EMA recommends authorisation of first veterinary vaccine using RNA technology

17 April 2026

Nobivac NXT HCPChFeLV helps protect against common, highly contagious infections in cats

EMA has recommended granting a marketing authorisation in the EU for Nobivac NXT HCPChFeLV, a vaccine for protecting cats against common infectious diseases.

The vaccine targets five pathogens:

• feline herpesvirus type 1, a highly contagious virus causing disease of the upper respiratory tract and the eyes,
• feline calicivirus, a highly contagious virus causing disease of the upper respiratory tract and the mouth,
• feline panleucopenia virus, a highly contagious virus that can cause diarrhoea, vomiting, fever and lethargy and may be fatal, particularly in kittens,
• feline leukaemia virus, which suppresses the immune system and is a common cause of cancer in cats,
• Chlamydia felis, a bacterium that primarily causes eye infections.

The vaccine contains live attenuated (weakened) strains of feline herpesvirus type 1 (G2620A), feline calicivirus (F9), feline panleucopenia (MW-1) and Chlamydia felis (Baker). These weakened strains stimulate an immune response and help the body recognise the microbes and mount a rapid and effective response if the cat comes into contact with them in future.

For feline leukaemia virus, the vaccine also contains self-amplifying RNA packaged in a replication-deficient viral replicon particle. The particle delivers the RNA to cells, enabling the production of a feline leukaemia virus protein that triggers an immune response and prepares the body for future exposure to the virus.

Nobivac NXT HCPChFeLV is the first veterinary vaccine recommended for authorisation in the EU that contains self‑amplifying RNA as an active substance.

Data show the vaccine leads to adequate immune responses and reduces clinical signs of disease

To assess the safety and efficacy of the vaccine, EMA’s veterinary medicines committee (CVMP) considered data from 15 studies conducted in closed animal facilities and one field study carried out in 142 cats under normal everyday conditions.

The data showed that the vaccine triggered adequate immune responses against the five pathogens, with immunity starting around one week after vaccination. The duration of immunity is 3 years for feline panleucopenia virus and 1 year for the four other pathogens.

The studies indicated that the vaccine provides the following clinical benefits in cats:

• a reduction in mortality, clinical signs of feline herpesvirus type 1 infection and spread of the virus through viral shedding,
• a reduction in clinical signs of feline calicivirus infection and viral shedding,
• prevention of mortality, clinical signs of feline panleucopenia virus infection as well as leucopenia (low levels of white blood cells) and viral shedding,
• a reduction in clinical signs of Chlamydia felis infection and shedding of the bacteria,
• a reduction in clinical signs of feline leukaemia virus infection and viraemia (the persistence of the virus in the blood).

The vaccine is generally well tolerated. The most common side effects (occurring in between 1 and 10 out of 100 treated cats) are swelling at the injection site and a high temperature, both lasting for about a day. These side effects are common for most vaccines.

The vaccine is also considered safe for the person giving the vaccine and for the environment when used in accordance with the summary of product characteristics (SPC).

Furthermore, the manufacturing process for the vaccine as well as tests on final batches are adequate to ensure a consistent quality of the vaccine.

The CVMP therefore concluded that the benefits of Nobivac NXT HCPChFeLV outweigh its risks. The CVMP’s recommendation to authorise the vaccine will now be sent to the European Commission, which will issue a legally binding EU-wide decision.