The World Health Organization fears that bird flu may now spread between humans

The World Health Organization fears that bird flu may now spread between humans

The World Health Organization is "really concerned" that the current avian influenza outbreak may now spread among people for the first time in more than 25 years. So the WHO organization has ordered the production of a new avian influenza vaccine in response to the rapid spread of the H5N1 strain of bird flu that caused the current outbreak.

An 11-year-old girl died of bird flu in Cambodia this week while her father was also infected, and 11 others are under observation, some of whom developed symptoms. Experts worry that the large mass could mean the virus has now evolved to be able to pass from human to human.

While captive and wild birds have been decimated worldwide by the current H5N1 strain, there is no evidence yet that it can be transmitted between mammals.

If the virus can cross the species gap from birds to humans, concern about avian influenza and its potential to cause a pandemic will escalate.

No sustained transmission of avian influenza has occurred, but the limited human-to-human transmission was reported in Hong Kong in 1997.

The outbreak in Cambodia is causing more concern than the isolated cases that have emerged in the past two decades, said Dr. Sylvie Briand, WHO director for epidemic preparedness, epidemics, and prevention.

"When you only have one case, you imagine it's because that case was exposed to animals, whether they're alive or dead. For us, that means it's a zoonotic infection," she said Friday.

But when you see several possible cases surrounding this initial issue, you always wonder what happened. Is it because the initial cases might have transmitted the disease to other humans?

"And so we are concerned about the potential for human-to-human transmission as a result of this initial outbreak from animals.

"This is the ongoing investigation into this girl's contacts in Cambodia. We are first trying to find out if these people have H5N1 infection, so we await laboratory confirmation of those cases.

"Secondly, once we have that confirmation, we will try to understand if these people were exposed to animals or if the initial case contaminated those people."

WHO staff is now on the ground in Cambodia, and these assessments' results will determine the next steps.

"In response to the spread of H5N1 and a bit of evolution," added Dr. Richard Webby, director of the WHO Collaborating Center for Studies on Influenza Ecology in Animals, a new vaccine specifically against the currently dominant strain developed.

"We are putting another H5 vaccine candidate into production, which will start soon," he said.

Dr. Wiebe added that the current stock of virus vaccine candidates — which could be deployed in full vaccine drives if an animal infection proves to have jumped to people — are also being evaluated to see if they work against the current vaccine—the dominant form of avian influenza. "There has been a little bit of work looking at some of the serum collected from people who participated in vaccine trials for some of these earlier parts of H5, and many of those people worked well with some of the more recently circulating viruses," Webby said.

"From a vaccine stock and response standpoint, I think this is encouraging and suggests that the human response to some vaccines stimulates broad immunity that reacts to many of the masses that we see."

Dr. Wenqing Zhang, head of the WHO's global influenza program, added that there are currently nearly 20 H5 vaccines authorized for epidemic use, and the new vaccine will add to this repository.

The WHO announcement comes after the UKHSA commissioned Covid-like modeling of avian influenza if the person-to-person transmission was present in the UK.

The UKHSA has activated a new technical group to create models of a possible spread of avian influenza, which includes Professor Neil Ferguson, who was instrumental in the first Covid lockdown in 2020, and the UKHSA's chief medical adviser Professor Susan Hopkins.

Documents show that the UK's Occupational Safety and Health Services Authority (UKHSA) is also looking at lateral flow tests for avian influenza and checking which laboratory-based test is best for its capture of the virus.

A source close to the matter told The Telegraph that a host of permutations had been worked out, including a U-shaped severity curve similar to seasonal flu, a scenario similar to Covid where the oldest and most vulnerable are most likely to die, and the potential for it to be dangerous to all people, like the Spanish flu.

One scenario officials investigate if the virus is relatively mild, with an infection fatality rate of 0.25 percent, similar to Covid.

The riskier hypothesis is whether the virus is as deadly in people as the 1918 Spanish flu pandemic, with a fatality rate of about 2.5 percent and a hospitalization rate of one in 20.

Some estimates of bird flu's death rate in humans are as high as 60 percent, but experts say this may be misleading and inflated by sampling bias since H5N1 first appeared 20 years ago.

This modeling represents an escalation in preparedness by health authorities as the country's worst-ever bird flu outbreak continues to devastate poultry farmers and wild bird colonies.