Yesterday I breathed a sigh of relief as I watched my teenage daughter get her H1N1 shot at a local public health clinic. Though she grumbled as I dragged her across town during her lunch period, she couldn't help smiling when she saw it was a girlfriend's mom, a volunteer nurse, administering the shots.

In fact, there was such an upbeat community spirit around the event--organized in the meeting room of a local arts center--that I half expected someone to break out doughnuts.

We'd arrived early after getting a heads-up from the town health officer that within 24 hours of his announcing the four-hour clinic, he had received hundreds of calls from as far as two states away. Yet it was so well organized that my daughter was in and out and back to high school with 15 minutes of her lunch period to spare.

Meanwhile, on Nov. 3, CDC officials announced the availability of another 31.8 million doses of H1N1 vaccine, bringing the total doses available for distribution to 10 million. This remains short of the national need, but should make headway in vaccinating high-priority groups such as pregnant women, children and young adults, and those with underlying health problems such as asthma or heart disease.

As the ranks of the vaccinated expand well into the millions this week, health officials also expect the inevitable. After being immunized, some people will suffer health problems for reasons that have nothing to do with the vaccine. For decades, the tendency to link such events to immunization has plagued childhood vaccination programs.

As a proactive measure, an international team of epidemiologists, immunologists, and infectious-disease specialists has published a report in the medical journal Lancet, cataloging the background rates of disorders that they suspect could be erroneously linked with vaccination. Their statistics include the following:

• Miscarriage occurs in around 400 in a million pregnant women in any given day.

• Guillain-Barré paralysis occurs in around 4 in 10 million persons in any given week.  

• Sudden unexplained death occurs in 5 or 6 per 10 million persons in any six-week period.

Only if rates spike above these numbers, the researchers say, should any potential link to vaccination be proposed.

And now that I have my daughter's H1N1 shot checked off, I'm resuming my hunt for seasonal flu vaccine in our area. So far, no luck.

Science journalist Jessica Snyder Sachs is the author of Good Germs, Bad Germs: Health and Survival in a Bacterial World. Got a question or comment about swine flu? Post it here. Throughout the flu season, Jessica will be answering your questions on all things influenza.