Tag: flu season

Is the Flu Deadlier This Year?

Why do people seem to think that the flu is deadlier this year?

Everyone has a prediction about flu season, but it is still too early to tell if this year will be deadlier than others.
Everyone has a prediction about flu season, but it is still too early to tell if this year will be deadlier than others.

It seems like we get these kinds of warnings and predictions every year.

Is the Flu Deadlier This Year?

Is it true this year?

“Levels of outpatient ILI remain elevated; however hospitalization rates and percent of deaths due to pneumonia and influenza remain low. This is likely due to the predominance of influenza B/Victoria and influenza A(H1N1)pdm09 viruses which are more likely to affect children and younger adults than the elderly. Because the majority of hospitalizations and deaths occur among people age 65 and older, with fewer illnesses among that group, we expect, on a population level, to see less impact in flu-related hospitalizations and deaths.”

Weekly U.S. Influenza Surveillance Report, Key Updates for Week 1, ending January 4, 2020

It is certainly true that we are seeing more pediatric flu deaths at this time of year than usual, but we don’t usually have such an early start to the flu season!

“This season so far has been particularly deadly for children, with 27 deaths reported through December 28. That’s the highest number of deaths at this point in the season since the CDC started keeping track 17 years ago.”

Elizabeth Cohen on US on track for one of the worst flu seasons in decades

If flu season also peaks and ends earlier than usual, than it might not end up being an overly severe flu season.

Will it be a deadly flu season?

Of course.

It’s flu season!

“The overall cumulative hospitalization rate was 14.6 per 100,000 population which is similar to what has been seen during recent previous influenza seasons at this time of year.”

Weekly U.S. Influenza Surveillance Report, Key Updates for Week 1, ending January 4, 2020

But there is not yet good evidence that this season is or will be much worse or deadly than others.

Influenza-like Illness numbers don't say anything about the severity of flu illness.
Influenza-like Illness numbers don’t say anything about the severity of flu illness.

Or that this year’s flu vaccine won’t be effective. We won’t get a report on the effectiveness of this year’s flu vaccine until next month.

“Although the V1A.1 and V1A.3 subclades are genetically distinct, sera from previous studies conducted among humans vaccinated with a V1A.1 virus cross-reacted well with B/Victoria viruses with a three amino acid deletion, such as the V1A.3 viruses. These findings suggest that vaccination with the current season’s vaccine might offer protection against circulating B/Victoria viruses.”

Early Season Pediatric Influenza B/Victoria Virus Infections Associated with a Recently Emerged Virus Subclade — Louisiana, 2019

And while we already know that this year’s flu vaccine isn’t a perfect match, it should offer protection.

Flu mortality surveillance data is still below epidemic threshold, although it is unlikely to stay there much longer.
Flu mortality surveillance data is still below epidemic threshold, although it is unlikely to stay there much longer.

Unfortunately, early flu seasons don’t always peak and end early. And they are sometimes among the worst, like the 2012-13 flu season. But that was an H3N2 season, which often are worse than others.

This year we are in new territory, having an early season that has been dominated by a flu strain B. Since it is not something we have seen before (at least not since the since the 1992–93 season), you can expect the unexpected, just like you should always do when it comes to the flu.

And know that there is really only one prediction that will end up holding true, that a yearly flu vaccine is the best way to protect your family from the flu.

More on Flu Deaths

Do Flu Vaccines Cause RSV?

Why do some people think that getting a flu vaccine can cause them to get RSV?

Flu vaccines do not cause RSV.
Flu vaccines do not cause RSV.

The usual suspects…

Do Flu Vaccines Cause RSV?

Like the flu, RSV or respiratory syncytial virus, causes infections during cold and flu season.

Unlike the flu, we don’t yet have an RSV vaccine, but that hasn’t stopped anti-vax folks from trying to link them together.

Of course it is silly think that a flu shot could cause a child to develop RSV.

For one thing, you can just look at who gets RSV, especially severe RSV infections.

“The average seasonal RSV hospitalization rate in this study was 5.2 per 1000 children who were <24 months old, but the rate varied by season as much as fourfold. Nevertheless, 1-month-old infants consistently were most likely to be hospitalized, almost twice as often as the next 2 most at-risk groups: infants <1 month old and infants 2 months old. These youngest infants accounted for an important proportion of all children admitted with RSV infection in the first 2 years of life: 11% were infants <1 month old, 44% were ≤2 months old, and only 36% were >5 months old.”

Hall et al on Respiratory syncytial virus-associated hospitalizations among children less than 24 months of age

While anyone can get RSV, even adults, it is infants who are under 6 months old that typically are at the greatest risk to have severe infections. And of course, these kids are too young to even have a flu vaccine!

The other reason?

It is no surprise that the flu vaccine delays of 2015 didn’t affect RSV season…

RSV season not only starts before flu season, but often before the time when we are even giving flu vaccines!

Anyway, the whole idea that “RSV is an adverse reaction from flu vaccine” comes from the misuse of a study, Increased risk of noninfluenza respiratory virus infections associated with receipt of inactivated influenza vaccine, that doesn’t even mention RSV.

“Being protected against influenza, TIV recipients may lack temporary non-specific immunity that protected against other respiratory viruses.”

Cowling et al on Increased risk of noninfluenza respiratory virus infections associated with receipt of inactivated influenza vaccine

And it is very important to keep in mind that it was a small study about interference caused by non-specific immunity.

Another larger study that did include RSV, “Influenza vaccination is not associated with detection of noninfluenza respiratory viruses in seasonal studies of influenza vaccine effectiveness,” found that “influenza vaccination was not associated with detection of noninfluenza respiratory viruses.”

What to Know About Flu Vaccines Causing RSV

The bottom line is that flu vaccines do not cause RSV and do not increase your risk of getting RSV.

More on Flu Vaccine Side Effects

The 2019-20 Flu Season Update

Breaking News: The 2019-2020 season is well underway, but flu activity has “declined slightly.” (see below)

It is way too early to tell if flu season has peaked...
It is way too early to tell if flu season has peaked…

Flu season started early this year.

The 2019-20 Flu Season Update

That’s not the only surprise though. We are seeing a lot of flu B, which is also unusual for the beginning of flu season.

And we are already seeing quite a few pediatric deaths – 39 so far this season.

The overall cumulative hospitalization rate was 19.9 per 100,000 population which is similar to what has been seen during recent previous influenza seasons at this time of year.
The overall cumulative hospitalization rate was 19.9 per 100,000 population which is similar to what has been seen during recent previous influenza seasons at this time of year.

But none of this should really be a surprise – it’s flu season, which is always unpredictable.

“It’s not too late to get vaccinated. Flu vaccination is always the best way to prevent flu and its potentially serious complications.”

Weekly U.S. Influenza Surveillance Report

Some things to know to about this year’s flu season include that:

  • the most active flu B virus strains belong to a sublade that was not in the flu vaccine, but is similar enough that getting vaccinated should offer protection
  • again, it is never too late to get a flu vaccine. Remember, a yearly flu vaccine is recommended for everyone without a contraindication who is at least six months old, with younger children getting two doses during their first season.
  • anti-viral flu medications (Tamiflu, Relenza, and Xofluza) are available, but are mainly recommended for those who are at high risk for serious flu complications, including young children (under 2 to 5 years of age), pregnant women, seniors, and those with chronic medical conditions, like asthma and diabetes, etc.
  • most people do not need a flu test, as it is possible to have a negative flu test and still have the flu (false positive test) and most people don’t need to be treated with anti-viral flu medications
  • if you get the flu, avoid others and seek medical attention if you develop any serious, emergency warning signs, like trouble breathing, dehydration, or confusion, etc.
  • people with the flu can generally return to school or work once they are fever free for at least 24 hours

And let’s hope we don’t see any other surprises this year…

More on the The 2019-20 Flu Season Update

Will This Season’s Flu Shot Fail?

Flu season hasn’t even started yet, but we are all seeing anti-vax myths warning that the flu shot will fail in epidemic numbers. Where are they coming from?

Most of these anti-vax folks don't think that any vaccines work...
Most of these anti-vax folks don’t think that any vaccines work…

A lot of it is from the usual suspects…

Will This Season’s Flu Shot Fail?

Anyway, is there anything to this?

Can anyone really predict whether or not this season’s flu vaccine will be effective or if it will fail?

Probably not.

What they can do is scare folks into thinking that the flu vaccine won’t work, so that they don’t get vaccinated and protected, ensuring that we really will have a bad flu season!

Consider last fall. Many were predicting a mild flu season in North America following a mild season in the Southern Hemisphere and yet, 136 children died.

And this year?

Will a moderate to severe flu season in the Southern Hemisphere mean that we will be seeing a severe flu season too?

Maybe, but consider that the issue in the Southern Hemisphere wasn’t a vaccine mismatch.

Last year's flu vaccine in Australia was a good match.

They had a good match with their flu vaccine. The problem was just that they had a lot of flu!

So why do folks think that we will have a mismatch?

The A strains in the southern and northern hemisphere flu vaccines are different.

It’s because the A strains in the Southern and Northern Hemisphere flu vaccines are different, which is a little unusual, but not unheard of.

“Additional data obtained in recent weeks has confirmed the wide regional differences in the relative proportion of A(H3N2) viruses belonging to the phylogenetic subclade 3C.2a1b and clade 3C.3a. The majority of A(H3N2) viruses collected and genetically characterised from September 2018 to February 2019 belonged to the phylogenetic subclade 3C.2a1b; however, the proportion of viruses falling into clade 3C.3a has increased substantially since November 2018 in several countries in western Europe, Israel and especially in the United States of America.”

A lot of work goes into figuring out which strains to include in each year’s flu vaccine and that got us to where we are now.

Unfortunately, a lot of different flu vaccine strains circulate each season, which is why some folks get sick even though they have been vaccinated.
Unfortunately, a lot of different flu vaccine strains circulate each season, which is why some folks get sick even though they have been vaccinated.

Did they make the right decision?

Is our flu vaccine a match?

Some folks are saying that since they changed it again, for next year’s southern hemisphere flu vaccine, then they must have messed up.

So which flu virus strains are circulating so far? Will it be the 3c3.A clade of H3N2 that is in our flu vaccine? Will it be an H1N1 virus?

Of course, it is too early to tell.

“A/H3N2 viruses continue to show substantial diversity in HA sequences with a deep split between 3c3.A and 3c2.A1b viruses. The most notable recent developments are the rapid rise of clade A1b/137F – a subclade of A1b/135K – in China and Bangladesh and clade A1b/197R – a subclade of A1b/131K – which dominates the ongoing season in Australia. Our models predict that A1b/137F and A1b/197R will be the dominant clades next year with A1b/197R accounting for most circulation. There is, however, large uncertainty in the true extent of A1b/137F circulation.”

Bedford et al on Seasonal influenza circulation patterns and projections for September 2019 to September 2020

While we are seeing sporadic cases, flu activity is very low, which makes it a great time to get vaccinated and protected, before flu season really gets started.

And the predictions of a failed flu vaccine?

“Over the last 18 months, 3c3.A viruses have increased markedly in the US and Europe and accounted for 60% of isolates in North America and 10-20% in Europe during the last NH winter.”

Bedford et al on Seasonal influenza circulation patterns and projections for September 2019 to September 2020

I won’t let it get in my way of getting my family vaccinated and protected.

I’ll be getting my flu vaccine, crossing my fingers that they are wrong, and hoping that a universal flu vaccine gets here much sooner than later.

Even if they are right and one strain is mismatched, I understand that being vaccinated is the best protection against the flu and still provides many benefits, including the chance for milder symptoms and less severe disease.

And I know that the only true fail here, in addition to pushing misinformation about flu vaccines, is in skipping a yearly flu vaccine.

More on This Season’s Flu Shot