Re: Is there still a chance for us? (question ?)

Date: Wed Sep 26 2001 - 12:29:05 MDT

James Rogers wrote:
> It is possible that you already have immunity. The smallpox vaccine is
> based on the cowpox virus (hence the word "vaccine"), and if you worked on a
> farm as a child you may have already been exposed to it.

Actually the smallpox virus is based on the vaccinia virus, which is
where the word "vaccine" comes from. The medical name for the smallpox
virus is variola.

Vaccinia and variola are part of a family of viruses known as Orthopox
viruses. These also include monkeypox and cowpox. There is a related
family called Avipox viruses which affect birds. Researchers who work
with these types of viruses have been the only ones able to get smallpox
vaccinations in recent years. provides a good
description of the symptoms of smallpox and its progression:

   Symptoms of smallpox begin 12--14 days (range: 7--17) after exposure,
   starting with a 2--3 day prodrome of high fever, malaise, and
   prostration with severe headache and backache. This preeruptive
   stage is followed by the appearance of a maculopapular rash (i.e.,
   eruptive stage) that progresses to papules 1--2 days after the rash
   appears; vesicles appear on the fourth or fifth day; pustules appear
   by the seventh day; and scab lesions appear on the fourteenth day
   (Figures 1,2) (3). The rash appears first on the oral mucosa, face,
   and forearms, then spreads to the trunk and legs (3,4). Lesions
   might erupt on the palms and soles as well. Smallpox skin lesions
   are deeply embedded in the dermis and feel like firm round objects
   embedded in the skin. As the skin lesions heal, the scabs separate and
   pitted scarring gradually develops (Figure 2) (4). Smallpox patients
   are most infectious during the first week of the rash when the oral
   mucosa lesions ulcerate and release substantial amounts of virus into
   the saliva. A patient is no longer infectious after all scabs have
   separated (i.e., 3--4 weeks after the onset of the rash).

I have been told that emergency workers at hospitals have been given
lists of symptoms of smallpox and other biological warfare agents so
that an attack can be recognized as early as possible. Here is a description
from the article above of procedures in response to a smallpox attack:

   If an intentional release of smallpox (variola) virus does occur,
   vaccinia vaccine will be recommended for certain groups. Groups for
   whom vaccination would be indicated include

        persons who were exposed to the initial release of the virus;

        persons who had face-to-face, household, or close-proximity
        contact (<6.5 feet or 2 meters) (84) with a confirmed or suspected
        smallpox patient at any time from the onset of the patient's
        fever until all scabs have separated;

        personnel involved in the direct medical or public health
        evaluation, care, or transportation of confirmed or suspected
        smallpox patients;

        laboratory personnel involved in the collection or processing
        of clinical specimens from confirmed or suspected smallpox
        patients; and

        other persons who have an increased likelihood of contact with
        infectious materials from a smallpox patient (e.g., personnel
        responsible for medical waste disposal, linen disposal or
        disinfection, and room disinfection in a facility where smallpox
        patients are present).

   Using recently vaccinated personnel (i.e., <3 years) for patient care
   activities would be the best practice. However, because recommendations
   for routine smallpox vaccination in the United States were rescinded
   in 1971 and smallpox vaccination is currently recommended only
   for specific groups (see Routine Nonemergency Vaccine Use), having
   recently vaccinated personnel available in the early stages of a
   smallpox emergency would be unlikely. Smallpox vaccine can prevent
   or decrease the severity of clinical disease, even when administered
   3--4 days after exposure to the smallpox virus (2,4,85). Preferably,
   healthy persons with no contraindications to vaccination, who can
   be vaccinated immediately before patient contact or very soon after
   patient contact (i.e., <3 days), should be selected for patient care
   activities or activities involving potentially infectious materials.
   Persons who have received a previous vaccination (i.e., childhood
   vaccination or vaccination >3 years before) against smallpox might
   demonstrate a more accelerated immune response after revaccination
   than those receiving a primary vaccination (3). If possible, these
   persons should be revaccinated and assigned to patient care activities
   in the early stages of a smallpox outbreak until additional personnel
   can be successfully vaccinated.

So the good news is that emergency administration of the vaccine
immediately after exposure can reduce symptoms, and that people over 35
or so who have been previously vaccinated will respond especially well
to revaccination.

Bad news aplenty is available from the New Scientist's series on bioterrorism
at A
supposedly reassuring article,,

   THE US already has enough smallpox vaccine to defeat most bioterrorist
   attacks with this virus, according to public health officials. Between
   six and seven million people could be treated by the amount of vaccine
   that is currently in the country's stockpiles.

but then continues,

   Meltzer constructed various models based on the number of people
   infected in the attack, and how many other people each of these
   can infect. His model predicts that between three and nine million
   vaccinations would be enough to contain an initial outbreak affecting
   a hundred people, but only if at least a third of those infected were
   put in quarantine as soon as they developed the symptoms.

So we have plenty of doses - as long as only a hundred people were
initially exposed! And even then we need millions of vaccinations to
handle the outbreak! This is devastating news because one would suppose
that the kinds of terrorists we are dealing with today would be able to
infect far more people than this.

The latest bit of sunshine on the New Scientists site comes from

   The prospect of an anthrax attack was investigated in the 1990s
   by the US Office of Technological Assessment. They concluded that
   100 kilograms of virulent anthrax effectively dispersed at night
   over Washington DC could cause between one and three million
   deaths. Crop-dusters can carry up to twice that capacity.

It's very bad news.


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