What is H3N2 influenza virus?
Learn about H3N2, a subtype of the influenza A virus that causes seasonal flu outbreaks in humans. This article covers its transmission, symptoms, and challenges in vaccine development, as well as the increased severity of H3N2 infections in vulnerable populations.
This article provides an overview of the H3N2 influenza virus, a subtype of the influenza A virus that can cause seasonal flu outbreaks in humans. It explains how the virus is transmitted, its symptoms, and the challenges in developing effective vaccines against it. The article also highlights the increased severity of H3N2 infections in vulnerable populations and the importance of preventing their spread.
What is H3N2?
H3N2 is a subtype of the influenza A virus. The strain of the flu virus can cause seasonal flu outbreaks in humans. Like other strains of the flu, H3N2 can be transmitted from person to person through respiratory droplets produced when an infected person coughs or sneezes. The symptoms of H3N2 infections can include fever, cough, sore throat, body aches, and fatigue. H3N2 is known for its ability to mutate rapidly, making it more challenging to develop effective vaccines against it. This strain of the flu virus can be particularly severe in vulnerable populations such as young children, elderly individuals, and those with compromised immune systems. Therefore, taking precautions to prevent the spread of H3N2 during flu season is essential, including practicing good hand hygiene, avoiding close contact with sick individuals, and getting vaccinated if possible.
H3N2 History
The H3N2 influenza virus has been circulating in humans since the late 1960s. It is believed to have originated from a strain of the virus found in birds and then jumped to humans. The first reported outbreak of H3N2 occurred in Hong Kong in 1968, and it quickly spread worldwide. This outbreak caused significant illness and death, particularly in the elderly population.
Since its emergence, H3N2 has caused numerous seasonal flu outbreaks and has been responsible for some of the most severe flu seasons in recent history. For example, the 2017-2018 flu season in the United States was dominated by the H3N2 strain and resulted in an estimated 80,000 deaths, making it the deadliest flu season in over a decade.
The H3N2 virus is known for its ability to mutate rapidly, making it difficult to develop effective vaccines against it. Despite this challenge, efforts are made every year to update the flu vaccine to target the most prevalent strains of the virus, including H3N2. While numerous outbreaks and severe flu seasons mark the history of H3N2, ongoing research and prevention efforts continue to provide hope for better control and management of this influenza subtype.
H3N2 Spike
The H3N2 strain of the flu virus is causing a spike in hospitalizations in Canada and the United States. In the US, 63.3% of influenza A viruses detected and subtyped during week 8 were H3N2. Southern states report flu test positivity rates as high as 20%, mostly involving H3N2, which is known to cause more severe illness in young children and seniors.
The CDC has also identified an H3N2 variant virus circulating in swine in the mid-western United States during 2019-2020. It is unclear which other countries are affected by the H3N2 spike, as the provided search results only mention Canada and the United States. However, it is essential to note that influenza is a global disease affecting many countries yearly.
The World Health Organization (WHO) collaborates with several countries to monitor influenza activity worldwide through FluNet and Global Epidemiology Reports.
How serious is it?
The seriousness of the H3N2 influenza virus can vary depending on several factors, including the individual's age and overall health status. However, H3N2 infections can generally be more severe than other strains, particularly in vulnerable populations such as young children, elderly individuals, and those with compromised immune systems.
H3N2 is known for its high rate of mutations, which can make it more difficult to develop effective vaccines against it. This means that even if someone has been vaccinated against the flu, they may still be susceptible to H3N2 infections. In addition, the symptoms caused by H3N2 infections can be more severe, including fever, cough, sore throat, body aches, and fatigue.
During H3N2 outbreaks or flu seasons where H3N2 is prevalent, healthcare systems may become overwhelmed with many flu-related hospitalizations and deaths. For example, the 2017-2018 flu season in the United States was dominated by the H3N2 strain and resulted in an estimated 80,000 deaths, making it the deadliest flu season in over a decade.
While H3N2 can be serious, it is important to note that many people recover from the flu without complications. Taking precautions such as practicing good hand hygiene, avoiding close contact with sick individuals, and getting vaccinated if possible can help reduce the virus's spread and minimize its impact. If you experience flu symptoms, it is important to seek medical attention, particularly if you are in a high-risk group.
How is it different from flu?
The H3N2 influenza virus is a subtype of the influenza A virus. Like all flu viruses, it can cause respiratory illness with symptoms such as fever, cough, sore throat, body aches, and fatigue. However, there are some critical differences between H3N2 and the common flu.
Firstly, H3N2 is known for its high rate of mutations, which can make it more challenging to develop effective vaccines against it. This means that even if someone has been vaccinated against the flu, they may still be susceptible to H3N2 infections.
Secondly, the symptoms caused by H3N2 infections can be more severe than other strains, particularly in vulnerable populations such as young children, elderly individuals, and those with compromised immune systems. As a result, these groups may be at a higher risk of developing flu-related complications such as pneumonia or respiratory failure.
Thirdly, H3N2 can be more easily transmitted between people than other flu viruses, contributing to more widespread outbreaks and more severe flu seasons.
While there are some differences between H3N2 and the common flu, the most effective way to prevent the spread of both is by practicing good hand hygiene, avoiding close contact with sick individuals, and getting vaccinated if possible. In addition, if you experience flu symptoms, it is essential to seek medical attention, particularly if you are in a high-risk group.
Who is at risk?
Certain groups of people may be at a higher risk of developing severe illness or complications from the H3N2 influenza virus, including:
- Young children: Children under 5, particularly those under 2, are at a higher risk of developing severe illness from H3N2 infections.
- Elderly individuals: People over 65 are at a higher risk of developing severe illness or complications from H3N2 infections, including pneumonia.
- Pregnant women: Pregnant women are at a higher risk of developing severe illness from H3N2 infections and may also be at risk of complications that can harm the developing fetus.
- People with underlying health conditions: People with chronic medical conditions such as asthma, diabetes, or heart disease may be at a higher risk of developing severe illness or complications from H3N2 infections.
- People with weakened immune systems: People with weakened immune systems, such as those undergoing chemotherapy or HIV/AIDS, may be at a higher risk of developing severe illness or complications from H3N2 infections.
- Healthcare workers: Healthcare workers are at a higher risk of contracting H3N2 infections due to their close contact with sick patients.
Individuals in these high-risk groups must take extra precautions to prevent H3N2 infections, including practicing good hand hygiene, avoiding close contact with sick individuals, and getting vaccinated if possible. In addition, if you experience flu symptoms, it is important to seek medical attention, particularly if you are in a high-risk group.
Precaution
These can help prevent the spread of the H3N2 influenza virus and protect yourself and those around you from flu-related illnesses and complications. Wear a mask at crowded place. Some do's and don'ts to help prevent the spread of the H3N2 influenza virus:
Do
- Get vaccinated against the flu, including the H3N2 strain, if possible.
- Wash your hands regularly with soap and water for at least 20 seconds, or use an alcohol-based hand sanitizer.
- When coughing or sneezing, cover your mouth and nose, and dispose of used tissues properly.
- Stay home if you feel unwell, particularly with a fever.
- Seek medical attention if you experience flu-like symptoms, particularly if you are in a high-risk group.
Don't
- Don't touch your face, particularly your mouth, nose, and eyes, without washing your hands.
- Don't share personal items such as cups or utensils with others.
- Don't go to work or school if you feel unwell, particularly with a fever.
- Don't take antibiotics for the flu, as they are ineffective against viral infections like H3N2.