Saturday, January 24, 2015

Why do so few European countries recommend flu shots for children?/

The data below come from:  Eurosurveillance, Volume 19, Issue 16, 24 April 2014
Few European countries recommend flu shots for children, and  only 3 suggest them for all children above 6 months old, as does the US. Most countries recommend them only for elders, the group most likely to die from flu.  However, elders are the least likely age group to develop meaningful immunity from the shots.

A 2012 Cochrane review of flu vaccination in children had this to say:
Extensive evidence of reporting bias of safety outcomes from trials of live attenuated influenza vaccines (LAIVs) impeded meaningful analysis... 
It was surprising to find only one study of inactivated vaccine in children under two years, given current recommendations to vaccinate healthy children from six months of age in the USA, Canada, parts of Europe and Australia. If immunisation in children is to be recommended as a public health policy, large-scale studies assessing important outcomes, and directly comparing vaccine types are urgently required... 
The review showed that reliable evidence on influenza vaccines is thin but there is evidence of widespread manipulation of conclusions and spurious notoriety of the studies. The content and conclusions of this review should be interpreted in the light of this finding.”
Here is the table of how European countries recommend flu vaccines:

Remember that most of the countries listed have better mortality rates and better health indices, in general, than the US. Most have national health programs.  Most of these health departments probably know that the benefit of flu vaccine is marginal in healthy children, and the risk is unknown (due to poor quality data). This year, CDC estimated flu vaccine efficacy to be 23%, based on the following:  of a group that did not get flu, 56% were vaccinated, while in a group that got flu, 49% were vaccinated.

But CDC acknowledges the data are not terribly reliable:
The findings in this report are subject to at least four limitations. First, these early VE estimates are imprecise for persons aged ≥18 years, limiting ability to detect statistically significant protection against influenza illness resulting in visits to health care providers; larger numbers of enrollees are required to detect significant protection when VE is low. Second, the VE estimates in this report are limited to the prevention of outpatient medical visits, rather than more severe illness outcomes, such as hospitalization or death; studies are being conducted during the 2014–15 season to estimate VE against more severe illness outcomes. Third, vaccination status included self-report at four of five sites, and dates of vaccination and vaccine formulation were available only for persons with documented vaccination obtained from medical records or immunization registries; complete vaccination data are needed to verify vaccination status and estimate VE for different vaccine formulations. Finally, future interim estimates and end-of-season VE estimates could differ from current estimates as additional patient data become available or if there is a change in circulating viruses late in the season.
So just in case, CDC recommends you get a flu shot and a dose of Tamiflu as soon as you get sick.


Anonymous said...

Dear Dr. Nass

A recent article stated; "The company in question is Meriden-based Protein Sciences. It’s the only American company that makes a flu vaccine in the U.S.".

And another article in the Wall Street Journal states that there are only seven vaccine manufactures of the flu vaccine distributed within the U.S..

If these things are true then it would seem likely that a percentage of the flu vaccine is produced over seas. My question is regarding the vaccines produced overseas would the FDA have oversight of the Labs that produce the flu vaccines imported and produced in Labs overseas?

Thank You

Meryl Nass, M.D. said...

Here is a chart with the seven flu manufacturers and the different types of vaccines they make that are sold in the US:

FDA has jurisdiction over all drugs that are licensed and sold in the US. They are responsible for reviewing data and performing inspections anywhere in the world drugs and vaccines are made.

That said, FDA has relatively small offices overseas. Before the scandal involving deaths due to heparin made in China, FDA had no permanent office in China to inspect the hundreds of products made there. So foreign manufacturers probably experience fewer FDA inspections than their US counterparts.