Tag: flu season

Is H1N1 Flu Back This Year?

You remember H1N1 flu, right?

Is it back this year?

Is H1N1 Flu Back This Year?

While H1N1 seems to be the most frequently identified influenza virus type this year, in reality, since causing the “swine flu” pandemic in 2009, this strain of flu virus never really went away.

It instead became a seasonal flu virus strains.

So it is back again this year, but just like it was back during the 2013-14 and 2015-16 flu seasons.

Is that good news or bad news?

In general, it’s good news, as “flu vaccines provide better protection against influenza B or influenza A (H1N1) viruses than against influenza A (H3N2) viruses.”

“The 2009 H1N1 influenza virus (referred to as “swine flu” early on) was first detected in people in the United States in April 2009. This virus was originally referred to as “swine flu” because laboratory testing showed that its gene segments were similar to influenza viruses that were most recently identified in and known to circulate among pigs. CDC believes that this virus resulted from reassortment, a process through which two or more influenza viruses can swap genetic information by infecting a single human or animal host. When reassortment does occur, the virus that emerges will have some gene segments from each of the infecting parent viruses and may have different characteristics than either of the parental viruses, just as children may exhibit unique characteristics that are like both of their parents. In this case, the reassortment appears most likely to have occurred between influenza viruses circulating in North American pig herds and among Eurasian pig herds. Reassortment of influenza viruses can result in abrupt, major changes in influenza viruses, also known as “antigenic shift.” When shift happens, most people have little or no protection against the new influenza virus that results.”

Origin of 2009 H1N1 Flu (Swine Flu): Questions and Answers

The only reason we were so concerned about this strain of H1N1 in 2009 was because it was new.

Still, even in a good year, it is important to remember that a lot of people die with the flu, including a lot of kids. And most of them are unvaccinated.

So while it might be interesting to talk about which flu virus strain is going around, just remember that your best protection against that strain is a yearly flu vaccine.

More on H1N1 Flu

Can I Get a Second Flu Shot for Extra Protection?

If one flu shot is good, wouldn’t two be better?

Can I Get a Second Flu Shot for Extra Protection?

Some people do get a second flu shot.

In fact, all kids eight years and younger, if it is their first time getting a flu vaccine, get two doses of flu vaccine.

How many doses of flu vaccine will your kids need this year?
How many doses of flu vaccine will your kids need this year?

The first dose is a priming dose and the second, at least 28 days later, is a booster dose.

Why do we do it that way?

Because studies have shown that is the best way to do it.

We don’t need to use this same priming/booster strategy in older children and adults though.

But with recent talk that protection against the flu after a flu vaccine might wane before the end of a flu season, some folks are likely wondering if they should just get another flu shot later in the season.

“Revaccination later in the season of persons who have already been fully vaccinated is not recommended.”

Prevention and Control of Seasonal Influenza with Vaccines: Recommendations of the Advisory Committee on Immunization Practices—United States, 2018–19 Influenza Season

And the official answer is no, except for younger children getting vaccinated for the first time, you should just get one dose per season.

Why not?

Mostly because a lot of studies haven’t been done to see what effect that second dose will have. And since some studies have even suggested that regular annual flu vaccines could actually lower vaccine effectiveness, you would want to know if getting an extra flu vaccine was safe and effective before we started to do it.

Not surprisingly, someone has looked into this already. One small study, Influenza revaccination of elderly travelers: antibody response to single influenza vaccination and revaccination at 12 weeks, actually showed that a second dose in the same season “did not enhance the immune response.”

So just one flu vaccine per season.

“Prior-season vaccination history was not associated with reduced vaccine effectiveness in children, supporting current recommendations for annual influenza vaccination of children.”

McLean et al on Association of Prior Vaccination With Influenza Vaccine Effectiveness in Children Receiving Live Attenuated or Inactivated Vaccine

But do get a flu vaccine every season.

Again, while there were some reports that an annual flu vaccine could lower vaccine effectiveness, other studies have disproven this.

More on Getting a Second Flu Shot

Is This Year’s Flu Vaccine Working?

Breaking News – Interim Estimates of 2018–19 Seasonal Influenza Vaccine Effectiveness have now been released (see below)

Flu season is just getting started, but I’m sure that you have already heard folks rating how well this year’s flu shots are working.

Are flu vaccines working well?
Are flu vaccines working well?

Of course, if you had a flu shot and have already gotten the flu, then you’re gonna think the flu shot isn’t working very well at all.

And if you are vaccinated and protected and have avoided the flu, then it is working so far, right?

Is This Year’s Flu Vaccine Working?

While we won’t know how well this year’s flu vaccine is working until the CDC releases the preliminary estimates on flu vaccine effectiveness, there are some good signs already.

  1. The majority of the influenza viruses collected from the United States so far have been “characterized antigenically and genetically as being similar to the cell-grown reference viruses representing the 2018–2019 Northern Hemisphere influenza vaccine viruses.”
  2. The most frequently identified influenza virus type reported by public health laboratories was influenza A(H1N1)pdm09 virus.

Remember, to be effective, you want the flu vaccine to match the strains of flu virus that are circulating in the community. A mismatch in flu virus strain or antigenic drifting leads to lower flu vaccine effectiveness (VE).

Remember the 2004-05 flu season? That was the year that because of a drifted A(H3N2) virus, “only 5% of viruses from study participants were well matched to vaccine strains.” And the flu vaccine wasn’t very effective at all.

Still, even when the flu vaccine matches circulating strains, in general, as we have certainly seen, “flu vaccines provide better protection against influenza B or influenza A (H1N1) viruses than against influenza A (H3N2) viruses.”

YearFlu Virus StrainVE
2004-05A(H3N2)10
2005-06A(H3N2)21
2006-07A(H1N1)52
2007-08A(H3N2)37
2008-09A(H1N1)41
2009-10A(H1N1)pdm0956
2010-11A(H3N2)60
2011-12A(H3N2)47
2012-13A(H3N2)49
2013-14A(H1N1)pdm0952
2014-15A(H3N2)19
2015-16A(H1N1)pdm0948
2016-17A(H3N2)40
2017-18A(H3N2)40
2018-19A(H1N1)pdm0947

So if you had to guess, you could probably say that this year’s flu vaccine is going to be at least 50% effective.

So just as good as flipping a coin? Not exactly.

There are a lot of benefits to getting a flu shot besides avoiding the flu, like avoiding severe flu, hospitalization, and death.

And since flu vaccines are safe and flu can be a life-threatening disease, even in those without any medical problems, wouldn’t you take any chance you could to reduce your child’s chances of getting sick?

When will we know how well this year’s flu vaccine is really working?

The CDC typically releases the first preliminary flu vaccine effectiveness report of the season in February.

Not that you should wait! Flu season is well underway and this is a great time to get a flu vaccine and get protected for the rest of flu season.

Interim Estimates of 2018–19 Seasonal Influenza Vaccine Effectiveness

On schedule, the CDC has released this year’s Interim Estimates of 2018–19 Seasonal Influenza Vaccine Effectiveness.

During this period, overall adjusted vaccine effectiveness against all influenza virus infection associated with medically attended ARI was 47% (95% confidence interval [CI] = 34%–57%). For children aged 6 months–17 years, overall vaccine effectiveness was 61% (44%–73%).

Interim Estimates of 2018–19 Seasonal Influenza Vaccine Effectiveness — United States, February 2019

That’s certainly better than we have seen in recent years.

More on the Effectiveness of This Year’s Flu Vaccine

Updated February 15, 2019

Vaccines and the Government Shutdown

Think that everything related to vaccines and vaccine-preventable diseases are exempted during a government shutdown?

“A shutdown furlough (also called an emergency furlough) occurs when there is a lapse in appropriations, and can occur at the beginning of a fiscal year, if no funds have been appropriated for that year, or upon expiration of a continuing resolution, if a new continuing resolution or appropriations law is not passed. In a shutdown furlough, an affected agency would have to shut down any activities funded by annual appropriations that are not excepted by law. Typically, an agency will have very little to no lead time to plan and implement a shutdown furlough.”

Pay & Leave Forlough Guideance

Nearly half of government employees have been furloughed without pay since the beginning of the most recent government shutdown, while some others are working without pay.

Vaccines and the Government Shutdown

Among those government employees who have been furloughed include nearly 40% of the staff at U.S. Department of Health and Human Services (HHS).

It would have been much more if much of HHS’s operating divisions, representing about 60% of HHS staff, had not already been funded through September 2019. So the CDC and NIH should be working as usual.

Some HHS divisions that are funded through Agriculture and Interior appropriations were hit by the shutdown though, including the EPA, FDA, and Indian Health Service.

The FDA works to regulate and approve vaccines. Will that work be affected by the shutdown?

Some of the work at the FDA is done via user fees instead of government funding, but that money is running out and they can't accept new user fees!
Some of the work at the FDA is done via user fees instead of government funding, but that money is running out and they can’t accept new user fees!

Maybe…

Most other vaccine programs likely won’t be affected though.

  • Center for Biologics Evaluation and Research (CBER) – regulates vaccine products and is financed by user fees, so doesn’t depend on government funding. Except that they can’t accept new user fees!
  • Vaccines For Children Program – already funded through the Centers for Medicare & Medicaid Services (CMS) to the Centers for Disease Control and Prevention
  • National Vaccine Injury Compensation Program – funded by an excise tax on vaccines
  • VAERS – co-administered by the Centers for Disease Control and Prevention (CDC) and the U.S. Food and Drug Administration (FDA), it is still up and running…
  • National Vaccine Program Office – funded through HHS
  • National Science Foundation – closed and no new funding opportunities will be issued and no payments will be made.
  • National Institutes of Health – funded

We are already hearing stories about what is happening as the Indian Health Service goes unfunded.

What happens if CBER runs out of money? Unfortunately, we may soon find out.

More on Vaccines and the Government Shutdown

Understanding Flu Season

Flu season starts.

A lot of folks get sick as flu season peaks.

Flu season eventually ends.

What’s to understand?

Understanding Flu Season

While we see flu activity at epidemic levels every year, some years are clearly much worse than others.

What kind of flu season will we have this year?
What kind of flu season will we have this year?

And while the severity of a flu season is easy to see after it is over, many of us could use a little help making sense of things when we are still in the middle of it.

  • Geographic Spread of Influenza Viruses – when you hear that there is widespread flu activity in a lot of states, this is what they are talking about. The only problem is that this doesn’t really tell you anything about the severity of a flu season. We get widespread flu activity in all states, or almost all states, each and every year as flu season peaks.
  • ILI Activity Indicator Map – like the maps showing the geographic spread of the flu, the ILI activity indicator map can help you tell where flu is spreading, but since it doesn’t necessarily represent the whole state, it can be misleading.
  • Influenza-like Illness Surveillance – the proportion of outpatient visits for influenza-like illness (ILI), or basically, how many people are going to the doctor with flu symptoms. Once we get above the national baseline of 2.2%, we know that flu season is starting in an area. How high can ILI get? Recently, it has peaked between 3.6% (2015-2016) and 7.5% (2017-2018). But that’s nationally. Because of wide variability in regional level data, you might see much higher ILI numbers in your state. For example, the regional baseline in Texas is 4%, while it is just 1.1% in Idaho. Still, widespread flu activity with a high ILI likely means a bad flu season.
  • Flu-Associated Hospitalizations – laboratory-confirmed influenza-associated hospitalizations. Overall, as flu season peaks, this can range from 4 to 5 per 100,000 population in a typical flu season, to 9 or 10 in a more severe flu season. This is also reported by age group. During a bad flu season, flu-associated hospitalizations will be high.
  • Mortality Surveillance – the proportion of deaths attributed to pneumonia and influenza. At some point in flu season, we get above an epidemic threshold and more people die with the flu, especially during a bad flu season.
  • Pediatric Deaths – pediatric influenza-associated deaths have been a nationally notifiable condition since the 2004 flu season and since then, on average, about 118 kids die with the flu each year. Last season was especially bad, with 185 pediatric flu deaths.

So how do you really know if it is a bad flu season?

Look for a high ILI%, high flu-associated hospitalizations, which will almost certainly be followed by a high mortality surveillance.

You also want to check viral surveillance data. Are the majority of influenza viruses being tested antigenically and genetically similar to the cell-grown reference viruses representing the 2018–2019 Northern Hemisphere influenza vaccine viruses? If not, that could mean a vaccine strain mismatch and a worse flu season.

And don’t be surprised by reports of widespread flu activity or rising ILI. That’s just flu season.

More on Understanding Flu Season

Flu Season Predictions

No, I can’t see into the future…

I predict that I will continue to get a flu shot each year, at least until they come out with a universal flu vaccine.
I predict that I will continue to get a flu shot each year, at least until they come out with a universal flu vaccine.

But some things are very easy to predict.

Flu Season Predictions

Here are some predictions for this year’s flu season.

  1. We will have a flu season epidemic in the United States this year. Surprised by that prediction? Don’t be. Flu activity reaches epidemic levels each and every year. What we don’t always have are flu pandemics, during which flu activity is very high in multiple parts of the world. By definition, flu season is an epidemic.
  2. Almost all states will eventually report having widespread influenza activity as flu season peaks. Again, this is not a bold prediction. It happens every year. How severe is flu season going to be? No one can really predict that, but we can look at the proportion of people seeing their health care provider for influenza-like illness (ILI) and laboratory-confirmed influenza-associated hospitalization rates as flu season moves along to get some idea. Remember, measures of the geographic spread of the flu don’t really tell you anything about the severity of flu activity.
  3. Dozens of kids will die with the flu – most of them unvaccinated. Remember, 37 kids died in the mildest flu season we had.
  4. A little under half of adults will get a flu vaccine, even though the current recommendation is that everyone who is at least six months old without a true contraindication get vaccinated each year.
  5. A little over half of parents will get their kids a flu vaccine.
  6. Some people who get a flu vaccine will still get the flu. You know the flu vaccine isn’t the most effective, but it still has plenty of other benefits, so even if you did still get the flu, hopefully you got a milder case, weren’t hospitalized, and didn’t die.
  7. Some people who get a flu vaccine and get the flu will blame their flu shot, even though it is well known that the flu shot can’t give you the flu.
  8. Many people who aren’t high risk will be prescribed Tamiflu. Or Xofluza, because it is new.
  9. Tens of thousands of adults will die with the flu. Even in a mild flu season, the flu is very deadly.
  10. Some folks will continue to push the idea that there is a vaginal spermicide in flu shots, even though that anti-vaccine talking point has been refuted a thousand times already.

What else can you predict about flu season?

Some folks will think it is too late to get a flu shot.

It isn’t.

Get your flu shot if you haven’t and get protected for the rest of flu season.

Another bold prediction? Elderberry syrup and Oscillococcinum are not going to help prevent or treat your flu symptoms.

More Flu Season Predictions

Are Flu Deaths Exaggerated?

A lot of people die with the flu each year.

How many? Exactly? That’s hard to know for sure.

We know how many kids die with the flu, because pediatric flu deaths are a nationally reportable condition.

At least we think we know. There were 185 reported pediatric flu deaths during the 2017-18 flu season.

“However, influenza-associated pediatric deaths are likely under-reported as not all children whose death was related to an influenza virus infection may have been tested for influenza. Therefore, we used a mathematical model to estimate the total number of pediatric deaths based on hospitalization rates and the frequency of death in and out of the hospital from death certificates, estimating that there were more than 600 deaths associated with influenza in children.”

Estimated Influenza Illnesses, Medical visits, Hospitalizations, and Deaths in the United States — 2017–2018 influenza season

The true number of pediatric flu deaths was probably far higher than the number that has been reported.

Estimating Flu Deaths

Whether or not flu deaths are a nationally reportable condition, how do we know how many people actually die with the flu each year?

“CDC does not know exactly how many people die from seasonal flu each year.”

Estimating Seasonal Influenza-Associated Deaths in the United States

Instead of counting each and every death, statistical models are used by the CDC and other public health agencies to estimate the number of seasonal flu-related deaths each year.

“For these and other reasons, statistical modeling strategies have been used to estimate seasonal flu-related deaths for many decades. Only counting deaths where influenza was included on a death certificate would be a gross underestimation of seasonal influenza’s true impact.”

Frequently Asked Questions about Estimated Flu Burden

And these statistical models that have been improved and updated over the years. That’s why instead of the general “36,000 flu deaths a year” that we used to see, we get more specific estimates of flu deaths each and every year.

CDC estimates that influenza has resulted in between 9.3 million – 49.0 million illnesses, between 140,000 – 960,000 hospitalizations and between 12,000 – 79,000 deaths annually since 2010.”

Disease Burden of Influenza

Why such a big range in the estimates?

Some flu seasons are worse than others.

The 2017-18 flu season, for example, was especially bad, “with an estimated 48.8 million people getting sick with influenza, 22.7 million people going to a health care provider, 959,000 hospitalizations, and 79,400 deaths from influenza.”

Were there definitely 79,400 deaths?

No, again, that’s an estimate. There were likely somewhere between 69,000 (low range of the estimate) and 99,000 (high range of the estimate) flu deaths.

It’s hardly a guess though, as anti-vaccine folks seem to imply.

The estimates come from analyzing data from the Influenza Hospitalization Surveillance Network (FluSurv-NET), which is made up of 267 acute care hospitals and laboratories in 13 states and has comprises over 27 million people.

Are Flu Deaths Exaggerated?

Not surprisingly, anti-vaccine folks don’t like to hear about deaths from vaccine-preventable diseases. They would much rather exaggerate the risks of vaccine injuries!

Minimizing the risks of vaccine-preventable disease comes straight from the anti-vaccine propaganda playbook.
Minimizing the risks of vaccine-preventable disease comes straight from the anti-vaccine propaganda playbook.

And guess what? None of the folks challenging the CDC’s “influenza math” seem to be epidemiologists or statisticians. They are just folks who want to scare you away from getting a flu shot.

“It takes little subtlety to recognize that the principal reason for flu hyperbole is to sell more vaccines. However, more and more people—even infectious disease specialists—are realizing that flu shots are fraught with problems. Roughly four-fifths of the vaccine injury and death cases settled through the National Vaccine Injury Compensation Program are flu-vaccine-related.”

Robert F. Kennedy, Jr on The CDC’s Influenza Math Doesn’t Add Up: Exaggerating the Death Toll to Sell Flu Shots

Speaking of flu hyperbole, Kennedy doesn’t mention that there have only been about 2,500 flu-vaccine related compensated cases through the National Vaccine Injury Compensation Program since 2006, even though at least 1,372,400,000 doses (yes, that billions!) of flu vaccine have been distributed since that time!

And although Kennedy calls those all “vaccine injury and death cases,” folks should be aware that since 1988, the number of “death cases” is far fewer than 2,500. In fact, there have been 157 filed death cases in the NVICP for the flu vaccine among billions of doses of flu vaccine given. Even then, we don’t actually know how many of those 157 cases were compensated, settled, or dismissed. It’s still a relatively small number though.

Vaccines are safe. The flu, like other vaccine-preventable diseases, is deadly. If you don’t believe the estimates, go visit an ICU during flu season and verify just how deadly the flu can be.

Get a flu vaccine each year and get protected against the flu.

More on Flu Deaths