Monday, February 11, 2008

Ineffective Flu Shot?

Did you give your kids the flu shot? It may have been all for nothing. I often wonder if the strain of flu in the shot is the right one. There are a lot of strains. Several doctors I have interviewed have said when referring to immunization shots you have to look at the risks versus the benefits. Most doctors believe the risks outweigh the benefits when it comes to childhood immunization shots, but some of them are not as adament about the flu shot. I found the following article on MSNBC saying this year the flu shot may not be as effective as you think.

The influenza vaccine given to Americans may not protect as well as expected, U.S. health officials said as the number of flu cases increase nationwide.

The U.S. Centers for Disease Control and Prevention said slightly more than half of the influenza virus strains reported to its surveillance system are not good matches against the strains included in this flu season’s vaccine.

The number of states reporting widespread flu activity jumped to 31 last week compared with 11 the week before, the CDC said. But Dr. Joe Bresee of the CDC’s influenza division said there are no indications this flu season is worse than usual.

“Seasonal flu activity was slow to start this year but has increased sharply in recent weeks,” Bresee told reporters.

One measure officials use to gauge the severity of the season is the number of flu-related child deaths. Bresee said the CDC has heard of six U.S. children who have died from the flu, a relatively low number compared with recent years.

Flu viruses mutate and change all the time, so every year a different vaccine is created as officials predict which particular strains will circulate.

The vaccine is designed to protect against three influenza strains — two from Type A, an H1N1 and an H3N2 version, and one for Type B.

Bresee said about 30 percent of the overall strains of influenza in the United States may be a Type A strain that emerged in Australia called H3N2 A/Brisbane. It emerged too late to be included in the flu vaccine offered in the United States beginning in September and October.

The Type B strain chosen for this year’s vaccine also was not a good match for most of the B virus strains seen in the United States this flu season, Bresee said.

“While a less-than-ideal virus match between the viruses in the vaccine and those circulating viruses can reduce vaccine effectiveness, we know from past influenza studies that the vaccine can still protect enough to make illness milder or prevent flu-related complications,” Bresee said.

Bresee noted that decisions on the composition of the annual vaccine are made about nine months before it is made available to the public in the fall, and it is sometimes hard to know that far in advance which strains will circulate.

Flu vaccines take months to make.Bresee also said some resistance is being reported to the antiviral drug Tamiflu, made by Switzerland’s Roche Holding AG and Gilead Sciences Inc of the United States. Of the viruses tested in CDC flu labs, 4.5 percent are resistant to the drug, Bresee said.

Influenza kills an estimated 36,000 Americans in an average year, and puts 200,000 into the hospital, the CDC said.


NewsAnchorMom Jen


Anon E. Mouse said...

Got my flu shot and get it every year. I really think it is some of the best return on the dollar investment I make.

Knight in Dragonland said...

OK ... in the body of your post you say "less effective." In the MSNBC article, the expert quoted says "less effective." Why then is the title of this post "Ineffective Flu Shot?" That puts an unnecessarily sensationalist negative spin on this piece of news that's not going to help my job any.

Even when there is a strain mismatch, the vaccine remains effective. Certainly it is less effective, but there is enough similarity between the strains to provide some level of protection. It will still prevent some cases of flu from mismatched strains, and those that break through will be less severe.

If 30% of the A strains are mismatched, then that means 70% are matched to the vaccine. Influenza B represents a small fraction of the total number of flu cases, and it does not have the pandemic potential of flu A.

There is also cumulative immunity. People who get their influenza vaccine every year (as I do) are provided an additional level of protection because their immune memory is being reinforced regularly to battle the flu.

Certainly this is not good news. The last time we had a significant mismatch was 2003-2004, and that was a bad flu season. I was hoping that a late season meant a mild season, but it's looking like that's not going to be the case.

If anything this news should be reason for MORE people to get immunized, not less. The best protection would be a greater herd immunity. The more people who are immunized, the less chance an infection has to become established within the community.

Any physician who is luke-warm about the flu shot is doing their patients - and the entire community - a disservice. Pertussis killed about 8000 per year at its height in the 1940s. Flu continues to kill 3-5 times that number annually. Why would a doc press for the DTaP and Tdap vaccines but not the influenza vaccine? Pertussis remains a problem that is best addressed by vaccination, but flu is the clear and present danger here.

I realize it's a hard sell to encourage a vaccine that needs to be renewed annually and for which there is already a negative stigma - but that's no excuse. Influenza kills way too many people for the medical community to be complacent. said...

Knight in Dragonland,
I put Ineffective Flu Shot? I think the "question mark" makes the title work. Several doctors I have talked to do question the effectiveness of the flu shot, including Dr. Bennett Leventhal, who is very pro-vaccinations.

Keely said...

I think we should seriously question the effectiveness of all routine and selective vaccinations. Do we really need them? How effective are they? How do we know? As I continue to do more research into vaccines, I become more angry that I allowed my children to be vaccinated without question. I just signed up for an online workshop so that I can understand more about the effectiveness of vaccinations. You may be interested in checking it out too. It is called Childhood Vaccinations: Questions Every Parent Should Ask. called Childhood Vaccinations: Questions Every Parent Should Ask.

Diane Vespa said...

I shudder to think what could happen if every parent suddenly took a negative view of immunizations and quit immunizing their children. Wouldn't that put us back to where we were 100 years ago, with children dying in droves from preventable childhood disease?

It seems that even one non-immunized child could put everyone around him at risk. I have yet to meet a pediatrician that does not endorse immunization. I'm not saying they aren't out there.. I've just never met one!

dayoub said...

flu vaccine is a a marginal public health policy.

Where do I begin. Sadly young doctors are totally brainwashed about the effectiveness of flu vaccines.

There are NOT 36,000 annual deaths from the flu. This is a lie. It is based upon a mathematical equation the CDC uses and has NEVER been validated. According the CDC's National Vital Statistics the actual death numbers are less than 2,000, sometimes well below 500 per year. If you break it down by age group you will see that about 5 kids die annually and 1 woman of child bearing age annually on average. In other words, rare deaths. And these are deaths with viral lab confirmation only, no idea if they died with a colonized virus (just living in the airway without causing disease state) and therefore did not contribute to the death. No mention of what infections were caused by immunocompromised states, etc. If you compare the reported number of deaths FROM a flu shot listed on the FDA's VAERS it is easy to confirm that more children and adults die from the flu shot than from influenza infection!

As for effectiveness, only about 10-12% of viral cultures test positive for ANY influenza strain in cases of "influenza-like" illness. Other viruses are more dominant than influenza. So the vaccine cannot possibly be more than 10-12% effective at preventing flu illness. Second, the antigenic match is 50% (in the years I checked) so now you are down to 5-6% effective. FInally as few as 60% of individuals who get a flu shot fail to develop adequate antibodies, so it is worthless.

Don't believe my math? Ok How about some publications: 3 studies in the last year failed to show reduction in deaths and/or illnesses in the general population. Email me and I will send them to you. My favorite study was from Toronto. After $42 million dollars to triple vaccine coverage rates in Ontario, the admission rates and illness rates increased! ANother study showed that annual flu vaccine coverage rates increased and mortality increased? A disconnect maybe?

I published a paper on the flu vaccine and pregnancy, you may get a free copy here:

Lots of fear-mongering for a billion dollar industry.
Want to prevent the flu? Try Vitamin D as there is ample evidence that flu is seasonal in the winter months because of a drop in Vit D levels. You will need at least 1,000 U per day, preferably 2,000 IU. We give our kids 1,000 daily and no sniffles for the last 2 years!

d ayoub, md

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