When the first swine flu vaccinations begin being given to the general public in just a few weeks, there will be some people who get them that will have strokes or heart attacks. Some pregnant women may miscarry, and some children may have seizures. However, officials are warning that these events will not necessarily have anything to do with the flu vaccine.

Federal officials are aware of the potential public relations challenges, recalling how sensational reports of death and illness thwarted the large-scale swine flu vaccine drive of 1976. This time, however, they are prepared and have begun making plans to quickly respond to such events to reassure the wary public that the vaccine is not the culprit.

It is important to keep in mind that each year 200,000 Americans will have their first seizure, and there are 1.1 million heart attacks, 795,000 strokes and 876,000 miscarriages. Some of these will inevitably occur within hours or days of receiving a flu shot.

Dr. Harvey V. Fineberg says that the government "is right to expect coincident deaths, since people are dying every day, with or without flu shots." Fineberg is the president of the Institute of Medicine, and co-author of "The Epidemic That Never Was", a book on the history of the 1976 swine flu vaccination drive.

Back in 1976 during the first days of the flu vaccine campaign, three elderly Pittsburgh residents died shortly after receiving their shots at the same clinic. Scientists believe that it was a freak coincidence, but newspapers suggested that the shot had killed them. The vaccination campaign eventually vaccinated 45 million Americans.

Reports also later emerged of some vaccine recipients suffering from Guillain-Barré, which is when the body's immune system attacks the nerves, leading to temporary or permanent paralysis, and in some cases, death. After this, officials ended the campaign to investigate. To this day, experts disagree over whether the vaccine caused the number of cases to increase that year. This time, the CDC will be on high alert for reports of it.

The actual cause of Guillain-Barré’s is not known. Different studies, however, have suggested that it more often affects those who have had a flu shot, the flu itself, some bacterial infections, and people struck by lightning.

Once the 1976 campaign was suspended, there was no need to restart it as the predicted epidemic never occurred. OFficials say that this time it's different. The 1976 virus died out during the previous winter before any vaccine was made, but this time the H1N1 virus has already infected millions, and if unchecked, will affect over two billion worldwide, claims the World Health Organization.

100 million Americans get annual flu shots this year, and the government has ordered nearly 200 million doses of the swine flu shot.