H3N2 virus: Can your COVID shots protect you from getting a severe infection?

Just as we were heaving a sigh of relief for the past few months with lesser numbers of COVID cases, the emergence of infections due to H3N2 virus has triggered a fresh wave of concern in the country.

An infection caused by the H3N2 virus or the influenza A virus is characterized by high fever, breathing issues, fatigue, and dry cough. The symptoms linger in the body for as long as 3 weeks, experts say.

However, for those who have closely watched the novel coronavirus spread and mutate for over 3 years it is impossible to remain calm with the flu virus spreading nationwide. People have several questions on the symptoms, severity and whether the COVID vaccines which have been taken in 2-3 doses are effective in protecting against flu.

"No it won’t, as the two viruses are very different," says Dr. Kuldeep Kumar Grover, Head of critical care & Pulmonology - CK Birla Hospital, Gurgaon.

“Since the virus causing COVID infection is completely different from that inflicted with H3N2, the vaccines will be different and the COVID vaccine will not help in protecting against influenza. There are other vaccines, flu shots and influenza vaccines available which helps in preparing the immune system for the fight against the particular disease/ virus,” the expert explains.

“Vaccine against any virus is made depending on the nature of the virus, its morphology, proliferation rate etc, thus it is important to understand that the particular vaccines will only trigger the immune system to respond correspondingly to the virus,” he adds.

"The H3N2 is antigenic drift & a mild mutation, but is not life-threatening. Whichever virus it is, if there’s comorbidity then the chances of death is high. The vaccine against H3N2 has less efficacy & our vaccination is low this year," Dr Dhiren Gupta, Ganga Ram Hospital told news agency ANI.

India experiences two peaks of seasonal influenza viral infection, one from January to March and the other after monsoon season.

In India there are three subtypes of influenza viruses: Influenza A H1N1pdm09, Influenza A H3N2 and Influenza B Victoria, of which Influenza H3N2 is the predominant subtype among the samples testing positive for influenza, since the beginning of this year, the union health ministry has confirmed.

“Children and senior citizens are the ones at most risk of the H3N2 virus as it attacks the immune system of a person,” says Dr Grover.

“In particular, children or elders with asthma, heart disease, diabetes, obesity, and weakened immune systems are at an increased risk of contracting the H3N2 virus. Even pregnant women are at risk of contracting the virus,” he explains.

Doctors have also said that the number of flu cases in kids is rising because for the last 2 years the kids have not been exposed to other viruses as schools and educational institutes were shut down as a part of government's lockdown measures to contain the spread of COVID causing coronavirus. "Since 2 years because of Covid there was no exposure of influenza to children, because of this the sudden outbreak of H3N2 virus which a normal variant of influenza variant has caused increase in number of cases in children," Dr Gupta added.

"Being a contagious disease, the H3N2 Influenza Virus can spread from one person to another via droplets from an infected person's cough or sneeze and through droplets coming in contact with the hands of an uninfected person," explains Dr Grover.

“To avoid contracting the infection, it is essential to practice good hygiene. Avoid crowded areas, and when out in public, don a mask. In particular, wash your hands with soap and water before eating and after utilizing public transportation. In cases where you are unable to cleanse your hands, use hand sanitizer. It is also advised for people to stay away from individuals who are sick,” he suggests.

Mild or not, it is important to confirm the infection and get medical help at the earliest. The common signs of H3N2 virus infection are fever or feverish chills, cough, sore throat, runny nose or in some cases congested nose, headaches, and fatigue.

Kids, and sometimes adults too, might experience vomiting and diarrhea.

Difficulty in breathing is also another classic sign of H3N2 virus infection. Kids are likely to show wheezing symptoms.

Two years of dealing with COVID has taught us that wearing masks and sanitizing hands before touching mouth and eyes can cut down the chance of the virus from entering the body.

Now since the time has come to deal with a seasonal influenza virus let's recollect the antiviral protocol that we followed for COVID.

Avoid close contact with those who have flu or those who show the symptoms of flu. Stay at home if you feel sick or if you have symptoms unless and until it is very necessary. Cover your mouth and nose with a mask when you are in a crowded place. Clean your hands frequently and avoid touching your eyes, mouth and nose with unclean hands.

​H3N2 flu: Warning signs you may be infected; tips to prevent catching the virus​