Epidemiologists in 36 states of the US have reported rapid spread of influenza to the federal Centers for Disease Control and Prevention (CDC), revealed data released on Friday, December 29. Cold weather gripping the United States is the major reason behind the increased influenza outbreaks. This year's flu vaccine reportedly has low efficacy.

21 among the 36 reported states have reported a high number of flu cases. According to Jennifer Radtke, manager for infection prevention at the University of Tennessee Medical Center in Knoxville, 2018 happens to be the year where only a part of the flu is covered by the vaccine. The vaccine, according to Radtke is only 10-33 percent effective. The peak period for the flu to spread rapidly in the US is around February.

The characteristics of a vaccine change year to year. Flu shot reduces the risk of influenza by 40-60 percent only when the vaccine virus matches with the flu virus, reports CDC. Radtke states that it is not uncommon to see the flu in this time of the year and that the US has faced colder Decembers before "and not had flu."

"It can take up to two weeks to build full immunity to the flu after you are vaccinated," said Cara Christ, director of the Arizona Department of Health Services.

Symptoms of influenza Fever

Body aches and chills

Extreme fatigue

Cold and cough, along with sore throat Influenza can be dangerous to those who are very young and very old, as well as pregnant women and people suffering from respiratory problems.

Since not everyone visits the hospital and gets tested, keeping a track of the actual number of people affected by influenza becomes difficult. Records of false flu test results are prevalent, thus complicating situations further. Influenza can develop into pneumonia if left untreated. The air sacs in the lungs become inflamed and are filled up with fluid.

Preventive measures against influenza Hands should be washed frequently after touching surfaces used commonly by everyone.

Toilet handles and faucets should be cleaned frequently at home.

One should cover the mouth when coughing.

Those suffering from influenza should stay at home and avoid visiting crowded places in public.

Staying hydrated helps fight the virus, as the body is properly armed.

Antiviral prescription drugs such as Tamiflu can reduce the effects of influenza and prevent pneumonia.

This year Arizona has seen a ninefold increase in the total number of flu cases, reports the State Department of Health Services. There have been reported cases of death in this season.

In Arizona, a 20-year-old mother of two died in Phoenix on November 28, just a day after she was diagnosed. Latest news is the death of a child. California saw the death of 10 people younger than 65 and the 11th death occurred on Thursday, December 28. A 47-year-old man and an 83-year-old woman died in Delaware. In North and South Carolina, 12 people, including a child and seven people aged 65 or older have died, respectively.

According to health officials, flu shots too cannot provide complete assurance to combat the virus. Pharmacists in all states can administer the flu shots. "People are able to come into the pharmacy literally any time — and be in and out usually within 15 minutes," said Jason Lind, a Walgreens pharmacist in St. Cloud, Minn.