The current strain of highly pathogenic avian influenza, commonly generally known as bird flu, has turn into a worldwide problem. The virus has infected. Several million Of birds, something else Animal speciesand a Small number of people.
Last week, Australian Govt issued a warning Residents traveling to Europe, North America, South America and Asia in regards to the risk of bird flu.
Warning, published on Smartraveller websiteIncludes advice on ensuring your flu vaccine is up so far. If you're going to travel, that sometimes means if you happen to've had the flu this yr, although it's best to check together with your doctor if it's been 3-6 months since your vaccine. We should talk.
But the seasonal flu vaccine we get yearly doesn't actually prevent bird flu in humans. So why is it being advisable on this context?
Some background on bird flu
Smartraveller Note Several strains Bird flu is currently circulating.
The most relevant strain, called 2.3.4.4b cladeemerged a number of years ago from a variety of influenza A (H5, or A/H5) that has been circulating for a long time.
Clade 2.3.4.4b primarily affects birds, including wild birds and poultry. It has had devastating effects on bird populations in addition to farmers and others involved within the poultry industry.
In recent years, clade 2.3.4.4b has been adapted. Some infect mammals.. Unfortunately, it causes serious illness. some animals. Some marine mammals have been particularly hard hit, with mass mortality events. Reported In elephant seals and sea lions. Bird flu has also spread within the United States. Among dairy cows.
Compared to the big variety of animal trials, a comparatively small number have been conducted Humans infected with bird flu. Since 2003, 878 cases A/H5N1 influenza has been reported in humans, with a small proportion reported since 2020. Clade 2.3.4.4b emerged first. Reported cases are individuals who have had close contact with infected animals. It doesn't appear to spread from individual to individual.
Thus, the The risk to passengers is minimal.. There are some situations where the danger could also be higher, akin to for people visiting live markets, or people traveling specifically to work with wildlife or animals in food production.
Infection in humans With H5 influenza, symptoms can vary significantly in severity, from mild conjunctivitis to fatal pneumonia. H5 influenza strains appear. Susceptible to antivirals (oseltamivir, also generally known as Tamiflu) they usually are often Recommended As a treatment for human infections, nevertheless it is Not clear Whether they reduce the danger of death in individuals with severe disease.
To date, one case of A/H5 influenza (not 2.3.4.4b) has been reported. Report in AustraliaIn a toddler who had recently returned from abroad.
While Clade 2.3.4.4b is detected. In all continents Except for AustraliaOther strains of avian influenza (A/H7) It is reported here earlier this yr.
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Seasonal flu vaccines should not effective against bird flu.
Seasonal influenza refers to strains of flu that flow into every year. Since the COVID pandemic, three different strains have circulated in various proportions – influenza A H1N1 (derived from 2009 swine flu strain), influenza A H3N2 (which has In circulation since 1968) and an influenza B strain. Interestingly, one other influenza B strain (Yamagata lineage) has disappeared During the COVID pandemic.
Seasonal influenza vaccines contain the most recent strains (A/H1N1, A/H3N2 and B) which might be advisable by the World Health Organization every year. They are Moderately effectiveReduces the danger of hospitalization by about 40-60%.
Influenza vaccines are quite specific within the protection they supply. For seasonal vaccines, even very small changes within the virus from yr to yr are enough to “escape” vaccine-induced immunity. Hence the seasonal flu vaccine Do not provide any protection. Against A/H5 influenza.
Preventing human stress of hybrid birds
The rationale for recommending flu treatment to travelers within the context of the present bird flu outbreak is that the seasonal flu vaccine may help reduce the danger of co-infection with each A/H5 and seasonal influenza.
When this happens, the genetic code from each viral strains is more likely to “recombine.” It can transmit seasonal human viruses with the intensity of avian influenza viruses. 2009 swine flu strain Born of recombination. Over the years many strains have turn into more transmissible to humans.
Obviously, a simpler vaccine would contain the H5 strain, to induce an immune response specific to the H5 flu strain. Vaccine manufacturers have. H5 vaccine developed. Over the years, but to this present day Finland only H5 vaccine has been administered to a small group of people that work with potentially infected animals.
Currently Risk level The exposure to humans brought on by H5 will not be considered sufficient to warrant a particular vaccine program, because the potential advantages are small in comparison with the prices and potential risks related to any recent vaccine program.
Cost of flu shot for travelers
Seasonal flu vaccines protect against influenza infection, and may reduce the danger of concurrent infection with human and bird flu strains. Bird flu aside, for many travelers who haven't gotten a flu shot this yr, reducing the danger of illness disrupting travel plans must be enough to get one.
For those that have already had a flu shot this season, protection appears after vaccination, as with the COVID jabs. Over time. So if you happen to're traveling to the Northern Hemisphere in the course of the winter months, and it's been greater than 3-6 months because you got the flu vaccine, your doctor may recommend one other one.
Bird flu poses little risk to most travelers, but people will want to take sensible precautions, akin to avoiding close contact with birds in markets.