Smallpox vaccine policy: the national debate - Health Policy Update - dangers of smallpox as biological weapon trigger vaccination policy debate

Physician Executive, Sept-Oct, 2002 by Georges C. Benjamin

Recent concern about the criminal use of smallpox as a biological weapon stimulated discussion about rein-stituting a national smallpox vaccination program.

There is general agreement that some degree of revaccination is warranted. However, the size and scope of such a program is unclear. Whatever is decided, this is the first phase of an intense public health policy debate concerning how best to protect the American people from harm by a smallpox attack.

A disease from the past

Smallpox has been known as a significant public health threat since Pharaoh Ramses V died in 1157 BC.

Centuries later, a global campaign through the World Health Organization (WHO) to eliminate smallpox killed it off as a naturally occurring disease in 1977 in Somalia. When the world was certified smallpox free in 1980, it was an accomplishment of monumental proportions.

Prior eradication of the disease in the United States allowed for the elimination of routine vaccination in the United States as early as 1972. The last outbreak occurred in New York City in 1947.

While there may be some residual immunity from prior vaccination, its effectiveness remains uncertain in those vaccinated over 20 years ago, and in general, most communities are preparing as though all are susceptible.

Until recently, there was not enough vaccine to make vaccination a realistic option for large populations. Recent efforts from federal officials increased the availability of smallpox vaccine making the prospects of vaccinating a large population a viable option to prevent and contain a potential outbreak should the risk return.

The concern returns

The anthrax attacks of October 2001 forced public health officials to reevaluate the risk to the public of acquiring a broad range of threat agents from a purposeful release.

Smallpox is the agent of greatest concern today and is undergoing the closest scrutiny because, unlike anthrax, it is contagious and would present a scenario quite different from the anthrax attacks.

The Advisory Committee on Immunization Practices (ACIP), the group that advises the federal government on the use of immunizations, recently made recommendations to the director of the U.S. Centers for Disease Control and Prevention (CDC) on the use of vaccinia vaccine.

This expands the ACIP's previous recommendation to only vaccinate laboratory workers who directly handle vaccinia or other orthopox virus.

Vaccinia vaccine, a live orthopox virus vaccine, is highly effective against smallpox if given pre-exposure and can result in a reduction in the incidence of disease or in disease morbidity/mortality if given within four days of exposure.

Vaccinia vaccine is not without risks. It can result in both death and disability in a small number of people. Data from prior studies and experience show 1,254 complications per 1 million primary vaccinations. (1)

In addition, there is 1 death per million vaccinations. These data predate the nation's recent experience with HIV/ATDS and the large number of immunocompromised individuals who receive cancer chemotherapy, organ transplantation or have other reasons for low immunity. Many believe that there would be far more individuals today that are at risk of severe complications of disease or vaccine.

The ACIP recommendation is an attempt to balance the risk of the vaccine in an environment where there is an absence of any confirmed smallpox and the risk assessment for an attack using smallpox is low. The ACIP recommendation states: (2)

"Under current circumstances, with no confirmed smallpox and the risk of an attack assessed as low, vaccination of the general population is not recommended, as the potential benefits of vaccination do not outweigh the risks of vaccine complications.

"Smallpox vaccination is recommended for persons pre-designated by the appropriate bioterrorism and public health authorities to conduct investigation and follow-up of initial smallpox cases that would necessitate direct patient contact.

"Smallpox vaccination is recommended for selected personnel in facilities pre-designated to serve as referral centers to provide care for the initial cases of smallpox. These facilities would be pre-designated by the appropriate bioterrorism and public health authorities, and personnel within these facilities would be designated by the hospital.

"Surveillance and containment, including ring vaccination, is the primary strategy for the control and containment of smallpox. In addition, state and local health departments would be able, if necessary, to expand immunization to additional groups, up to and including their own population, in a timely manner."

Vaccinating the entire population:

Some believe that a more practical approach is to vaccinate the entire population now.

Proponents of this position believe that vaccination now could be done in a more controlled manner with less risk to high risk populations and serve as an effective deterrent to a would-be attacker. (3)

They also point to a recent Harvard University/Robert Wood Johnson Foundation survey that found 59 percent of Americans would take the vaccine if it was made available. (4) This was despite knowing that the vaccine may produce serious side effects in a small number of cases.