Avian influenza may not pose an immediate threat to humans, but pharmaceutical manufacturers and researchers are leveraging the COVID-19 experience to get a step ahead
As we discussed in an earlier article, governments are responding to the largest avian flu epidemic in recent years by considering a reversal of the ban on vaccinating poultry against the virus. Now there is growing concern about the potential for avian influenza to cause a serious outbreak among humans, and while the risk of infection is still relatively low, experts agree that the potential consequences of an outbreak are significant.
Avian influenza primarily affects birds. Recently, minks in Spain, seals in Scotland, sea lions and dolphins in South America and a number of mammal species have been found to be infected with H5N1, a highly pathogenic strain of avian influenza.
While avian flu is not new - epidemiologists have been studying it for decades - the detection of the virus in mammals is a reminder that some strains of the virus can also infect humans, and in some cases the infection can be severe and even fatal. In particular, the H5N1 strain of avian influenza has been associated with a high mortality rate in humans, and there are concerns that other strains could also pose a significant risk.
In birds, the avian influenza virus attaches to a receptor in their respiratory tract. For the virus to start circulating from person to person it would have to evolve to attach itself to the human version of this receptor—something it hasn’t yet done.
So while many believe this is an animal health issue that has only a theoretical risk of becoming a human health issue, there has been a concerted effort to develop effective human vaccines to protect against avian influenza with many companies and governments re-evaluating their thinking on getting people vaccinated.
Sanofi Pasteur is one company that has been actively researching and developing vaccines against avian influenza. Their most recent vaccine, QIV (Quadrivalent Influenza Vaccine), is designed to provide increased protection against H5N1 and provides active immunisation against four influenza virus strains (two A subtypes and two B types) contained in the vaccine.
Other companies that are working on avian influenza vaccines include GlaxoSmithKline, Novartis, and Seqirus (which has developed a pandemic preparedness vaccine AUDENZ, targetting the H5N1 subtype specifically, and is approved by the Food and Drug Administration). These companies are all investing significant resources into developing effective vaccines that can help protect people against the potential risks of avian influenza.
There are also efforts to apply messenger RNA (mRNA) technology—such as that used for some of the COVID vaccines—to avian flu vaccines. Once the genetic sequence of a new variant is known, RNA vaccines can be quickly designed and tested in animal models. And because of the COVID pandemic there is now a well-developed infrastructure for mass-production of doses. It is this speed of production and ability to target specific emerging variants that give an advantage to this technology.
Governments are also responding to calls for increased vaccination in human populations. For example, in the United States, the Centers for Disease Control and Prevention (CDC) recommends that certain groups of people receive vaccination against avian influenza. These groups include healthcare workers, people who work with poultry, and anyone who may be exposed to infected birds or contaminated environments.
Similarly, in the United Kingdom, the government has implemented a national avian influenza vaccination program for people who work in the poultry industry. This program is designed to protect workers who may be at increased risk of exposure to the virus.
Overall, there is a growing consensus among experts that vaccination against avian influenza is an important step in protecting people against the potential risks of this virus. While the risk of infection is still relatively low, the potential consequences of an outbreak are significant, and the development of effective vaccines is an important step in reducing this risk.
Hoeford Research has its roots in the welfare of animals and vaccines for the poultry industry. We support vaccine development and vaccination programmes and believe they have a significant role to play in mitigating the damaging effect of avian influenza.