POST00392E
A "THINK PIECE" ON INTRODUCTION OF NEW VACCINE: BALANCING PUBLIC DESIRE FOR
THE VACCINE WITH OPERATIONAL DIFFICULTIES RELATED TO CATCHUP PLANS
26 November 2001
In Post00373, 10 September 2001, Robert Steinglass from BASICS
, contributed a thought provoking paper: "How to
introduce new combination vaccines (tetravalent and pentavalent): some
practical and ethical questions".
In Post00375, 18 September 2001, Alan Schnur from WHO
, contributed to the discussion, pointing out that
there are cost, training and logistics implications for this policy to
provide full hepatitis B immunization to the "first" cohort. Alan said that
he would submit that the ethical and programmatic considerations of sending
children away from our immunization sessions only partially immunized must
also be considered.
In Post00382, 9 October 2001, John Lloyd from PATH
explained the EPI policy, while Dianne Phillips from Department of health,
South Africa
explained South Africa's policy and the
reasons for it. Anthony Battersby pointed out the need
for operational planning and a variety of vaccine presentations when new
vaccines are introduced.
In today's posting, Jay Wenger from WHO underlines that
the decision taken will vary depending on the operational status of a
country's immunization programme and the specific ethical settings:
"Robert has nicely summarized important issues relevant to deciding who
should actually receive new antigen at the time of introduction of
combination. The views below result from different decisions on these
questions. I think the decision taken will vary depending on the operational
status of a country's immunization program, and the specific ethical
settings.
In discussions with various EPI managers in some less developed (than China)
countries, although options including the below have all been discussed:
1. Partial Catchup with new antigen (sort of like described by Allan),
requiring coexisting (in the fridge) monovalent new antigen (or two new
antigens, if doing pentavalent), as well as DTP-combo.
2. Completion of schedule initiated at first visit (Roberts straw person
description), requiring coexisting DTP and DTP-combo.
3. Abrupt intro method at defined date (one of Johns options), requiring
only DTP-combo, with abrupt stop of DTP, and resulting in incoming cohort
fulling immunized with new vaccine, and those children who had already
started DTP being partially immunized for new antigens.
In general, the 3rd option has been selected. Our approach has been to
discuss these options in the specific country context, and come up with
something country appropriate.
Tied up in these discussions are the impact of these different introduction
techniques on disease. For Hib, it is clear that introduction with catchup
(all the way up to 5 years of age) is the most rapid way to decrease disease
burden, resulting in drastic drops in cases within 1 year, compared with 2
years for immunization of the incoming cohort alone. However, these data are
from the Americas and western Europe, where the disease age distribution is
much higher than in countries now considering introduction, where most
disease occurs in children less than 1, and thus, the importance on impact
of disease is less, and the issue is primarily one of public acceptability,
and not impact of the vaccine. For HepB, there will be no discernable
difference in any measurable parameter of disease burden, but the issue of
public acceptability remains. Thus, for both these vaccines, the decision
may come down to balancing public desire for the vaccine with operational
difficulties related to catchup plans."
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