LIVE POLIO IRUS VACCINES

Vaccination with Attenuated Polioviruses in Costa Rica
573
yet completed. A convalescent serum will be
necessary for a complete analysis of the case.
Cases Nos. 303 and 304. The stool data are
not yet available, and results on the acute serum
only are not sufficient to establish a diagnosis.
However, the serologic data indicate lack of
response in Case No. 303 to Types 1 and 2 vaccine,
and in Case No. 304 to Type 1 vaccine.
The vaccines were given six months before the
onset of illness.
Cases Nos. 307, 310, 320 and 321. Vaccination
was more than seven weeks before the symptoms
appeared, so that the vaccine is not implicated
as the etiologic agent. Since the stool and blood
examinations are incomplete, the analyses of
these cases will be reported later.
COMMENT
Of the 59 cases diagnosed as paralytic poliomyelitis
which have occurred in Costa Rica
since the start of the oral vaccination program
on 17 March 1959, 14 occurred among vaccinated
individuals. The onset of symptoms was
at least seven weeks after vaccination in 13 of
the 14. In the 14th case the onset was 10 days
after the administration of the trivalent vaccine.
Laboratory studies of sera and rectal swabs are
as yet incomplete in this case.
The attack rate in the outbreak in the metropolitan
area in 1960 was 128 per 100,000 among
the unvaccinated, and 14 per 100,000 among the
vaccinated individuals.