- This new strain of bird flu is, in fact, a mixture of three different types of bird flu variants
- There’s a greater risk that this strain could acquire the ability to spread more easily from person to person
- We really need are potent antiviral medicines with broad activity against many different strains of pandemic virus
In Asia, more than 120 people have been sickened, and 23 are dead, from a potent strain of bird flu that has the frightening markings of a potential pandemic strain.
We have grappled with deadly pockets of potent flu outbreaks before. But this one has characteristics that make it different.
There’s a greater risk that this strain could acquire the ability to spread more easily from person to person. If it does, it could have devastating consequences.
That’s because we may not be ready. We have the capacity to make a vaccine. But we may not have the time. What we need are oral drugs that can combat a wide range of different pandemic flu strains. For the most part, we don’t have these medicines.
The number of confirmed H7N9 bird flu cases in Mainland China increased by five on Sunday, the country’s official Xinhua news agency reported. Four provinces — Zhejiang, Shandong, Jiangxi and Fujian — reported illnesses.
Like other strains of bird flu, this H7N9 virus affects mostly poultry – and has spread mostly to people handling chickens.
The Chinese Government suspects that there have already been human-to-human cases – proof that the virus has developed the capacity to spread by people. Of the patients analyzed so far, half appear to have had no contact whatsoever with poultry. Officials from the World Health Organization have confirmed that this new strain transmits to humans more easily than previous bird flues. American health authorities have confirmed the human spread.
Moreover, a case has already been reported outside China — an equally worrisome development.
Another problem is the absence of visible illness in poultry infected with the new virus. This makes it harder to track the spread of the disease, and to eradicate its source by slaughtering stricken birds.
Right now, 18 percent of the cases in China have ended in death. This is less deadly than the previous avian flu outbreak in China six years ago (that H5N1 bird flu virus killed more than 300 people after spreading from China to other countries in 2006). But this new strain has characteristics that make it perhaps more problematic.
One flu expert, John Oxford from Queen Mary University in London, told Reuters this week that this new strain of bird flu is “very, very unsettling.” It’s, in fact, a mixture of three different types of bird flu variants and “seems to have been quietly spreading in chickens without anyone knowing about it,” he said.
As Reuter’s noted, recent pandemic viruses, including the H1N1 “swine flu” that spread through the United States in 2009 and 2010, have been mixtures of mammal and bird flu. These kinds of hybrids are more likely to be milder because mammalian flu tends to make people less severely ill than bird flu.
By contrast, pure bird flu strains, such as the new H7N9 virus that’s now spreading in China, are generally more deadly for people.
So are we ready to battle a pandemic strain of bird flu if this new virus picks up the capacity to more efficiently spread from person to person?
For the most part, our strategy for preparing for pandemic flu focuses on the development of vaccines. We’ve made a lot of strides in recent years developing the tools and infrastructure for rapidly developing just such vaccines.
Moreover, countries where these viruses often get their start (in Asia) have become much more aggressive and transparent at combating early outbreaks.
Our tools for surveillance and quarantine in the U.S. have also gotten a lot better.
But there’s good reason to believe this may not be enough.
What we really need are potent antiviral medicines with broad activity against many different strains of pandemic virus. These drugs could be used not only to treat infected patients, but as a prophylaxis in those who might be exposed to the bug.
In the event of a full-blown outbreak of pandemic flu, there may not be enough time or capacity to develop an effective vaccine and to deliver it.
Antiviral drugs can also be effective at containing early outbreaks, before they become a full-blown pandemic.
Moreover, we may not know that a strain has turned into a pandemic until its too late to scale up vaccine production, which can take six months or longer if we have trouble getting a viral seed stock to use in that process.
Finally, the government may be skittish at undertaking a costly, crash program to develop a vaccine until a pandemic is already manifested.
The Feds got a spate of criticism for their expensive effort to rapidly develop a vaccine to the H1N1 swine flu strain the rippled through the country in 2009 – a government effort that by most reasonable measures was not only prudent, but successful. Yet the political fallout from that episode could make public officials skittish next time, giving the virus a dangerous chance to get the jump on us.
The mix of programs that we have put in place over the last decade to combat a potential pandemic has generally underinvested in developing oral antiviral drugs. Yet there are a number of promising drugs already on the shelf, and with adequate investment, it seems likely more could be developed.
An adequate vaccine is an important tool. But it may not be enough — or come in time. We have given comparatively short shrift to developing an oral antiviral with broad applicability to a range of pandemic strains. Yet we need one on our shelf if we’re going to be ready for this bird flu outbreak, or a future one.