Official statement: Facing a disease with a 50% mortality rate, the United Nations and the World Health Organization both recommend that these people get vaccinated

After 8 years, Cambodia once again reported cases of H5N1 highly pathogenic avian influenza (HPAI), resulting in one death and one asymptomatic infection .

Is H5N1 a big disease burden? Why is H5N1 so concerning? How can we reduce the risk of H5N1? Is there an H5N1 vaccine? You will find out after reading this article.

[Reappearance of human H5N1 cases]

They have 22 chickens and 3 ducks.

On February 16, an 11-year-old girl in a village in Prey Veng Province in southern Cambodia developed flu-like symptoms and was treated locally. She then developed a more serious condition ( severe pneumonia ) and was sent to a hospital in Phnom Penh, the capital of Cambodia, for treatment.

At first, the girl's symptoms did not seem serious - body temperature 102℉ (38.9℃), cough, sore throat , but no other obvious symptoms.

Sequencing of the samples determined that the girl was infected with the H5N1 avian influenza virus, belonging to the 2.3.2.1c evolutionary branch , which is similar to the 2.3.2.1c evolutionary branch virus that has been prevalent in poultry in Southeast Asia since 2014.

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The girl died last Wednesday after being diagnosed with the influenza A (H5N1). Her father was also found to be infected with H5N1, but fortunately, the 49-year-old man was only asymptomatic . However, according to Reuters, at least 12 people in Cambodia have been tested.

As for the source of the virus, after investigation, the local authorities determined that it came from a small number of poultry raised at home. These poultry, including some birds in the surrounding area, have died .

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In addition to some local actions, the Ho Chi Minh City People's Committee on Sunday called for close monitoring of arrivals from areas affected by the H5N1 avian influenza outbreak as Vietnam borders Cambodia's Prey Veng province.

It seems that both Cambodia and Vietnam have become very nervous because of these two cases of infection.

[Less morbidity, higher mortality]

Why is H5N1 receiving so much attention?

It has been nearly 10 years since the last case in Cambodia (2014) . In the past 10 years, Cambodia has not had any human cases of avian influenza. Going back further, Cambodia has only reported 128 human cases of H5N1 infection since 2003.

In the past 20 years, there have been less than 130 infections, with an average of only 6.5 infections per year . Is it necessary to make such a fuss about H5N1?

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Let's look at H5N1 from a different perspective.

From 2003 to February 25, 2023, a total of 873 H5N1 human cases and 458 deaths were reported in 21 countries worldwide, with a case fatality rate of 52.5% (458/873); in Cambodia alone, 128 cases of H5N1 infection were reported during this time frame, of which 64 people died, with a case fatality rate of 50% (64/128).

Although unlike rabies, where the mortality rate is close to 100% once the disease occurs, the threat of H5N1 is already terrifying enough for people who are almost one foot into the underworld after being infected.

Will H5N1 become a pandemic?

Perhaps this is a comforting answer: not yet.

Although the mortality rate of H5N1 is as high as 50%, and in this Cambodian case not only the girl was confirmed to be infected but also her father, this does not mean that H5N1 has been transmitted between people .

Interspecies transmission of influenza A, source: doi: 10.1128/CMR.00037-06

Between 1959 and 1990, there were 17 outbreaks of highly pathogenic avian influenza worldwide, five involving turkeys and 12 involving chickens, all of which were effectively controlled by culling poultry.

Subsequently, the first outbreak of highly pathogenic avian influenza (H5N1) occurred in Hong Kong in 1997, with 6 deaths among 18 confirmed cases. The virus was eventually identified as the " goose flu " virus isolated from Guangdong geese in 1996 (A/goose/Guangdong/1/1996 (Gs/GD/96)).

Avian influenza outbreak, source: doi: 10.1179/2047773213Y.0000000103

Since then, the "goose flu" virus lineage has been detected in more than 70 countries and regions, but the number of cases is relatively small, and there is currently insufficient evidence for person-to-person transmission of H5N1 .

Of course, there is currently a lack of evidence of human-to-human transmission, just as there was a lack of evidence for the new coronavirus at the beginning. What will happen in the future still requires closer attention .

【Attitude of international organizations】

After the H5N1 cases were reported in Cambodia, the World Health Organization (WHO) issued an information notification on February 26, 2023, noting that "an outbreak investigation is ongoing, including determining the virus exposure circumstances of the two reported cases."

The World Health Organization also emphasized several recommendations for the prevention and control of avian influenza, which are briefly described as follows:

Continue to monitor the epidemiology, clinical features, and impact of avian influenza virus on humans and share information promptly;

Sampling and culling of poultry in areas where cases have occurred, and relevant personnel should take protective measures and be closely monitored;

A thorough epidemiological investigation should be conducted for suspected or confirmed cases, and relevant samples should be tested and sent to WHO Collaborating Centers for further identification.

Source: https://www.who.int/emergencies/disease-outbreak-news/item/2023-DON445

In addition, the World Health Organization also mentioned information about the H5N1 vaccine, which mainly includes two points :

1. There is a pandemic H5N1 avian influenza vaccine, but it has not yet been widely used in the human population;

2. People who come into contact with or work with poultry should be vaccinated with seasonal influenza vaccine to reduce the risk.

In fact, many countries and regions, including China, have the ability to develop and produce H5N1 vaccines. China has also previously developed inactivated H5N1 vaccines for strategic reserves , but has not (and there is no need to) universally vaccinate them.

After the WHO released the above information, the United Nations (UN) also synchronized the information about the avian influenza cases in Cambodia and forwarded the recommendation that " relevant populations are recommended to receive seasonal influenza vaccination ."

Image source: https://news.un.org/en/story/2023/02/1133922

For the general public who do not have "close contact" with poultry, they do not need to pay too much attention to the threat of avian influenza - at least not in the short term.

In the face of the recent aggressive influenza A (mainly H1N1 and H3N2 , in fact H5N1 is also a type of influenza A), perhaps many people have realized that not only people who come into contact with poultry should be vaccinated against influenza, but also people who are susceptible to this disease need to be vaccinated.

As the saying goes: When it comes to a flu epidemic, being late is not necessarily better than not getting it at all; when it comes to a flu vaccination, getting it late is better than not getting it at all.

May the world be free of epidemics

=Pill=

Disclaimer: This article was created out of personal interest, only to help more ordinary people have a clearer understanding of vaccines. The content and views do not represent any organization, unit, or institution, and it has not accepted any form of sponsorship. All pictures, except those specially marked, are from the depositphotos platform for which personal use rights have been paid for. If the content is incorrect, please criticize yourself more (not).