While there is no official end to flu season, the usual peak month for flu is coming to a close, but flu activity is still widespread in most of the United States. February is the most common peak month of flu activity for the seasons from 1982 to 2016.

So far during the 2017-2018, there have been 161,129 positive tests performed by clinical laboratories and 35,544 positive tests performed by public health laboratories since Oct. 1, 2017, according to the CDC website.

There are four types of influenza viruses, which are labeled as A, B, C and D. A and B are the two viruses that cause seasonal epidemics of disease every winter.

H3N2, a strain of the influenza A virus, is the predominant strain of flu being seen during the 2017-2018 season, which could be why the 2017-2018 season seems more widespread than usual.

“We tend to see more severe seasons, especially in terms of hospitalizations and deaths among the elderly and young children, when Influenza A H3N2 is the predominant strain,” Kristen Nordlund, a National Center for Immune and Respiratory Disease press officer, said.

Contributing to a more severe season, the flu vaccine has only been 25 percent effective against Type A H3N2, and 36 percent effective overall, according to a CDC report.

In a Friday, Feb. 9, 2018 file photo, lab technologist Sharda Modi tests a patient's swab for a flu infection at Upson Regional Medical Center in Thomaston, Ga. U.S. health officials on Friday, Feb. 23, 2018, said fewer visits to the doctor last week _ 1 out of 16 _ were for fever, cough and other flu symptoms than during the previous two weeks. The number of states reporting high patient traffic for the flu also dropped, to 39 from 43. (AP Photo/David Goldman, File)

While the flu has garnered much attention this season, health officials won’t be able to tell if it was an above-average season until the end of the season.

With that being said, Nordlund said this season compares to tough seasons like the 2009-2010 season that brought the H1N1 pandemic. Numbers have surpassed those of the 2014-2015 season, which also saw high numbers due to the H3N2 strain, according to Nordlund.

“We’ve certainly seen more hospitalizations this year than we have in recent memory,” Nordlund said.

In addition to hospitalizations, the proportions of deaths attributed to pneumonia and influenza was above the system specific epidemic threshold. According to the National Center for Health Statistics, 9.5 percent of deaths during the week ending Feb. 3 were due to pneumonia and influenza. The epidemic threshold for this specific week is 7.4 percent.

A total of 97 influenza-associated pediatric deaths have been reported for the 2017-2018 season, according to the CDC Flu View. While this number is significantly lower than the 2012-2013 season when there were 170 pediatric deaths, it is close to the 2016-2017 season total of 101 pediatric deaths.

Flu shot effectiveness in question as worse-than-normal season looms for US

It’s not the common cold: How respiratory syncytial virus could threaten your child this winter

5 easily-spread illnesses that peak in fall, winter

During this particular season, it’s likely that there will be flu activity through mid-April, according to Nordlund.

“While there has been a decrease in the Influenza A positives, there has been an almost mirrored increase in the amount of Influenza B positives,” Nordlund said.

While this may seem unusual or alarming, it is common during seasons when H3N2 is the dominant strain of the flu virus, such as this year.

The CDC recommends that anyone who hasn’t been vaccinated should still do so as flu activity is still possible for weeks or even months. Visit the CDC’s Flu View for more information on flu numbers.

Report a Typo