[Use of the passive hemaglutination reactions for the determination of anti-smallpox antibodies in primary vaccination and revaccination against smallpox].

The authors present the results of studying the PHAT sensitivity in comparison with the neutralization test and the hemagglutination inhibition test in examination of 254 sera of revaccinated and 95 sera of primarily vaccinated children. It appeared that PHAT was characterized by a sufficiently high sensitivity, and reproducibility, in case the same batch of erythrocytic diagnostic agent was used; at the same time the test was simple, accessible, economic, and gave rapid results. This test can be used for assessment of the immunological efficacy of smallpox revaccination.