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Plans are underway to stretch existing smallpox vaccine doses to cover three or even five times as many people. This stopgap measure is of critical importance. The only way to stop a smallpox outbreak is to vaccinate a ring of people who have been around infected people.
People with smallpox are contagious only after they begin to get the awful rash that gives the disease its name. This means that once an outbreak is known to be under way, people with the rash are unlikely to infect anybody except for caregivers. These are the people who first should get the vaccine.
During very small outbreaks, patients can be kept in isolated hospital rooms. In larger outbreaks, patients would have to be kept at home. In either case, limited vaccine supplies would be rationed to the people surrounding each case. This strategy worked in previous outbreaks prior to smallpox eradication. Even then -- when most of the population had been vaccinated as children -- there was terrific pressure for mass vaccinations. Controlling mass panic is the most troublesome aspect of dealing with a smallpox attack. If sufficient vaccine is not on hand, some experts fear that the government will have no option other than forcible quarantine of exposed people.
Once the U.S. government has its 300 million doses of smallpox vaccine, the question is what to do with it. Some experts favor routine vaccination for everyone preemptively; others would reserve the vaccine to use only in the event of an outbreak.
The smallpox vaccination isn't completely safe. In the U.S. in 1968, for example, some 14 million people received the vaccine. That year there were 572 bad reactions resulting in nine deaths -- more people than have died so far in the current anthrax bioterror attack. In those days, bad reactions were treated with serum (a component of blood) from people who recovered from infection with smallpox -- and now this serum is in very short supply.
Unknown is what effect vaccination might have on people whose immune system isn't working right -- such as those with HIV infection or those taking immune-suppressing drugs for arthritis. Pregnant women also are at increased risk of bad reactions to vaccination. However, these populations also would be at increased risk of fatal smallpox -- so the risk of vaccination would have to be weighed against the risk of infection.