Flu season has been tough in Michigan. Schools are closing and influenza rates are spiking.

Learn why this year's flu has been so widespread and severe in Michigan.

Over 80 percent of positive influenza tests in Michigan are showing a Hong Kong flu-like virus. The exact strain being found in Michigan and across the country is similar to Influenza A (H3N2) Hong Kong 2014. 501 people died from the flu in Hong Kong in 2014. Hong Kong also experienced a flu vaccine shortage that year.

It's important to note that since Oct. 1, the Michigan Department of Health and Human Services reports no flu-related deaths in Michigan. However, there have been 17 pediatric and 118 adult flu-related hospitalizations reported in Michigan.

Unfortunately, I can speak from experience about the strength of the viruses going around right now. So can my wife and three kids. We've all been sick over the last two weeks and can confirm that whatever is going around is a very strong illness.

As Michigan flu levels continue to spike and schools close due to influenza, we are seeing similar results across the country. The CDC reports that there have been 38,244 clinical laboratory-confirmed cases of influenza nationwide since Oct. 2, 2016 with 87.7 percent testing positive for influenza A viruses. Public health laboratories found 15,781 confirmed cases of influenza. 92.6 percent were influenza A with 97.5 percent of those samples being influenza A (H3N2).

I talked to Angela Minicuci with the Michigan Department of Health and Human Services Communications Office about why the flu is so strong this year. She explained, "In previous years where A (H3N2) strains predominate, they have been associated with more severe illness and higher mortality, especially in older people and young children, relative to H1N1 or B predominant seasons."

Influenza A strains are the most severe. They are also the most resistant to vaccines. The CDC reports that this season's vaccine has been effective 43 percent of the time against influenza A (H3N2). The vaccine has been effective 73 percent of the time against influenza B.

The good news is that this season's vaccine includes protection against the proper version of influenza A (H3N2). The bad news is the virus is so strong it's an uphill battle for many.