What You Need to Know About the Deadly New Flu Strain H3N2

What is the New Flu Strain?

The new flu strain causing concern this season is known as influenza A (H3N2). H3N2 is a subtype of influenza A virus that tends to cause more severe flu seasons. It has been around since the late 1960s but the strain circulating this year has mutated and is different from past seasons.

Key facts about H3N2:

• Causes more hospitalizations and deaths than other flu strains
• Disproportionately affects the elderly
• Has a higher resistance to the flu vaccine
• Spreads quickly and causes more activity earlier in the season

Where Did the New Flu Strain Come From?

Flu viruses constantly change and mutate year to year. The H3N2 strain that emerged this flu season originated in Asia. As the virus spread and made its way around the world, it continued to mutate into new variations. The predominant H3N2 strain this year evolved from strains that were circulating in the past two seasons.

Factors leading to new flu strains:

• Random genetic mutations as the virus replicates
• Reassortment - swapping genes between strains
• Cross-infection between humans and animals
• Increased transmissibility between birds, pigs and people

Is the New Flu Strain Deadlier?

Early indications suggest the new H3N2 strain is linked to more hospitalizations and deaths, especially among older adults and very young children. The virus tends to hit seniors harder as their immune systems weaken with age. Children under 5 also have high hospitalization rates.

Reasons H3N2 can be more severe:

• Efficient at entering lung cells and replicating
• Causes more inflammation in the lungs
• Can lead to more bacterial pneumonia infections
• Pre-existing health conditions raise risks

At-Risk Groups for Severe Illness

• Adults 65+ years old
• Children younger than 5
• Pregnant women
• Those with chronic conditions like asthma, diabetes, heart disease

How Well Does the Flu Shot Work Against H3N2?

Flu vaccination generally provides less protection against H3N2 compared to other strains like H1N1. Vaccine effectiveness was estimated around 30% for H3N2 last season. The virus mutates faster than other flu strains so there is often a mismatch with the vaccine.

Factors reducing vaccine effectiveness:

• Rapid mutation of circulating strains
• Age-related decline in immune response
• Low initial immune response to the vaccine
• Waning immunity over the flu season

Benefits of Getting the Flu Shot

• Reduces risk of infection
• Decreases severity if infected
• Lowers hospitalization rates
• Provides immunity against other flu strains

What Flu Symptoms Does H3N2 Cause?

The signs and symptoms of H3N2 flu infection are similar to seasonal flu strains and can include:

• Fever and chills
• Cough
• Sore throat
• Runny or stuffy nose
• Muscle aches and headache
• Fatigue
• Nausea, vomiting and diarrhea (more common in children)

Flu symptoms tend to be more severe with H3N2 compared to other strains, leading to higher rates of complications.

Emergency Warning Signs

• Difficulty breathing or shortness of breath
• Pain or pressure in the chest
• Confusion or sudden dizziness
• Severe vomiting
• Flu-like symptoms that improve but then return with fever and worse cough

How Does H3N2 Spread So Quickly?

The H3N2 strain has certain characteristics that enable it to spread rapidly and efficiently. It has a higher reproduction number indicating how many additional people will be infected by one contagious person. H3N2 seems to multiply faster and reach higher viral concentrations in the body.

Reasons H3N2 can spread quickly:

• Efficiently enters and replicates in human nasal and lung cells
• Causes more sneezing, coughing and mucus production
• Some individuals spread infection before showing symptoms
• Can survive longer than other strains on hard surfaces

Ways H3N2 Spreads

• Coughing and sneezing droplets
• Direct physical contact
• Touching contaminated surfaces then face
• Through the air in closed environments

Are There Treatments for H3N2 Infections?

Antiviral medications like Tamiflu (oseltamivir) and Relenza (zanamivir) can lessen the severity and duration of H3N2 if taken early on. Most people recover on their own with rest, fluids and over-the-counter symptom relief. Some individuals, especially at-risk groups, may require hospitalization.

Medical treatment options may include:

• Antiviral medication for 5 days
• IV fluids for dehydration
• Oxygen therapy for breathing issues
• Medications to lower fever
• Antibiotics for secondary infections

Self-Care Measures

• Rest and sleep
• Drink plenty of fluids
• Use a humidifier
• OTC medications for symptoms
• Chicken soup and warm liquids

How Can I Avoid Getting H3N2?

The best way to prevent H3N2 infection is to get the annual flu shot. It provides protection against multiple flu viruses even if effectiveness against H3N2 is modest some years. Avoiding exposure through good hygiene practices is also key.

Tips to avoid getting sick:

• Get the flu shot every year
• Wash hands frequently
• Use alcohol hand sanitizer when out
• Avoid touching your face
• Stay away from sick people
• Disinfect frequently touched surfaces

Protective Measures

• Flu shot/nasal spray vaccine
• Face masks
• Hand washing
• Surface disinfection
• Social distancing

Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult with a healthcare professional before starting any new treatment regimen.