Government will track side effects of mass swine-flu vaccinations

WASHINGTON (AP) — More than 3,000 people a day have a heart attack. If you’re one of them the day after your swine-flu shot, will you worry the vaccine was to blame and not the more likely culprit, all those burgers and fries?

The government is starting an unprecedented system to track possible side effects as mass flu vaccinations begin next month.

The idea is to detect any rare but real problems quickly, and explain the inevitable coincidences that are sure to cause some false alarms.

“Every day, bad things happen to people. When you vaccinate a lot of people in a short period of time, some of those things are going to happen to some people by chance alone,” said Dr. Daniel Salmon, a vaccine safety specialist at the Department of Health and Human Services.

Health authorities hope to vaccinate well over half the population in just a few months against swine flu, which doctors call the 2009 H1N1 strain.

That would be a feat. No more than 100 million Americans usually get vaccinated against regular winter flu, and never in such a short period.

How many will race for the vaccine depends partly on confidence in its safety. The last mass inoculations against a different swine flu, in 1976, were marred by reports of a rare paralyzing condition, Guillain-Barre syndrome.

So the CDC is racing to compile a list of what’s normal: 25,000 heart attacks every week; 14,000 to 19,000 miscarriages every week; 300 severe allergic reactions called anaphylaxis every week.

Any spike would mean fast checking to see if the vaccine really seems to increase risk and by how much, so health officials could issue appropriate warnings.

Very rare side effects by definition could come to light only after large-scale inoculations begin — making this the year scientists may finally learn if flu vaccine truly is linked to Guillain-Barre, an often reversible but sometimes fatal paralysis.

It’s believed to strike between one and two of every 100,000 people. It often occurs right after another infection, such as food poisoning or even influenza.

But the vaccine concern stems from 1976, when 500 cases were reported among the 45 million people vaccinated against that year’s swine flu.

Scientists never could prove if the vaccine really caused the extra risk. The CDC maintains that if the regular winter flu vaccine is related, the risk is no more than a single case per million vaccinated.