With weather changes, the flu cases have begun to rise and it is the flu season that is going on. The flu is termed a respiratory illness caused by the influenza viruses which are of four types A, B, C, and D but only A, B, and C can spread to humans. Seasonal epidemics of respiratory illness are caused by Influenza A and B which occur every year.
Further Influenza A viruses are divided into different subtypes hemagglutinin (HA) and neuraminidase (NA). The Influenza A viruses that we are familiar with are H1N1( also known as swine flu) and H3N2.
Let’s know more about H3N2
Flu seasons that are dominated by H3N2 activity are more severe, particularly among older adults and younger children. The flu symptoms of H3N2 are similar to the other seasonal influenza viruses that include:
1. Cough
2. Runny or congested nose
3. Sore Throat
4. Headache
5. Body aches and pains
6. Fever
7. Chills
8. Fatigue
9. Diarrhoea
10. Vomiting
H3N2 Diagnosis
Cold is a common symptom in H3N2 and is similar to other respiratory illnesses. Therefore just by observing the physical symptoms, it is quite difficult to say whether a person has the stated flu.
Only a healthcare professional can confirm for flu or some other illness by conducting lab tests. However, most of the patients are diagnosed with flu without conducting lab tests if they are suffering from flu-like symptoms during the traditional flu season.
H3N2 Vaccine
Three or Four Strains of flu can be prevented each year by the annual flu vaccine known as trivalent and quadrivalent vaccines respectively. Trivalent vaccines include H1N1, H3N2, and influenza B strains whereas an extra influenza B stain is included in quadrivalent vaccines.
As per CDC when the vaccine strains are a good match to circulating strains it reduces the risks of flu illness between 40 and 60 percent in the general population.
The flu vaccine is capable of offering more protection from the flu caused by the H1N1 viruses and Influenza B viruses as compared to H3N2 viruses. This can be explained as follows:
While other viruses mutate from year to year, H3N2 mostly undergoes genetic changes that result in a poor match between the strain included in the vaccine and the strains that later circulate during flu season.
Many flu vaccines are produced in eggs and H3N2 viruses tend to adapt to growth in eggs more readily than other types of flu viruses which leads to less effectiveness of the vaccine strain.
Egg-adaptation problems will persist till the flu vaccines are produced in eggs. While the H3N2 still contains the same egg-adapted mutation even the vaccine strain that was recommended for the 2018/19 flu season is different from the previous season’s H3N2 strain.
H3N2 Treatment
The treatment is about managing the symptoms while recovering by following certain ways:
1. Getting enough rest
2. Keeping yourself hydrated
3. Taking the medications to get relief from symptoms such as fever, headaches, and other aches and pains.
4. In some cases, patients might be recommended antiviral medication, such as oseltamivir (Tamiflu). If taken within 48 hours after developing the flu symptoms, these medications help in shortening the duration of illness and also prevent complications if any develop.
Some people can develop serious complications from the flu like pneumonia or the worsening of a pre-existing medical condition, such as asthma.
One needs to visit the doctor if one suspects the flu and belongs to the following age groups
1. Adults of age 65 and above.
2. Children under 5
3. Pregnant women
4. People with chronic medical conditions like asthma, diabetes, or heart issues.
5. Patients with the weak immune systems due to medication (steroids, chemotherapy) or a medical condition (HIV, leukaemia)
H3N2 Outlook
People suffering from seasonal flu at home without consulting the doctor. While symptoms ease within a week, cough and fatigue can stay a couple of weeks more.
People lying in higher-risk groups can consult a doctor once diagnosed with flu symptoms.
Symptoms that need medical emergency include:
Trouble in breathing
Pain or pressure in the chest or abdomen
Sudden dizziness
Persistent or severe vomiting
Improved symptoms returns with worsened cough and fever
H3N2 Prevention
We can prevent falling ill with seasonal flu viruses by taking the following steps:
Annual vaccination can be taken every year
Frequent hand washing particularly after using the restroom, before eating, and before touching your face, nose, or mouth.
Avoid crowded places.
Avoid coming in contact with sick people.
A patient suffering from flu can prevent the spread and transmit it to others by staying home until 24 hours after the fever has gone down and ensuring covering their mouth when they cough or sneeze.