News that a girl in Ecuador has become seriously ill with the bird flu virus has added to concerns about the outbreak. What is the size of the risk and why is there no vaccination?
Avian influenza has been a major problem for decades: the virus spreads around the world in waves and causes, over one year, mass deaths among migratory birds, birds from hobby farmers, and among birds in large poultry farms. The current pandemic began as early as October 2021, when the confinement order went into effect after increased reports from abroad of local bird flu outbreaks.
The European Center for Disease Prevention and Control now classifies this outbreak as the largest ever in Europe and, moreover, an outbreak that will continue for a long time. Previously, outbreaks more or less kept pace with seasons and bird migration. Once the large flows of migratory birds ended, the virus became extinct again. But virologists now see that the virus has spread so widely that there wasn’t any breathing space between those periods and the virus could circulate year-round. Climate change may play a supporting role in this: as the migration routes and patterns of birds change, the spread of the virus may also be different.
As it is now known from Corona, avian influenza also manifests itself in cascading forms. They are classified as low pathogenic, which does not make animals sick, or highly pathogenic, which makes animals seriously ill. In both cases, poultry farms are disinfected. The current H5N1 variant is highly pathogenic. It is spread worldwide by wild birds, but may have originated among domestic birds in China.
danger to people
News of the spread of the avian influenza virus in Ecuador to humans made headlines around the world. However, it is not unique for a person to become infected through contact with a bird. During each outbreak, cases are reported of people who had direct contact with poultry and became infected, such as farmers and veterinarians.
It was exceptional and alarming that the nine-year-old girl became so ill with the infection that she had to go into intensive care. This does not happen often. In the Netherlands, a veterinarian died in 2003 of pneumonia, which may have been the result of infection with the avian influenza virus.
These cases are evidence that jumping from animals to humans is possible and therefore vigilance is required. But there are also reassuring facts: to begin with, the number of cases is nothing compared to the number of infected animals: it is a very exceptional phenomenon and it still is. Second, human-to-animal contamination does not mean that people also infect each other with avian influenza. A few cases have been reported in the past, but these are also very high exceptions.
Damage to the poultry and animal sector
Currently, the damage mainly concerns wild populations of birds and poultry. Anyone who visited Dutch beaches last summer could not miss the huge number of dead birds lying in the sand: seagulls, gannets, sandpipers. The virus causes a fight between wild (migratory) birds.
Poultry farmers have been suffering from infection among chickens, turkeys and geese since the end of 2021. The Dutch Food and Consumer Safety Authority reports that since October 2021, more than a hundred outbreaks have already been counted in the Netherlands, not even reports from sites with fewer than fifty animals. Nearly 6 million animals have been culled or killed and destroyed.
Of these, 4.7 million animals were culled on farms where bird flu had already been detected, and another 1.1 million animals on farms close to infection sites. Disposal costs can easily reach €100,000 per company, which is paid from a fund half filled by the sector and the other half by the government. But since the pot is already empty, the government will bear all the more than 30 million, Omroep Brabant reported.
Why is there no universal vaccination?
It seems that the solution is at hand, because there are vaccines against bird flu. But unfortunately, there are also plenty of barriers that prevent vaccination, especially in the short term, from offering any solace.
First of all, decades ago, a course was already set in a European context that was not specifically aimed at vaccination as a solution. This was the result of different scientific insights in the veterinary field. Avian influenza outbreak policy consists and continues to consist of surveillance, preventive measures and rapid intervention if something goes wrong somewhere.
There is also something to be said for that. For a long time it was not possible to distinguish between a vaccinated chicken and a chicken infected with the virus. This made vaccinated chickens worthless for export. Many countries are relentlessly closing the door on fortified meat. Germany does not even want fertilized chicken eggs, even though there is no apparent public health risk. On the other hand, many countries prohibit the import of poultry from an area where there is an outbreak of bird flu anyway.
The European Union is stuck in a no-vaccination policy
There is a movement in the EU’s no-vaccination policy. In many countries, insemination of birds and poultry is now done for commercial purposes, with the agreement that other countries may not reject the products of those poultry. But these are small experiments. There is still a trade ban in the European Union on poultry products vaccinated against avian influenza.
It is an illusion to obtain definitive protection even with mass vaccination, because it is simply impossible to vaccinate wild birds. As a result, different types of bird flu will continue to circulate around the world. But at least it will protect poultry and hobby animals.
Does technology offer a solution?
There is progress in the technical field. Various objections to vaccination are removed. For example, vaccines are now equipped with a kind of marker that makes it possible to clearly distinguish between vaccinated and infected animals. In addition, vaccination can become less labor-intensive and expensive by administering vaccines in a powder form that can be mixed into feed rather than by injection. But vaccine manufacturers are reluctant to research and develop these vaccines because it is not clear if there is a market for them.
The question is whether EU member states will adopt preventive vaccination. From an animal-friendly point of view, the Left and Green parties see the problem more in the way the poultry sector operates, with large numbers of birds crowded together. They would rather see an end to intensive poultry farming than keep the sector afloat with technological palliatives. Influential virologist Thijs Kuiken of Erasmus MC discusses a powerful combination of measures, including vaccination and close surveillance, but also reducing the density of poultry farms in the Netherlands by buying up companies.