Flu Vaccine Season Returns, With a Twist

With the H1N1 "swine flu" pandemic officially over - as of last week - WebMD reports that the CDC is gearing up for a seasonal flu vaccination campaign in September called "Flu Ends with U." Maybe the campaign will help clear up a heap of confusion about flu vaccines these days.

Part of the problem is that flu vaccination recommendations have changed substantially over the past few years. In 2010-2011, for the first time ever, the flu vaccine is recommended for everyone 6 months or older (anyone can have the flu shot, containing killed flu viruses; the flu nasal spray contains inactivated (modified) live flu viruses and is recommended for a smaller subset of people).

In 2009, the CDC recommended the seasonal flu vaccine only for children ages 6 months to 18 years, and adults ages 50 and over (with some exceptions for certain younger adults). In 2008, the flu vaccine was only recommended for children ages 6 months to 5 years old and adults 50 and over (with some exceptions).

The viruses that cause the flu are constantly mutating, and in response a new flu vaccine has to be developed each year, at least until researchers figure out how to make a universal flu vaccine that can provide long-term protection. Researchers make an educated guess about which three flu viruses will cause the most damage in the future, then modify the viruses to use them in vaccines by growing them, usually in chicken eggs, a time-consuming process. If a different flu virus spreads, the vaccine won't protect against it.

The WebMD article pointed out CDC focus group research that found that many people are not happy with the universal flu vaccination recommendations. Catching the flu is not a big deal to many people, but it can have serious consequences for some. On average, about 36,000 people die from flu complications each year, primarily the elderly. In 2009, about 12,000 Americans died from complications of swine flu, mostly those under age 65, according to the CDC.

The flu vaccinations recommendations have changed over the years to protect a wider range of people, and also to keep healthier people from catching and passing on the flu to others. It might be inconvenient to get flu vaccinations for the whole family, but it's still a good idea.

 
Resources:

• The CDC's 2010-2011 Vaccine Information Sheets contain information about both the flu shot and the flu nasal spray.
• Prevent the spread of disease by washing your hands when needed. The Mayo Clinic tells you when and how to wash your hands.

Is the H1N1 Vaccine Safe?

Is the H1N1 vaccine safe? I've heard this question a lot since I began promoting the book I co-authored, The Complete Idiot's Guide to Vaccinations. Young adults and mothers of young children tend to ask me about the H1N1 vaccine, because they are weighing the risks and benefits of getting vaccinated.

Modern vaccines are extremely safe. Problems such as bacterial contamination of vaccines, a serious threat several generations ago, has been largely eliminated through the use of preservatives and improved packaging. Many older vaccines have also been reformulated to reduce the risk of side effects (such as the old DTP vaccine, and the earlier rotavirus vaccine for children).

The H1N1 vaccine is made in the same way as the seasonal flu vaccine. The viruses that cause the flu are grown and biologically weakened in chicken cells, until they are still strong enough to create an immune system response in people, but too weak to cause the disease in a healthy person. Then the weakened viruses are either:

• killed and used in the seasonal or H1N1 flu shot (the best choice for people with weakened immune systems or other risks), or 
• kept alive and used in the seasonal or H1N1 flu nasal spray vaccine (the best choice for certain people with healthy immune systems).

The seasonal flu shot has been available since the middle of the last century; the nasal spray flu vaccine was licensed in the United States in 2003.

The CDC tracks health problems that might be linked to vaccines with the Vaccine Adverse Event Reporting System (VAERS). Both health care providers and the general public can report health problems that occurred after a vaccination to VAERS. Researchers monitor VAERS, looking for patterns of problems with a vaccine. If a pattern does occur, then they do further research within the Vaccine Safety Datalink (VSD), a database containing the health records from eight managed-care organizations across the country.

What have they found since they have been tracking the H1N1 flu vaccine? The CDC's Dec 11 Morbidity and Mortality Weekly Report (MMWR) found that the risk of serious side effects (adverse events) from the H1N1 vaccine is about the same as the risk for the seasonal vaccine. In a word: low. From October through November 2009, VAERS data showed 82 adverse events per million doses of H1N1, and 47 adverse events per million doses of seasonal flu vaccine.

Still, the rumors are flying about the H1N1 vaccine: that it can cause Gulf War Syndrome or Guillain-Barre syndrome, that it contains Agent Orange, and so on. The website FactCheck.org's "Inoculation Misinformation" article provides a good overview and rebuttal of some of the questions that have cropped up in emails and online about the H1N1 vaccine.

Google Flu Data Rivals CDC

Last week, internet search giant Google released the Google Flu Trends tool, which tracks possible flu outbreaks by compiling data on how often people use flu-related search terms such as "flu symptoms" and "chest congestion". Google Flu Trends provides raw data, but not context. Each year, close to 100 million Americans search for health information online, but not everyone who searches for health information is injured or ill. Since I write about medicine, for example, I usually search for health information online for my writing projects, not personal knowledge. Other searches, it seems, might be done out of idle curiosity, or even result from a keystroke error in the search bar.

Is Google Flu Trends just another odd little Google project that their employees tinker with at the Googleplex in Mountain View in between running the search engine and scanning in every book ever written? Apparently not. Google mapped five years' worth of their flu data against flu data from the Centers for Disease Control and Prevention (CDC), which the agency compiles from health care providers, emergency room visit statistics, and other sources. Data from Google correlated closely with CDC data, often predicting flu outbreaks a week or two before the CDC. Google will soon publish a paper on its methodology in an upcoming issue of Nature.

Health care researchers already search for trends in anonymized electronic medical records (EMRs) that some practices use to record patient medical data and prescriptions. More digital data will become available in the future as EMRs become more common (especially since the federal government is providing financial incentives for Medicare providers to adopt e-prescribing, starting in 2009) .

For various reasons, however, many patients are not entirely honest with their doctors about their symptoms and medical concerns, a problem health care providers have struggled with for years. A patient might be embarrassed about a medical problem, forget to mention a symptom, or simply not realize that a symptom is significant. For this reason, search engine data might provide an even larger, and potentially more accurate, data pool than EMRs to indicate the actual incidence of conditions such as pre-diabetes or early heart disease, for example. Public health officials could then use the data to create more effective screening and prevention campaigns.