Prostacyclin in pregnancy.

Abstract

Antibody persistence in stored sera-On testing in 1978 the geometric mean titre of haemagglutination inhibition antibody in the 16 sera collected 46 days after vaccination and still available for retitration was 64 4, compared with 128-8 originally; five samples (31 °O) showed a fourfold fall in titre (table ).This was probably due to loss of antibody during storage and not to the different methods of removing norn-specific inhibitors (acid-washed kaolin in 1968, manganous chloride and heparin in 1978).Antibody persistence after vaccination-All sera had detectable haem- agglutination antibody 10 years after vaccination (table).Antibody titres had fallen fourfold in four (20 (O) subjects (three of the 12 not revaccinated and one of the eight revaccinated) and had increased fourfold in one of the revaccinated subjects.Neutralising antibody was present in all 12 subjects not revaccinated, at titres of 1 in 32 (three subjects), 1 in 8 (five), and 1 in 4 (four).Titres of haemtagglutintation inhibition anztibody in sera collected 46 days after vaccination int 1968 (tested in 1968 and 1978) and 10 years after vaccination.(Suibjects in cases 13-20 zwere revaccinated between 1970 and 1978) Sera obtained 46 days after vaccination* Case 1978 sera* No 1968 1978*Titrated in parallel.In four cases sera obtained in 1968 were no longer available, so tsera obtained in 1970 and +sera obtained in 1974 were substituted.