Naming diseases: first do no harm.

The World Organisation for Animal Health (OIE) plays an important leadership role in global efforts to prevent, detect and respond to infectious disease threats. Since 1924, the OIE has helped Member Countries to prevent the spread of animal diseases, while facilitating safe agricultural trade. In recent years, the OIE has also increasingly focused on the biosecurity objectives of preventing unauthorised access to and loss, theft, misuse or diversion of dangerous pathogens, including their intentional release. Preventing the intentional introduction of animal disease is critical not only because of the significant economic impact that animal diseases can have on a nation's economy, but also because a number of animal diseases can affect humans. Over 60% of human diseases are of animal origin. Therefore, the OIE, working in conjunction with its partner organisations, the Food and Agriculture Organization of the United Nations and the World Health Organization, has become a leading international organisation for the control of global infectious disease in humans as well as in animals.

With cases documented in more than 170 countries, the global swine flu pandemic that erupted in spring 2009 remains a serious public health problem. Caused by a strain of H1N1 influenza virus, which is normally found in pigs, the flu now known as novel H1N1 has so far been less severe than regular seasonal flu in terms of deaths and hospitalizations. Yet given its remarkable capacity for human-to-human transmission and a widespread lack of immunity among potentially exposed people, it’s likely the number of cases will rise during the flu season later this fall and winter, according to many public health experts. Given that possibility, enormous resources are being mobilized to address novel H1N1, with an emphasis on vaccine development, education, and efforts to its limit its movements among human communities. Yet one potential source of the original outbreak—factory swine farming in concentrated animal feeding operations (CAFOs)—has received comparatively little attention by public health officials. CAFOs house animals by the thousands in crowded indoor facilities. But the same economy-of-scale efficiencies that allow CAFOs to produce affordable meat for so many consumers also facilitate the mutation of viral pathogens into novel strains that can be passed on to farm workers and veterinarians, according to Gregory Gray, director of the Center for Emerging Infectious Diseases at the University of Iowa College of Public Health. “When respiratory viruses get into these confinement facilities, they have continual opportunity to replicate, mutate, reassort, and recombine into novel strains,” Gray explains. “The best surrogates we can find in the human population are prisons, military bases, ships, or schools. But respiratory viruses can run quickly through these [human] populations and then burn out, whereas in CAFOs—which often have continual introductions of [unexposed] animals—there’s a much greater potential for the viruses to spread and become endemic.” Gray says workers exposed routinely to livestock can pass these zoonotic infections—which transmit readily among humans and animals—on to the wider public. However, public health agencies that monitor risks from zoonotic infections routinely overlook CAFO workers, according to Ellen Silbergeld, a professor at the Johns Hopkins Bloomberg School of Public Health. And animal disease sampling data collected by the food animal industry typically are not shared publicly, according to Gray, although such data could reveal how novel pathogens evolve in CAFOs and how they might move among animals, workers, and the broader community. Experts believe that without these data, society has a diminished capacity to detect and respond to new zoonotic threats before they become more widespread.

According to some definitions health is the absence of disease, thus it can be said that disease is the lack of health. However, it is difficult to agree with such a simplified approach, as health is not just a synonym for health status. The term health status has a much wider implication and it implies not only the state of health i.e. if the animals are healthy or not, but also is the herd is free from infectious diseases, and the implementation of biotechnological measures for the maintenance of productivity. It is possible that the animals have a poor health status (presence of latent infections) but are clinically healthy and productive. Similarly, it is possible that the animals are in a good health status, but the management, housing, care and diet are not adequate, resulting in the manifestation of clinical signs of disease. A disease is essentially the absence of health, i.e. a deviation from the harmonious functioning of some organs or organisms, which can then be clearly manifested through certain symptoms or signs, which is also called the clinical form of the disease. However, very often some diseases are present in a subclinical or latent form, when they can only be detected by one of the methods of serodiagnosis, but the best and safest way is by identifying the cause or by considering some parameters that indicate a decline in production. Health is a prerequisite for the profitability of keeping and raising animals. A healthy animal produces a healthy product that, after processing, becomes food for humans. In this way, human health is also protected. Animal proteins are an indispensable nutrient in the diet of the population. Unfortunately, animal health does not depend only on measures implemented in an area, country, or even a continent, but on a wider, global space and mode of transmission, most often of the causative agents of infectious diseases, which cause enormous damage to the economies of countries relaying on animal husbandry. Under the patronage of world organizations, the World Health Organization (WHO), the Food and Agriculture Organization (FAO) and the World Organization for Animal Health (OIE), of which almost all countries are members, universal rules and guidelines are being prepared and adopted for monitoring, detection, prevention of spreading, and control and eradication animal diseases. Each country adopts health care programs according to its potentials and accepts the obligation to report to world organizations, primarily to OIE, in the event of certain diseases of terrestrial and aquatic animals. Veterinary services have the greatest responsibility for animal health and food of animal origin, they have the role of public service in the protection of public health. Some countries have declared veterinary activity a common good, and the initiative is to define this service on a global scale. It is known that there are 1415 pathogens that cause infectious diseases in humans. Over 60% of human infectious diseases are of a zoonotic nature. At least 75% of emerging infectious diseases in humans are of animal origin. Every year, five new infectious diseases in humans appear, and most of them are of animal origin. Out of the pathogens with potential use for bioterrorist purposes, 80% of them are zoonotic pathogens. Disease prevention (preventive health care) will be a priority for veterinary and health systems and services in the future. In addition to the immunological measures that are being implemented (vaccination), epidemiological services have a wide range of options at their disposal that will become more important. Veterinary medicine works very effectively on the protection of farm breeding of various species of animals by prescribing the consistent application of health, zoohygiene and biosafety measures and procedures. In that way, the contact of the causative agent of the disease with the animal is prevented, which has proven to be the key factor in preventing the occurrence of mass diseases (epidemics, pandemics and other forms of infectious diseases).

Wild animal diseases are a global growing concern, given the threat that they pose to animal health and their zoonotic potential. The World Organisation for Animal Health (OIE) was among the first organisations to recognise the importance of having a comprehensive knowledge of the disease situation in wild animals, collecting information on wildlife diseases worldwide since 1993, when for the first time an annual questionnaire was distribute by OIE to members Countries in order to collect qualitative and quantitative data on selected diseases in wild animals. Starting with 2008 until 2012 an updated version of questionnaire was circulated to allow for identifying wildlife species by their Latin name and by their common names in the 3 OIE official languages (English, French, and Spanish). This specific functionality was then implemented in the World Animal Health Information System (WAHIS) in 2012, when this information was made available to the public through WAHIS-Wild Interface.

Only two international organisations have a global legal framework that allows them to request, collect, and release global animal or human health information: the World Organisation for Animal Health (OIE), which is responsible for transparently assessing the global animal health situation, and the World Health Organization (WHO), which is responsible for transparently assessing the global human health situation. Legal instruments bind OIE Member Countries and WHO States Parties (OIE's Standards and WHO's International Health Regulations [IHR]) to report certain disease outbreaks and public health events to their respective organisations. OIE Member Countries must report exceptional epidemiological events involving any OIE-listed diseases, including zoonoses. Moreover, they must notify the OIE of any emerging animal diseases. The IHR require WHO Member States to provide notification of events that may constitute a public health emergency of international concern. These include, but are not restricted to, outbreaks of communicable diseases of international concern. In both organisations, in addition to reporting outbreaks and exceptional events, Members also monitor diseases on an ongoing basis and provide regular reports. To complement these passive surveillance mechanisms, the OIE, WHO and the Food and Agriculture Organization of the United Nations track signals from informal sources of outbreaks of animal and zoonotic infectious diseases, thereby increasing the sensitivity of worldwide disease reporting. The formal information collected is disseminated to Members and the general public through various communication channels, so that countries can apply science-based measures to prevent further disease spread. Both the OIE and WHO reporting systems are supported by a range of coordinating activities to ensure the proper flow of information between national and international levels.

Coronavirus disease 2019 (COVID-19) has exposed serious deficiencies in the current legal framework to protect wild animal health, and consequently human health. As noted by the World Organisation for Animal Health (OIE), animal health and welfare are inextricably linked. However, there is no international agreement to promote animal welfare and neither the Convention on International Trade in Endangered Species of Wild Fauna and Flora nor the Convention on Biological Diversity, adequately address the welfare of the species they seek to conserve. While the OIE provides guidance on animal health and welfare standards for common agricultural species, it has provided limited guidance for the farming of wild species. China’s wildlife farming industry has been linked with the spread of COVID-19 but, to date, China has introduced few national welfare controls to protect the health of wild animals bred for human consumption. In the wake of COVID-19, these omissions must be remedied to provide appropriate safeguards to ensure animal health and welfare and protect public health.

For over two decades, the World Organisation for Animal Health (OIE) has engaged in combatting antimicrobial resistance (AMR) through a One Health approach. Monitoring of antimicrobial use (AMU) is an important source of information that together with surveillance of AMR can be used for the assessment and management of risks related to AMR. In the framework of the Global Action Plan on AMR, the OIE has built a global database on antimicrobial agents intended for use in animals, supported by the Tripartite (World Health Organization (WHO), Food and Agriculture Organization of the United Nations (FAO) and OIE) collaboration. The OIE launched its first annual data collection in 2015 and published the Report in 2016. The second Report, published in 2017, introduced a new methodology to report quantitative data in the context of relevant animal populations, and included for the first time an annual analysis of antimicrobial quantities adjusted for animal biomass on a global and regional level. A continuing annual increase of countries participating in the data collection demonstrates the countries engagement for the global development of monitoring and surveillance systems in line with OIE international standards. Where countries are not yet able to contribute their quantitative data, their reports also highlight the barriers that impede them in data collection, analysis and/or reporting. The OIE Reports show annual global and regional estimates of antimicrobial agents intended for use in animals adjusted for animal biomass, as represented by the quantitative data reported by countries to the OIE. The OIE advises caution in interpretation of estimates made in the first few years of reporting recognizing some important limitations faced by countries as they develop their monitoring systems. The OIE remains strongly committed to supporting its Members in developing robust and transparent measurement and reporting mechanisms for AMU.

Antimicrobial resistance and the use of antimicrobial agents in veterinary medicine are complex issues that are currently a source of major international concern. It is therefore essential for the World Organisation for Animal Health (OIE) to consider this issue, while at the same time continuing to address the problem of zoonotic diseases. That is why the OIE has included objectives for veterinary drugs, especially antimicrobials, in its Strategic Plan. The OIE plays an active part in discussions on this subject in conjunction with other international organisations working in this field, such as the Food and Agriculture Organization of the United Nations (FAO) and the World Health Organization (WHO). Furthermore, the OIE has adopted guidelines both for defining harmonised methodologies for antimicrobial resistance surveillance and monitoring and for helping countries to conduct a risk analysis tailored to their situation and to take appropriate management measures. The OIE has included this issue in its programme of assistance to countries by offering them structural enhancement tools: the Tool for the Evaluation of Performance of Veterinary Services (O1E PVS Tool), PVS Gap Analysis, veterinary legislation support, and training for veterinary national focal points, with the aid of its Collaborating Centres for veterinary medicinal products. Only by mobilising all countries to improve the quality of antimicrobials, to introduce antimicrobial resistance surveillance and to implement measures for the responsible and prudent use of antimicrobials, will it be possible to halt the spread of antimicrobial resistance.

To effectively reduce health risks at the animal-human-ecosystems interface, a One Health strategy is crucially important to create strong national and regional animal health systems that are well coordinated with strong public health systems. Animal diseases, particularly those caused by new and emerging zoonotic pathogens, must be effectively controlled at their source to reduce their potentially devastating impact upon both animal and human health. As the international organisation responsible for developing standards, guidelines and recommendations for animal health, the World Organisation for Animal Health (OIE) plays an important role in minimising animal and public health risks attributable to zoonoses and other animal diseases, which can have severe consequences for global food safety and security. National Veterinary Services, which implement OIE animal health and welfare standards and other measures, are the first line of defence against these diseases, and must have the capacity to meet the core requirements necessary for their diagnosis and control. The OIE works collaboratively with the World Health Organization and Food and Agriculture Organization of the United Nations to improve the ability of national animal and public health systems to respond to current and emerging animal health risks with public health consequences. In addition to improving and aligning national laboratory capacities in high-risk areas, the OIE collaborates on One Health-oriented projects for key diseases, establishing model frameworks which can be applied to manage other existing and emerging priority diseases. This article reviews the role and activities of the OIE in strengthening the national Veterinary Services of its Member Countries for a more effective and sustainable One Health collaboration.

The Biological Standards Commission of the World Organisation for Animal Health (OIE) oversees the preparation and validation of OIE-approved International Reference Standards for use in serological assays for detecting infectious diseases of animals or the adequacy of their immune response following vaccination against those diseases. The principal use of OIE-approved International Reference Standards is to harmonise serological testing and to promote the mutual recognition of test results for international trade. In the OIE Manual of Diagnostic Tests and Vaccines for Terrestrial Animals, the organisation recommends the use of the OIE anti-rabies positive reference serum of dog origin to titrate serum samples in international units (IU)/ml for use in rabies serological tests. The first batch of OIE reference serum of dog origin was produced in1991 and was used internationally until the beginning of 2010. The preparation of the new batch began in 2012 and, in contrast to the previous batch, three commercial inactivated rabies vaccines based on the most frequently used vaccine strains (Pasteur Virus and Flury Low Egg Passage) were selected for the immunisation of dogs in accordance with OIE guidelines. In 2013, calibration was completed through an inter-laboratory test involving five OIE Reference Laboratories for Rabies with the Second World Health Organization (WHO) International Standard for Anti-Rabies Immunoglobulin being used as a reference standard in this calibration. After statistical analysis of the results, the consensus titre was established as 5.59 IU/ml. The technical and statistical data were submitted to the OIE for assessment. In February 2014, the OIE Biological Standards Commission adopted this serum as an OIE-approved standard reagent for rabies serology.

Cross-sectoral assessment of health risks arising or existing at the human-animal interface is crucial to identifying and implementing effective national disease control measures. This requires availability of information from 4 functional information 'streams' - epidemiological, laboratory, animal, and human health. The Food and Agriculture Organization of the United Nations (FAO)/ World Organisation for Animal Health (OIE)/ World Health Organization (WHO) Four-Way Linking (4WL) project promotes the establishing of a national-level joint framework for data sharing, risk assessment, and risk communication, in order to both improve communications within and among governmental public health and animal health influenza laboratories, epidemiology offices, national partners, with the aim of strengthening the national capacity to detect, report and assess risks arising from emerging influenza viruses. The project is currently being implemented in countries where H5N1 avian influenza is endemic and where human cases have been reported. The project is comprised of two main activities at country level: a 'review mission', which is the project launch in the country and has the objective to assess the existing situation; and a 'scenario based workshop', with the scope to bring together key national partners and build relationships among people working in the 4 information streams and to improve understanding of national strengths and gaps. During the workshop the delegates engaged in interactive sessions on basic risk assessment and devoted to specify the needs and roles of the 4 different streams. The participants work through a mock influenza outbreak scenario, which practically illustrates how risk assessment and communication of an emergency at the animal-human interface is more effective when there is linking of the 4 streams, collaboration, communication, and coordinated action. In 2010, Egypt was the first country where the project was successfully implemented, followed by Vietnam and Indonesia.

The ability to minimise the harmful impact of biological threats relies on our capacity to rapidly detect unusual events, including the accidental or deliberate release of pathogenic or toxic agents, and immediately implement control measures. The development of this capacity for each country is the aim of the International Health Regulations (IHR) (2005), a legally binding document adopted by 196 States Parties, including all Member States of the World Health Organization (WHO). Each country's animal health sector contributes to the implementation of the IHR through surveillance, disease reporting and its response to zoonotic diseases, foodborne diseases and other events that emerge at the interface between human and animal health. The World Organisation for Animal Health (OIE) Performance of Veterinary Services (PVS) Pathway allows countries to undertake a comprehensive evaluation of their Veterinary Services and identify areas that need improvement. The OIE and WHO have conducted an in-depth analysis of the differences and synergies between the tools used by WHO to monitor the implementation of the IHR and the OIE PVS Pathway, revealing a wide range of similarities, complementarities and synergies. Taking advantage of the outcomes and outputs from the assessment and gap analysis tools used in the IHR Monitoring Framework and the OIE PVS Pathway, and exploiting the strength of these institutional frameworks, WHO and the OIE have jointly developed methods to facilitate communication between the animal health and human health sectors. This enhanced dialogue improves operational coordination and more efficiently informs policy-makers on strategic investments to strengthen their preparedness for controlling the spread of zoonotic diseases.

One of the main objectives of the World Organisation for Animal Health (OIE) is to ensure transparency in and knowledge of the world animal health situation. To achieve this objective, the OIE relies on its network of Member Countries, which is complemented by the activities of 221 Reference Laboratories (RLs) and Collaborating Centres. The RL mandate states that, in the case of positive results for diseases notifiable to the OIE, the laboratory should inform the OIE Delegate of the Member Country from which the samples originated and send a copy of the information to OIE Headquarters. However, since 2006 the OIE has received a lower than expected number of notifications from RLs, which implies eitherthat the majority of samples are sent to national laboratories or that some RLs are not fully complying with their mandate. The OIE sent a questionnaire to RLs in preparation for the Second Global Conference of OIE Reference Laboratories and Collaborating Centres (Paris, France, 21-23 June 2010). Two main factors emerged: the need for RLs to clarify their role and responsibilities in disease reporting and the need for an awareness campaign to sensitise national Veterinary Services to the importance of conducting more surveillance (and consequently of submitting samples to RLs) for all OIE-listed diseases. Reference laboratories indicated two main reasons for not sharing more data on positive samples with the OIE: i) a perceived contradiction between their mandate as OIE RLs and the standards of the International Organization for Standardization (ISO) dealing with confidentiality; and ii) certain Member Countries or stakeholders asking RLs not to share positive results with the OIE, for political or economic reasons. The OIE has put forward proposals to help RLs resolve these problems in future. The use of ISO standards must be clarified and there must be improved communication between the OIE and its RLs. A lack of transparency about a significant disease event can jeopardise the biosecurity of several countries, an entire region or even the whole world. The reference status of a non-transparent RL could be questioned.

Equine influenza is an acute contagious respiratory disease of horses worldwide caused by infection with equine influenza A virus. Current epidemiological surveillance suggests that equine influenza A virus strains of the H3N8 subtype (i.e. influenza A/equine 2 virus) are the major causative virus strains. It is known that antigenic drift occurs in the gene coding for the haemagglutinin protein of equine influenza A virus strains. This drift eventually leads to the circulation in the equine population of influenza virus strains that are antigenically heterologous to those used to produce the antigenic fraction of authorised equine influenza vaccines, thus compromising vaccine efficacy. An Expert Surveillance Panel, including representatives from the World Health Organization and the World Organisation for Animal Health (OIE) reference laboratories, annually review the epidemiological and virological information on equine influenza. Based on this review, the OIE Expert Surveillance Panel on Equine Influenza Vaccine Composition publishes, on an annual basis, recommendations on suitable viral strains to use in the manufacture of the antigenic fraction of equine influenza vaccines in order that they are protective against circulating equine influenza virus strains. On the basis of this annual review, it is expected that modifications to the equine influenza virus strains used to manufacture the antigenic fraction of authorised vaccines will be necessary on a regular basis. However, to date, no equine influenza vaccines authorised for use in the UK have been updated fully in line with the latest OIE recommendations and experience indicates that several years of development are required to establish new viral master seeds and generate the data needed to support a change to the respective Marketing Authorisations (MAs) to incorporate a new strain. In this article I will discuss the regulatory framework that applies to veterinary vaccines and the constraints that mean that addition or substitution of a vaccine strain is not a trivial task. In the EU it is illegal to market a veterinary medicinal product (VMP) unless an MA has been granted by the relevant competent authority. Veterinary medicinal products can either be authorised by a European centralised procedure managed by the European Medicines Agency, in accordance with Commission Regulation (EC) 726/2004 1, or nationally by individual member states, in accordance with Directive 2001/82/EC 2. In the case of centralised procedures, if approved the MA is issued by the European Commission and is valid throughout the EU. The Veterinary Medicines Directorate is responsible for authorisation of VMPs in the UK. There are also procedures for EU member states to mutually recognise products that are nationally authorised in other EU member states and also for coordinated assessment of new national applications. Irrespective of the authorisation route, the time allowed for regulatory authorities to assess applications for new products is specified in EU legislation as 210 days, although the total time from application to authorisation can be longer depending on the time taken for the applicant to respond to any requests for additional information. When a product is authorised, details of the approved indications, known adverse reactions and conditions of use are published in the Summary of Product Characteristics (SPC), which is used by the manufacturing authorisation holder as the basis for the information included on the labels and the product leaflet. The vaccination scheme described in the SPC is the one that has been supported by the data included in the application dossier and must be regarded as unique to the specific vaccine. Some equestrian organisations such as the British Horse Association and Fédération Equestre Internationale prescribe specific vaccination schedules for horses entering their competitions. If these schedules are not in line with the SPCs of the vaccines used, then they would have to be considered as off-label use, and therefore the responsibility of the prescribing veterinarian, because they are not supported by the data submitted by the MA holder. Irrespective of the route of authorisation, the basic data requirements for authorisation of vaccines against equine influenza are indicated in European Pharmacopoeia (Ph. Eur.) 3 monograph 0249 (Equine influenza vaccine [inactivated]). In addition to use of good quality ingredients this requires demonstration of safety for horses under the intended conditions of use and demonstration of protection against challenge for at least one of the strains included in the vaccine. To minimise the use of experimental animals, if one of the strains has been shown to protect against challenge then serological responses can be used to confirm the efficacy of other strains included in the vaccine. It is important to note that the only efficacy requirements of Ph. Eur. monograph 0249 are that 'the claims for the product reflect the type of immunogenicity demonstrated (protection against challenge or antibody production)' and that 'the vaccine complies with the test if the vaccinated horses show no more than slight signs; the controls show characteristic signs. The average number of days on which virus is excreted and the respective virus titres are significantly lower in vaccinated horses than in control horses'. There is no absolute requirement for a specific percentage level of protection or a prevention of virus excretion. From a regulatory perspective, a decision to authorise a veterinary medicinal product is made on the basis of a positive benefit:risk assessment, which is based on the safety and efficacy information provided in the application dossier. A clinically relevant degree of efficacy and compliance with the Ph. Eur. monograph need to be demonstrated but it is important to recognise that authorised vaccines can only be expected to confer the level of efficacy indicated in the SPC, which is based on data submitted by the applicant. Shedding of influenza virus from vaccinated horses is often considered by clinicians as 'vaccine breakdown'. However, none of the equine influenza vaccines currently authorised in the UK is claimed to prevent viral shedding, only to reduce viral shedding. In this sense, isolation of influenza virus from horses vaccinated according to the SPC does not necessarily imply a lack of efficacy in the terms of the authorisation. In the French outbreaks described in the report by Legrand and colleagues in the current issue, equine influenza was detected in both vaccinated and unvaccinated horses but the vaccinated horses had a lower prevalence of fever 4. Updating of influenza virus strains in authorised equine influenza vaccines requires a variation application. The procedures for variation applications through the centralised or mutual recognition routes are laid down in Commission Regulation (EC) 1234/2008 5. Although this regulation originally did not apply to products that are authorised only nationally, its scope is being extended to encompass nationally authorised products by Directive 2009/53/EC 6. Thus the procedures to vary veterinary vaccines authorised by any of the various routes are effectively harmonised within the EU. The regulation includes special provisions for variations concerning the replacement of a strain in a veterinary vaccine against equine influenza. The timeline for initial assessment of such an application is specified as 90 days and the overall time taken is typically 3–8 months depending on whether additional information is needed and how long it takes the applicant to provide that information. To facilitate the replacement or addition of strains to already authorised vaccines the Committee for Medicinal Products for Veterinary Use Immunologicals Working Party has recently developed a guideline on the data required to support such variations (Guideline on the Compliance of Authorised Equine Influenza Vaccines with OIE Requirements, EMA/CVMP/IWP/97961/2013 QDraft 7), which has been released for consultation. This guideline is intended to replace the previous Note for Guidance: (Harmonisation of Requirements for Equine Influenza Vaccines – Specific Requirements for Substitution or Addition of a Strain or Strains, EMEA/CVMP/112/98-FINAL 8), which did not allow for the type of changes that vaccine manufacturers need to make to their vaccines in order to comply with the latest OIE recommendations. It should be noted that regulatory authorities can only respond when companies apply to update the virus strains in their vaccines. Although they can recommend such changes, they have no power to compel vaccine manufacturers to update their vaccines when OIE recommendations change. How long it takes for such recommendations to be adopted therefore depends mainly on the time needed for vaccine manufacturers to generate the required supporting data. Although the OIE publishes recommendations for virus strains to be included in vaccines on an annual basis, regulatory authorities are unable to compel vaccine manufacturers to make changes to their products unless significant safety concerns have been identified. After authorisation, the performance of veterinary medicines in the field is monitored by pharmacovigilance. In the UK, reports of adverse reactions or suspected lack of efficacy are sent to the Veterinary Medicines Directorate and in the event of a significant number of reports of suspected lack of efficacy this would be discussed with the manufacturers. However, any decision to change the strains would be made by the company on commercial grounds. The strain recommendations made by the OIE are to provide for the closest match between vaccine strains and the strains circulating in the field. However, inclusion of different strains in the vaccine does not necessarily mean that the vaccine will not be efficacious because a degree of cross-protection can be expected. In this context it may be relevant that, in contrast to most human influenza vaccines, most equine influenza vaccine contain adjuvants to potentiate the immune response. It may therefore in practice only be necessary to actually change the vaccines when they are no longer efficacious. In consideration of the time needed to generate the data needed to support a change of strain, as an interim measure, in some cases vaccine manufacturers have chosen to demonstrate that their existing vaccine formulation provides protection against newer circulating strains. A variation application is still required to include such a claim in the SPC and on the labels for the product but since new quality and safety data are not required the overall time for this can be much reduced compared with strain substitution. The draft guideline EMA/CVMP/IWP/97961/2013 7 also gives guidance on the type of data that would be needed to support such a variation. It is suggested that, if a correlation between antibody titre and protection against the newly circulating strain has been demonstrated, then serological responses may be used to demonstrate efficacy, otherwise protection against challenge with the newly circulating strain will need to be demonstrated.

The swine flu pandemic plagued Mexico in March 2009, which spread all over the world rapidly. The World Health Organization (WHO) initially called it as “swine flu”. On Apr. 30, 2009, WHO, United Nations Food and Agriculture Organization (UNFAO) and World Organization for Animal Health reached an agreement to replace “swine flu” with influenza A (H1N1) [1, 2].