The World Health Organization has already raised concerns about the alarming spread of a strain of the bird flu virus and next weekend an international survey will be released which reveals that scientists believe this viral agent will be the cause of a new pandemic. Pulmonologist Filipe Froes, who coordinated the Covid office of the Medical Association, explains what this virus is and admits that one must “be prepared for the worst”
What exactly is Bird Flu?
There are several types and strains of the influenza virus, the virus responsible for the flu. Some of these strains infect humans (human flu) and other strains infect other animals, particularly birds (avian or bird flu). There is relative species specificity as a result of the existence of specific receptors for each species. Humans predominantly have a different type of receptor in the cells of the respiratory system than birds, but some animals, for example pigs, share these two types of receptors.
Do viruses always cause the same disease?
Avian flu viruses can cause different types of illness in birds. The avian viral strains associated with the most serious disease are called Highly Pathogenic Avian Influenza Virus (HPAIV), which translates to Highly Pathogenic Avian Influenza Virus
How is Bird Flu transmitted?
Bird flu is predominantly transmitted in the same way as human flu, that is, by air. The air route allows effective transmission between animals of the same and different species.
Scientists say it will be the cause of the next pandemic. Is it a certainty?
HPAIV are one of the biggest threats to future pandemics, which requires permanent monitoring. Human cases with HPAIV have been described for more than 30 years. The most famous occurred in Hong Kong, in 1997, due to an H5N1 subtype and led to the mass slaughter of more than 1.5 million birds.
For a pandemic to occur, three factors must be combined:
- the emergence in the human population of a new virus to which the majority of the population has never had contact and there is no immunity
- effective transmission between humans, which requires the ability to effectively bind to human cell receptors
- ability to cause potentially serious illness
And are these factors already combined?
HPAIV are currently new viruses to humans and have the potential to cause serious illness. The only thing missing is effective transmission, which can occur at any time.
Is there any idea when that might be?
It can happen at any time, so we must maintain constant vigilance and always be prepared. As they say, it usually happens when you least expect it.
Are there fears that it could evolve into a different, more dangerous virus?
The precautionary principle that guides preparation is always the same: “Prepare for the worst, hope for the best”. Because when we are more prepared, everything goes better.
There are some recent signs that should alert us to an increased pandemic risk with the diagnosis of HPAIV cases in mammals, particularly in cows.
Is the virus similar to the one that causes Covid or does it have completely different characteristics?
The only similarity with the SARS-CoV-2 virus is the transmission route. All other characteristics, such as the most affected population groups and severity, will be discovered throughout the infection. This is one of the justifications for being prepared for everything and, necessarily, for the worst.
What can be done to prevent the worst?
The pandemic that ended last year taught us the preventive usefulness of non-pharmacological intervention measures, namely, the face mask, respiratory etiquette, hand hygiene and physical distancing. These measures allow us to buy time for the development of a vaccine.
Are there vaccines? Or some under investigation?
In relation to HPAIV, several vaccine prototypes have already been developed, with some production and safety tests already carried out. When it is known which strain is responsible for the pandemic, it will only be necessary to include the new antigens in the vaccine prototypes already developed. Fortunately, in the case of HPAIV, flu medications (for example, oseltamivir and zanamivir) have remained effective.
What is Portugal doing to deal with the issue?
Our country is included in European and global surveillance networks, also benefiting from the sharing of decisions within the EU. If there is one lesson that we can and should implement, it is to maintain strategic reserve networks and increase our autonomy in terms of manufacturing personal protective equipment, antimicrobial drugs and, ideally, vaccines.
What is the biggest concern of the scientific community right now?
The two biggest concerns are always the same: devaluation and misinformation. Devaluation causes delays in preparation and response and misinformation, often associated with ignorance, undermines confidence in science, knowledge and the response of official bodies. We must never forget that pandemics are a test of our ability to live in community.
