smallpox vaccine and vaccination in the intensified ... - libdoc.who.int

lengthy process, sometimes more than a year
elapsing between the submission of a sample
and the sending of a report on its potency to
the producer. Two factors contributed to this
delay. First, the testing arrangements were
entrusted as additional work to the small
Biological Standardization unit of WHO,
whose normal duties involved the staff in
frequent absences from Geneva; samples for
testing and reports on potency had to await
their return from duty travel. Secondly, the
testing was carried out for WHO by the State
Serum Institute in Copenhagen, which pro-
duced smallpox vaccine on a relatively small
scale and for only a brief period each year; to
rationalize its work, it usually tested samples
from WHO at the same time as its own local
production batches. This delay, which was
unacceptable if the assays of vaccine quality
were to be of any use, was eliminated when
the responsibility for testing was transferred
to the WHO reference centres for smallpox
vaccine and the handling of samples and
reports in Geneva was taken over by the
Smallpox Eradication unit.
After 1968, all producers who donated
vaccine to the eradication programme or who
produced vaccine for national eradication
programmes were requested to submit vac-
cine samples periodically for testing by WHO.
In addition, laboratories developing the ca-
pacity to produce freeze-dried vaccine were
encouraged to submit samples to WHO for
testing, so that they could be advised, if
necessary, on how to improve the quality of
their vaccine. Between 1967 and 1984, 27
countries donated freeze-dried vaccine to
WHO (see Table 11.1 5). Samples of all these
donations were sent to WHO reference
centres for testing. At later stages of the
programme, when samples from producers
consistently met WHO requirements, dona-
tions were accepted without advance testing,
although samples were tested after the dona-
tion had been received, to confirm that it was
of the desired quality.
For the quality control of vaccine produced
locally in endemic countries, WHO smallpox
eradication staff working for national pro-
grammes were actively involved in collecting
and dispatching vaccine samples and, if the
results of the assays carried out by the national
laboratorv and the WHO International Refer-
ence Centre were in agreement, the batches
of vaccine from which the samples had
been taken were dispatched for use in the
field.
11. VACCINATION IN THE INTENSIFIED PROGRAMME 555
Plate 11.8. Nelja N. Maltseva (b. 1934). a member
of the WHO collaborating centre in the Moscow
Research Institute for Viral Preparations. USSR.
was active in laboratory diagnosis and research and
worked as a consultant on vaccine production in
several countries.
Visits by Consultants
Vaccine producers having problems in
ensuring that vaccine quality met WHO
requirements, starting new methods of production
or modifying traditional production
methods were encouraged to benefit from the
advice of visiting " WHO short-terk consultants.
Although many laboratories were engaged
in vaccine production, only a few of the
~ersonnel concerned were suflicientlv , exDer- L
ienced to be able to suggest realistic improvements
in production methods, since instruments
and working procedures had to be
adapted to the prac~ical realities in developing
countries. The 15 consultants and the
countries they assisted are listed in Table 11.9.
Over the period 1967-1979 they visited more
than 20 laboratories.
Freeze-driers manufactured by Edwards
High Vacuum, Crawley, Sussex, England,
were widely used and, at the request of the
Smallpox Eradication unit, technicians from
this company visited producers to maintain
and service equipment.
Reference Vaccine
The International Reference Preparation
of Smallpox Vaccine was established in 1962