Eradicating bovine TB: could vaccinations be the answer?

As the pilot badger culls in Somerset and Gloucestershire are set to begin imminently, controversy has once again arisen this week over the best approach for limiting the spread of bovine tuberculosis (bTB). Vaccinations of both cattle and badgers have received increasing attention as an additional method to use in limiting the spread of bTB but as yet the extent of how they can help is not fully known. Yesterday, a report by the Environment, Food and Rural Affairs committee (EFRA) was released to detail current vaccination research and deliver advice over the shortcomings of current research and government approaches.

Since 1994, the government has spent over £35 million in bTB vaccination research, and plans to spend a further £20 million in the next five years. Vaccinations are being developed for both cattle and badgers, yet face many problems to overcome. Cattle vaccination requires a change in EU legislation, as the current Bacille Calmette Guérin (BCG) cattle vaccine interferes with skin tests used to determine between uninfected and infected cattle. The recent development of a ‘DIVA’ test (Differentiating Infected from Vaccinated Animals) to use alongside the BCG vaccine has been hailed as a positive step in furthering the possibility of vaccinating cattle. However, the protection such a vaccine provides is variable, and extensive field tests of the vaccine and ‘DIVA’ test are required before EU laws can be changed. Vaccinations for badgers have been available since March 2010, yet due to financial problems and determining the best way to administer the vaccine has limited their current use. Work into whether vaccines can be given orally is ongoing.

Reviewing this research, the EFRA committee have declared that vaccinations do have a part to play in resolving the bTB crisis, and welcome the ongoing work that is being done in this area. However, used alone they are not a miracle cure, and in their words is not a ‘magic bullet’. This is for many reasons, most prominently because vaccinations are expensive to deploy, are variable in the protection they offer to uninfected animals (and for infected animals they give no protection) and have limited effect in the short term. Therefore, vaccinations should be used as part of a wider solution to tackle bTB.

However, whilst the research itself has been relatively successful, the EFRA committee argues that the way the government has developed and subsequently communicated this research has been deficient. In particular, several shortcomings were highlighted:

• A lack of clear communication with the public has led to widespread misunderstanding concerning if, how and when vaccinations of cattle and/or badgers could be introduced;
• There has been slow progress of the government working with the EU commission regarding how EU laws can be altered to allow cattle vaccination within the UK;
• Field trials of the ‘DIVA’ test were postponed as the government argued that legislation had to change first, which was untrue, slowing development of a cattle vaccination;
• Cancellation by the government of five out of six badger vaccination deployment projects, as part of research into badger vaccination, reflects a missed research opportunity;
• A lack of a clear timeline and strategy has slowed research and therefore subsequent development of when vaccinations will be available to use is uncertain.

The EFRA committee claim that such shortcomings have seriously damaged the impact research surrounding vaccinations has had, leading to confusion and uncertainty into how vaccinations could help with bTB. In particular, the report criticises the poor communication and clarity of evidence that the government has used to inform the wider public. Given the huge controversy that surrounds bTB, shortcomings such as these is detrimental and could seriously have affected how MPs, scientists and the public alike developed their opinions around such research. This is certainly a case of where poor science communication can have significant implications.

Into the future, vaccination research is still to progress and future developments will hopefully aid in tackling bTB. The EFRA committee urge that a timeline and clear strategy for such research should be developed and stuck to in order to get vaccinations used in field studies and later in farms and more badger populations. It also suggests that the government needs to move from being reactive in its research approaches to being more proactive; this should happen if a clearer timeline is produced. Most importantly perhaps is the need to communicate such research in a transparent and unbiased way in order to allow the public to make opinions developed from scientific evidence rather than misinformed facts and figures.