http://www.cnn.com/2001/HEALTH/10/07/bioterror.vaccines.ap/index.html

Vaccinations against bioterror attacks?

October 7, 2001 Posted: 3:23 PM EDT (1923 GMT)

By Daniel Q. Haney
AP Medical Editor

(AP) -- Bioterrorists? Germ attacks? If the threat is real, why not roll up our sleeves and get vaccinated?

Vaccine experts say the question has come up often since September 11, and though certainly a reasonable one, many doubt population-wide shots will be a practical defense anytime soon against the deliberate release of deadly microbes.

The possible health hazards of mass vaccination could easily outweigh the benefits, they say, especially considering that no one really knows the likelihood of such a catastrophe. But beyond that are significant problems: No vaccines are available for civilian use except smallpox shots, which are in extremely short supply until at least next year; and the government's sole supplier of anthrax vaccine has failed to meet federal drug standards and isn't currently producing the vaccine.

But even if immunizing the entire U.S. population against terrorist bugs is unlikely, creating new and better vaccines is widely viewed as a key part of defense against bioterrorism.

For some potential terrorist weapons, such as smallpox and Ebola virus, there are no treatments at all. Anthrax and other bacteria can be treated with antibiotics, but in the case of anthrax, at least, treatment must begin rapidly. On Friday, a Florida man died of anthrax three days after being hospitalized, despite treatment with antibiotics. So vaccines that prevent infection entirely could be far more effective in the face of a large outbreak.

Even before the attacks on New York and Washington, developing vaccines against the A-list of bioterrorist weapons was high on the research agenda at the National Institutes of Health and the Defense Department.

In the works are vaccines against virtually every potential bioterrorist germ. Some might be given ahead of time to soldiers, hospital workers and police, but most would probably be held for distribution after an attack to stop further spread.

Scientists are seeking vaccines that could be produced rapidly and, once given, build up protection much more quickly than the standard shots now available.

Researchers who consult with government agencies speak of a new urgency there. "We suddenly realize, my God, we've got to deal with this," says Dr. Myron Levine, director of the University of Maryland's Center for Vaccine Development.

Health and Human Services Secretary Tommy Thompson said last week the government hopes to have 40 million fresh doses of smallpox vaccine by next summer, well ahead of the original deadline of 2004. Acambis, a British firm, will speed up its 20-year, $343 million program to replenish the U.S. supply. About 15 million doses of the old vaccine remain from the 1970s.

Smallpox was eradicated in 1977, and routine vaccinations ceased in 1980. However, the Russians produced tons of smallpox for their bioweapons program in the 1980s, and some experts fear some of it may have escaped, perhaps to other countries that make biological weapons.

About half of Americans alive today were vaccinated against smallpox, but the protection wears off. Dr. D.A. Henderson, director of the Johns Hopkins Center for Civilian Biodefense Studies, estimates that only 10 percent to 20 percent of them still have immunity against smallpox.

Acambis' new vaccine will be grown in cell cultures and will be much purer than the original version, derived from the pus of infected cows. The Centers for Disease Control and Prevention plans to store it at guarded warehouses around the country, to be shipped off quickly after an attack to keep the highly contagious and untreatable virus from spreading.

The plan: Quarantine areas where smallpox is seen, then vaccinate everyone who lives around them. Nine million doses of vaccine would be needed to contain an outbreak that begins with just 100 infected people.

The logistics are daunting, especially if people are infected in several cities. In 1947, it took a week to vaccinate 6 million people in New York City in response to an outbreak of eight cases.

So why not inoculate everyone as soon as a vaccine is available?

"It has to be re-examined. I am certainly beginning to think that may be a reasonable approach," says Dr. Ronald Atlas of the University of Louisville, president-elect of the American Society for Microbiology.

However, many specialists are dubious, including Henderson, who headed the global smallpox eradication campaign. Two years ago, he led a committee of government and academic specialists who rejected the idea, and that conclusion still stands.

"The answer is definitely no," says Henderson.

The main reason is the vaccine's safety. When smallpox was a true health hazard, those risks were small in comparison. But the equation changes when the threat cannot be measured. Experts contend that even a few hundred deaths or serious complications that are vaccine-related would be considered unacceptable.

About 3 in every 1 million people vaccinated would get encephalitis that may lead to death or permanent neurological damage, experts estimate. Another 250 would get a smallpox-like rash caused by vaccinia, the usually harmless virus used for the vaccine. The rash could be fatal if not treated.

People with weakened immune systems -- cancer and transplant patients, those taking high-dose steroids and people with AIDS -- could be especially susceptible. Even if left unvaccinated, they might catch vaccinia from those who are vaccinated.

Recently, British researchers announced they had deciphered the genetic blueprint of plague bacteria. The discovery could offer new hints for vaccine design. The current vaccine protects against the bubonic form of plague but not the inhaled variety, which is feared as a terrorist weapon.

Plague and other bacterial hazards, such as anthrax, can be treated with antibiotics. But medicines often must start soon after exposure, even before symptoms start, to be effective. Since there probably would be no warning of a germ attack and early symptoms could be mistaken for the flu, treatment might start too late for many. Nevertheless, some people have stocked up on prescription antibiotics, such as Cipro and doxycycline.

The current anthrax vaccine is reserved for the military, and experts seem unanimous that it is too cumbersome for civilian use. It requires six shots over 18 months, then yearly boosters. Add to that the fact that the vaccine's only U.S. maker, Bioport Corp., has not produced a vaccine since 1998 because of failing to meet Food and Drug Administration standards, the New York Times reported.

Several labs are doing government-financed research to find a better anthrax vaccine, which would eliminate the need for speedy antibiotics. One of them, Vaxin in Birmingham, Alabama, is working on a genetically engineered version that could be given with a skin patch.

While it might be aimed initially at soldiers or health workers, "vaccinating the entire population is not all that farfetched," says Kent Van Kampen, the company's president. But that vaccine is not expected to be available for three to five years.

If it or another new anthrax vaccine works out, the thinking about large-scale vaccination could change.

"If we had a great vaccine in enough quantity with no side effects and we felt the threat was large and imminent, that would be a reasonable question for public health discussion," said Johns Hopkins' Dr. Luciana Borio. "We do not have that."

Medical Editor Daniel Q. Haney is a special correspondent for The Associated Press.

ALL INFORMATION, DATA, AND MATERIAL CONTAINED, PRESENTED, OR PROVIDED HERE IS FOR GENERAL INFORMATION PURPOSES ONLY AND IS NOT TO BE CONSTRUED AS REFLECTING THE KNOWLEDGE OR OPINIONS OF THE PUBLISHER, AND IS NOT TO BE CONSTRUED OR INTENDED AS PROVIDING MEDICAL OR LEGAL ADVICE. THE DECISION WHETHER OR NOT TO VACCINATE IS AN IMPORTANT AND COMPLEX ISSUE AND SHOULD BE MADE BY YOU, AND YOU ALONE, IN CONSULTATION WITH YOUR HEALTH CARE PROVIDER.