Updated at 2:30 p.m. Wednesday to include updates from Dallas County health officials.

Amid a flu season that’s claimed 60 lives in North Texas, health officials report that flu Type B is on the rise.

And even if you've had the flu once this season, you could get it again.

At Cook Children’s Medical Center in Fort Worth, flu B has arrived earlier this season than it has in recent years. Last week, the hospital saw 104 confirmed cases, up from 60 a week earlier.

“It's not uncommon for us to see flu B follow flu A in the flu season,” pediatrician Justin Smith said, "but because flu B has seemed to come earlier this year, we have a lot more overlap."

Those strains are trending up across North Texas and the rest of the state, too.

In December, about 14 percent of positive flu tests in Tarrant County were Type B. Now, that number has jumped to 23 percent, chief epidemiologist Russ Jones said.

Dallas County has also seen a spike in positive flu tests for both types, Dallas County Health and Human Services spokeswoman Renae Crutchfield said. This year's number of positive flu tests — 6,810 for Type A and 1,390 for Type B — are double what the county had recorded at the same time last year, she said.

Collin County has seen more cases of flu B reported as the season has progressed. Like in Tarrant County, Type B arrived earlier this season, chief epidemiologist Jawaid Asghar said.

This season’s outbreak, which is dominated by the Type A flu strain, has closed some schools in Dallas and around the state.

In Dallas County, 43 people have died from the flu — that’s more than twice the 17 who died from last season’s flu. Tarrant, Collin and Denton counties have had a total of 17 flu deaths.

How are the flu strains different?

The flu comes in four types — A, B, C and D — according to the Centers for Disease Control and Prevention.

A and B cause the seasonal epidemics we call “flu season.” Type C can cause respiratory illness but typically not epidemics like the first two. Type D is most commonly found in cattle, the CDC says, so that’s not one to worry about — unless you're a rancher.

Flu A comes in two strains: H3N2, which health officials said is this season’s most common strain across Texas, and H1N1, which is less common this season.

Flu B also is currently circulating in two strains: Yamagata and Victoria.

So how do A and B differ, symptom-wise? Not by much, officials say.

“What I typically see in the office is people with flu B have a little bit milder course,” Smith said. “Maybe the fever's not as high; they may not feel quite as bad. But of course, we'll see cases of flu B that are more severe and cases of flu A that are more mild, so it's not 100 percent.”

Flu B is typically less deadly than its Type A counterparts, Jones said.

“H3N2 is known for more mortality than the H1N1 — both are flu A,” he said. “Flu B is generally considered less severe for the general population, but it can depend on the year.”

If I've gotten the flu once this season, could I get it again?

"Unfortunately, yes," Jones said.

That's right — it's possible to get flu A, recover and then turn around and get flu B. Technically, a person could get two different strains of one type of flu, though Jones said that's unlikely.

"I've seen cases where people have gotten it in the same season," Smith said. "I've had cases where people have tested positive for both at the same time. That's definitely an outlier, but it does happen."

Which strains does the flu vaccine protect against?

If you got a flu shot this year, your vaccine included the H3N2 and H1N1 strains, as well as at least one Type B strain, Jones said.

Most flu vaccines include three or four strains — always two A strains, and either one or two B strains, depending on the vaccine.

This year’s flu vaccine is expected to be more effective against Type B, Department of State Health Services press officer Lara Anton said.

While the CDC hasn’t released data on this season’s flu shot effectiveness, she said, the vaccine is expected to be a good match against Type B since it was a good match last year.

Health officials still say your best bet to fighting this flu season is to get a flu shot and wash your hands frequently. If you’re sick with the flu, stay home from work or school until you’ve gone 24 hours with no fever without medication, Jones said.

When children have the flu, Smith said, keep a close eye on them to avoid dehydration.

“Be sure they're drinking plenty of fluids, because they just don't have as much body fluid overall, so they're a little more at risk to get dehydrated quickly,” he said.

Do your part to prevent spreading the flu

Get a flu shot.

Cover your cough with a tissue or your sleeve.

Don't go to work sick and don't drop off a sick child at a child care facility or school, where infections can spread quickly.

Wash your hands often and keep your hands away from your face.

SOURCE: Dallas County Health and Human Services