FOI Vaccine failure notifications for MSD Nobivac Myxo- RHD PLUS
Published 14 July 2025
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Request ATI1051
Could you please advise us how many vaccine failure notifications you have had for MSD Nobivac Myxo- RHD PLUS in the following years:
2024
2023
2022
2021
2020
Could you also please advise what the average percentage for vaccine failures is?
Reply
Nobivac Myxo-RHD Plus is a veterinary medicinal product (VMP) used for active immunisation of rabbits from 5 weeks of age onwards to reduce mortality and clinical signs of myxomatosis and rabbit haemorrhagic disease (RHD) caused by classical RHD virus (RHDV1) and RHD type 2 virus (RHDV2).
As per our guidance, we define lack of efficacy as “the apparent inability of an authorised VMP [veterinary medicinal product] to have the expected efficacy in an animal, whether or not the product was used in accordance with the Summary of Product Characteristics (SPC).”
All medicines whether for human or animal use come with risk, and the benefits of use in wider populations need to outweigh the potential risks. Information on adverse events that have been known to occur following administration of a particular product are summarised in sections 3.6/4.6 of the Summary of Product Characteristics (SPC). The SPC is a document describing the properties and the officially approved conditions of use of a medicine. The SPC and associated product information are updated as new information is available, and the latest version of an SPC can be found on our publicly available Product Information Database.
The SPC for Nobivac Myxo-RHD contains the following warnings in section 4.4 regarding lack of efficacy:
High levels of maternally derived antibodies against myxoma virus and/or RHD virus can potentially reduce the efficacy of the product. To ensure the full duration of immunity, vaccination from 7 weeks of age is advised in this case. Rabbits that have been vaccinated previously with another myxomatosis vaccine, or that have experienced natural myxomatosis infection in the field, may not develop an adequate immune response against rabbit haemorrhagic disease following vaccination.
In our response we have included all adverse event reports. This includes reports involving the scenarios specified in section 4.4, reports where the lack of efficacy was not confirmed by testing, reports when the product was used off-label, that is using a medicine in a way that is not specified on the product’s label, reports where more than one product was used, or reports where, on further evaluation, there may have been other reasons for the adverse event occurring.
Please be aware that the data we have provided below are not subject to independent verification and the Veterinary Medicines Directorate (VMD) does not guarantee their accuracy.
Evaluation is dependent on the accuracy and quality of data received from veterinary professionals and animal owners, and reporting frequency can vary over time (reporting frequency may be affected by a product being new to the market or social media interest, for example).
We currently hold complete data up to the end of 2023.
| Year | Number of animals with suspected lack of efficacy following administration of Nobivac Myxo-RHD Plus |
|---|---|
| 2020 | 8 |
| 2021 | 49 |
| 2022 | 37 |
| 2023 | 74 |
Average percentage for vaccine failures
We are unable to provide an average percentage for lack of efficacy across all vaccines because we don’t hold this data in an easily retrievable way. Retrieving this information would be a significant undertaking, therefore we are refusing this request as you currently frame it under Section 12(1) of the FOIA because we estimate that the cost of complying with the request would exceed the appropriate limit, which currently stands at £600.