the data available to the Vaccine Advisory Committee are accurate, and
provide clear choices for selecting the "right" three strains
to include in the vaccine. More
often, those data are extremely complex and puzzling. Still, the panel
manages to make many accurate decisions, so the vaccine they recommend
offers good protection from the most serious and common flu strains
the following year. Given the complexity of the data, and the amount
of uncertainty about which strains will spread, the panel's success
rate is remarkably high. But of course, when a vaccine works as people
expect it to, that success is generally taken for granted.
the data are either so contradictory or so confusing that even the best
and brightest infectious disease specialists in the country can't find
three clear "winners." When this happens, the panel must make
what amount to highly educated guesses. Sometimes they guess right
and sometimes they don't. As a result, some years, the recommended vaccines
offer little or no protection against the most serious strain (or strains)
in U.S. And, of course, given the way the media and the public think,
it is these occasional "goofs" that people pay most attention
other times, the "right" choices for the vaccine may be clear,
but practical difficulties complicate the panel's decision. That was the case for the 2003-2004 flu
season. Here's what happened.
gathered for the 2003-2004 season vaccine identified a strain from China called the Fujian strain after the region
from which it was first reported. This strain looked dangerous. It was
a member of the Influenza Type A H3N2 class of viruses, which often
cause severe illness and death.
It had hit Japan and Korea in 2002, and cause the largest outbreak
in Australia in five years.
vaccine manufacturers experienced major problems with this strain. They
couldn't get it to grow in eggs, and were worried that they wouldn't
be able to produce enough of it to include in the vaccine. Most committee
members agreed that an alternative way of growing this strain (in a
culture of dog cells) posed significant risks. So they were faced with
a very difficult choice.
could recommend that the Fujian strain be included in the vaccine
knowing that difficulties in producing it could mean that there would
be no vaccine available at all.
the other hand, they could recommend making the vaccine with a close
relative, known as the Panama strain. That strain could be produced
reliably, and it seems similar enough to the Fujian strain to offer
at least some protection.
was a very difficult position. The committee delayed a decision as long
as possible until March. But manufacturers still couldnšt grow
the Fujian strain quickly enough. When the committee finally had to
decide, 17 out of 18 members voted to recommend the Panama strain. Most
of them were distressed about that forced decision.
As it turned out, their distress was justified.