contains inactivated RHDV2 strain V-1037, which has been rendered non-infectious while retaining its immunogenic properties. An adjuvant is included in the formulation to enhance the immune response, ensuring robust and lasting protection against RHDV2 infection. The vaccine presents as a reddish homogeneous suspension and is administered as a 0.5 ml dose via subcutaneous injection. Unlike live recombinant vaccines, Eravac cannot replicate in the vaccinated animal, making it an extremely safe option with no risk of vaccine-induced disease.

One of the key advantages of Eravac is its rapid onset of immunity, which occurs within just 7 days of vaccination. This makes it particularly valuable during disease outbreak situations where immediate protection is needed, compared to live vectored vaccines that may require 3 weeks to develop full immunity. The duration of immunity is 12 months, necessitating annual revaccination to maintain protection.

Eravac provides protection specifically against RHDV2 and does not protect against classical RHDV1 strains or myxomatosis. Therefore, in regions where all three diseases are present, Eravac may be used in combination with other vaccines to provide comprehensive protection. All vaccination decisions should be made in consultation with a rabbit-savvy veterinarian who can assess the local disease situation and design an appropriate vaccination protocol for each individual rabbit.

Eravac is indicated for the active immunisation of rabbits from 30 days of age onwards to reduce mortality due to rabbit haemorrhagic disease caused by RHDV2 strains. The vaccine was specifically developed in response to the emergence and rapid spread of RHDV2, which was first identified in France in 2010 and quickly became the predominant cause of rabbit haemorrhagic disease across Europe, subsequently spreading to other continents including Australia and the Americas.

RHDV2 represents a particularly significant threat to rabbit populations for several reasons that distinguish it from classical RHDV1. Unlike RHDV1, which typically spared young rabbits under 6-8 weeks of age, RHDV2 can cause fatal disease in rabbits as young as 15-30 days old. This expanded age susceptibility means that young kits, previously considered protected by age resistance, are now at risk. Additionally, RHDV2 often presents with a more variable and sometimes protracted disease course, and crucially, vaccines against classical RHDV1 do not provide reliable cross-protection against RHDV2.

The vaccine is recommended for use in areas where RHDV2 is epidemiologically relevant, which now encompasses most of Europe, the United Kingdom, Australia, and parts of North America where the virus has become established. Even indoor rabbits should be considered for vaccination, as the virus is highly stable in the environment and can be introduced into the home on clothing, footwear, hay, vegetables, or via insects. The virus can survive for extended periods on surfaces and in organic materials, making environmental contamination a persistent risk.

Veterinarians often recommend Eravac as part of a comprehensive vaccination strategy, particularly when rapid RHDV2 protection is needed or when transitioning rabbits from older vaccination protocols. The vaccine is commonly used to prime the immune system against RHDV2 before administration of combination vaccines in situations where vector interference might otherwise compromise protection.

Eravac may also be used in breeding colonies, rescue centres, and commercial rabbit operations where the rapid onset of immunity provides critical protection during disease outbreaks. The ability to vaccinate from 30 days of age allows protection of young rabbits earlier than many other vaccines permit.

The dosage protocol for Eravac is straightforward, consisting of a single 0.5 ml dose administered by subcutaneous injection in the lateral thoracic wall. The vaccine is supplied as a ready-to-use suspension that requires no reconstitution, simplifying the preparation process in veterinary practice. Before administration, the vaccine vial should be brought to room temperature and shaken well to ensure uniform distribution of the antigenic material throughout the suspension.

Primary vaccination can commence from 30 days of age, making Eravac one of the earlier-age vaccines available for RHDV2 protection. This is particularly important given that RHDV2, unlike classical RHDV1, can cause fatal disease in very young rabbits. The onset of immunity occurs at 7 days post-vaccination, which is considerably faster than live vectored vaccines and makes Eravac valuable for rapid protection during outbreak situations or when immediate travel or rehoming is planned.

The duration of immunity is licensed for 12 months, requiring annual revaccination to maintain protective immunity. Revaccination should be administered at 12-month intervals following the primary vaccination. If vaccination lapses significantly beyond this interval, a single dose should be sufficient to restore immunity in previously vaccinated animals, though the veterinarian may recommend additional precautions depending on local disease risk.

The subcutaneous injection technique involves lifting a fold of skin in the lateral thoracic wall area and inserting the needle into the subcutaneous space. Standard aseptic technique should be employed throughout the procedure. The injection site should be noted in the patient's records and monitored for any adverse reactions in the days following vaccination.

The vaccine must be used immediately after first opening the container. Any unused vaccine should not be stored for later use and must be disposed of appropriately according to local regulations for biological materials. The vaccine should not be mixed with any other veterinary medicinal product.

As with all vaccines, administration 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 RHDV2 protection based on local disease prevalence and the individual rabbit's circumstances.

Eravac generally demonstrates a favourable safety profile, with most rabbits tolerating vaccination well. However, as with any vaccine, adverse reactions can occur and owners should be informed about what to expect following vaccination. The most commonly reported side effect is a temporary increase in body temperature, which has been observed very commonly (affecting more than 1 in 10 animals) in clinical studies, with elevations of up to 1.6°C documented within the first day after vaccination.

Local reactions at the injection site are another very common finding following Eravac administration. These typically present as subcutaneous nodules that may be palpable for extended periods following vaccination. In clinical studies, nodules up to 10 mm in diameter were observed when double doses were administered. These localised reactions generally resolve without treatment over time, though they may remain palpable for at least 52 days in some cases. Owners should be advised that small lumps at the injection site are a normal response and not cause for concern unless they grow, become painful, or show signs of infection.

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

Serious hypersensitivity reactions have been reported very rarely in post-marketing surveillance. Signs of severe allergic reaction may include facial swelling, respiratory distress, collapse, or acute lethargy. These reactions require immediate veterinary intervention. Veterinary practices should have appropriate emergency medications available when administering any vaccines, though anaphylactic reactions to Eravac are exceptionally uncommon.

As inactivated vaccines cannot replicate, there is no risk of vaccine-induced disease or viral shedding. This provides an important safety advantage in certain situations, particularly in breeding colonies or when vaccinated rabbits will be in contact with immunocompromised individuals.

Several contraindications must be considered before administering Eravac to ensure patient safety and optimal vaccine efficacy. The vaccine is contraindicated in rabbits with known hypersensitivity to the active substance, the adjuvant, or any other component of the formulation. Rabbits that have experienced allergic reactions to previous Eravac administration or similar inactivated adjuvanted vaccines should not receive further doses, and alternative vaccination strategies should be discussed with a rabbit-savvy veterinarian.

Vaccination should only be administered to 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. Underlying illness can impair the immune response to vaccination, potentially resulting in inadequate protection, and the stress of vaccination may worsen the rabbit's condition.

The influence of vaccination on fertility in breeding rabbits has not been investigated, which is an important consideration for breeders. While the inactivated nature of the vaccine suggests a low likelihood of reproductive effects, pregnant does should be handled with special care during vaccination to avoid stress and minimise any risk of abortion. The manufacturer advises that pregnant does should be vaccinated only when the benefits clearly outweigh any potential risks.

Rabbits under 30 days of age should not be vaccinated with Eravac, as safety and efficacy have not been established in this very young age group. Maternal antibodies present in young kits may also interfere with vaccine responses, though this is less of a concern with Eravac compared to some other vaccines.

No specific information is available regarding the safety and efficacy of Eravac when used concurrently with other veterinary medicinal products. Therefore, the decision to use this vaccine before or after any other medication must be made on a case-by-case basis by the attending veterinarian. This is particularly relevant when multiple vaccines are being administered as part of a comprehensive protection protocol against myxomatosis, RHDV1, and RHDV2.

Currently, no specific data is available from the manufacturer regarding the safety and efficacy of Eravac when used with other veterinary medicinal products. This absence of formal interaction studies means that decisions to administer Eravac before, after, or concurrently with other medications must be made on an individual case basis by the attending veterinarian, weighing the potential benefits against any theoretical risks.

In practice, Eravac is often used as part of combination vaccination protocols alongside other rabbit vaccines. A common approach in the UK and Europe involves administering Eravac to prime the immune system against RHDV2, followed by Nobivac Myxo-RHD PLUS for comprehensive protection against myxomatosis, RHDV1, and RHDV2. This strategy helps overcome the vector interference phenomenon that can occur when rabbits previously exposed to myxoma virus receive vectored vaccines. A minimum interval of two weeks between different vaccines is commonly recommended, though specific guidance varies.

Immunosuppressive medications such as corticosteroids may potentially interfere with the development of adequate immune responses to inactivated vaccines. Rabbits receiving immunosuppressive therapy should ideally complete their treatment and recover normal immune function before vaccination. If vaccination cannot be delayed in high-risk situations, the veterinarian should consider the potential for reduced efficacy.

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

Probiotic supplements and other gastrointestinal support products commonly used in rabbit medicine are not expected to interact with Eravac. However, rabbit owners should inform their veterinarian of all supplements and medications their rabbit is receiving to allow for comprehensive assessment of any potential interactions.

The adjuvant included in Eravac's formulation may theoretically interact with other adjuvanted products if administered simultaneously or in close succession, potentially affecting the nature of the immune response. Spacing out the administration of different adjuvanted vaccines is generally advisable.

Several important precautions and warnings must be observed when using Eravac to ensure safe and effective vaccination outcomes. The fundamental precaution applies to all vaccines: only healthy animals 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.

The vaccine is specifically formulated for protection against RHDV2 only. Eravac does not provide cross-protection against classical RHDV1 strains, and no protection is afforded against myxomatosis. In regions where these diseases are also present, additional vaccination with appropriate products will be necessary to ensure comprehensive protection. Rabbit owners should be clearly informed about what the vaccine does and does not protect against to avoid false assumptions about their rabbit's protection status.

Vaccination is recommended only in areas where RHDV2 is epidemiologically relevant. However, given the widespread global distribution of RHDV2 and its high environmental stability, most rabbit populations should now be considered at risk. Even indoor-only rabbits can be exposed through contaminated materials brought into the home.

Proper handling and storage of the vaccine is essential to maintain potency. The vaccine must be stored and transported refrigerated at 2°C to 8°C and must not be frozen. It should be protected from light by keeping vials in the outer carton. Before use, the vaccine should be allowed to reach room temperature and shaken well to ensure homogeneity. The shelf life is 2 years when stored correctly, and the vaccine must be used immediately after opening.

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

Accurate record-keeping of vaccination details including date, batch number, and administration site is essential for proper follow-up care and in case of any adverse event reporting requirements.

Proper storage and handling of Eravac is essential to ensure the vaccine remains potent and effective throughout its shelf life. The vaccine must be stored and transported under refrigerated conditions, maintaining temperatures between 2°C and 8°C at all times. The cold chain must be maintained from the point of manufacture through distribution and storage at the veterinary practice until the moment of administration. Any breaks in the cold chain may compromise vaccine viability.

The vaccine must not be frozen under any circumstances. Freezing can damage the vaccine's structure and antigenic properties, potentially rendering it ineffective. If there is any suspicion that the vaccine may have been frozen at any point, it should not be used. Similarly, exposure to temperatures above the recommended range can cause degradation of the vaccine components.

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

The shelf life of Eravac as packaged for sale is 2 years from the date of manufacture when stored under appropriate conditions. 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 checked before each use.

Once the vial is opened, the vaccine must be used immediately. There is no shelf life after first opening, and any unused vaccine cannot be stored for later use. Partially used vials must be disposed of appropriately according to local regulations for biological waste materials. The vaccine should not be mixed with any other veterinary medicinal products.

Before administration, 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 vaccine that appears abnormal in colour or consistency, or contains visible particles or precipitates, should not be used.

Eravac has been developed and tested for use across the diverse range of domestic rabbit breeds, with no breed-specific contraindications or dose adjustments identified. The vaccine's safety and efficacy have been established in commercial rabbit populations, and it is widely used in pet rabbits of all breeds throughout Europe, the UK, Australia, and other regions where RHDV2 is present.

Dwarf breeds such as Netherland Dwarf, Holland Lop, Mini Rex, and Polish rabbits receive the same 0.5 ml dose as larger breeds. Despite their small body size, the immunological response to vaccination is determined by the antigen content rather than body mass. However, particular attention should be paid to injection technique in very small rabbits to ensure proper subcutaneous placement and minimise discomfort.

Giant breeds including Flemish Giant, Continental Giant, British Giant, and French Lop do not require increased vaccine doses. The standard dose provides adequate antigenic stimulation regardless of body size. Owners of giant breeds should be informed that localised injection site reactions may appear proportionally smaller relative to their rabbit's body size but still warrant monitoring.

Lop-eared breeds including French Lop, English Lop, Holland Lop, and Mini Lop require no special considerations beyond standard vaccination protocols. The injection is typically administered in the lateral thoracic wall rather than areas near the ears, so ear conformation does not affect administration technique.

Rex breeds and Angora breeds with different coat types may require slight adjustment in injection site preparation to ensure proper skin access, but vaccination protocols remain otherwise unchanged. Dense-coated breeds may benefit from careful parting of the fur to allow proper skin visualisation during injection.

Age considerations apply equally across all breeds. The vaccine can be administered from 30 days of age, which is earlier than many other rabbit vaccines. This early age eligibility is particularly valuable given that RHDV2, unlike classical strains, can cause fatal disease in very young rabbits. Senior rabbits should continue to receive annual vaccinations, as protection against RHDV2 remains important throughout life.

Several related vaccines are available for protection against rabbit haemorrhagic disease, each with specific characteristics that may make them more appropriate in different situations. Filavac VHD K C+V is another inactivated adjuvanted vaccine that provides protection against both RHDV1 and RHDV2, unlike Eravac which targets RHDV2 specifically. Filavac may be preferred when protection against both virus types is desired from a single inactivated vaccine, particularly in regions where classical RHDV1 remains a concern alongside RHDV2.

Nobivac Myxo-RHD PLUS is a live recombinant vector vaccine that provides comprehensive protection against myxomatosis, RHDV1, and RHDV2 in a single annual injection. While Nobivac offers broader disease coverage, its onset of immunity (3 weeks) is slower than Eravac's (7 days). Additionally, the phenomenon of vector interference means that rabbits previously vaccinated with other myxomatosis vaccines may benefit from Eravac administration to prime immunity against RHDV2 before receiving Nobivac.

In the United States, where neither Eravac nor Nobivac vaccines are available, the Medgene RHDV2 vaccine provides protection against RHDV2. This recombinant subunit vaccine uses baculovirus expression technology to produce viral capsid proteins and requires a two-dose primary series administered 21 days apart, followed by annual boosters.

Yurvac RHD is a newer vaccine from Hipra (the same manufacturer as Eravac) that has been developed against more recent highly virulent strains of RHDV2. This vaccine is particularly relevant given emerging concerns about highly virulent RHDV2 variants that may have evolved since the original vaccines were developed.

The choice between these vaccines depends on multiple factors including geographic location, local disease prevalence, previous vaccination history, urgency of protection required, and owner preferences. In many cases, combination protocols using multiple vaccines may be recommended to ensure optimal protection. All vaccination decisions should be made in consultation with a rabbit-savvy veterinarian who can assess individual circumstances and design an appropriate vaccination strategy tailored to each rabbit's needs and risk factors.