bly has an adequate sensitivity because ithas detected frequencies of antibody ... of HA inhibition tests and to Judy Galphin and Carol Stocks- dale for excellent ...
Vol. 29, No. 3
INFECTION AND IMMUNITY, Sept. 1980, p. 966-971
0019-9567/80/09-0966/06$02.00/0
Further Studies of the Neuraminidase Content of Inactivated Influenza Vaccines and the Neuraminidase Antibody Responses After Vaccination of Immunologically Primed and Unprimed Populations ALAN P. KENDAL,'* F. MARILYN BOZEMAN,2 AND FRANCIS A. ENNIS2 World Health Organization Collaborating Center for Influenza, Virology Division, Center for Disease Control, Atlanta, Georgia 30333,1 and Virology Division, Bureau of Biologics, Bethesda, Maryland 202052
Purified concentrates of influenza A/USSR/90/77(H1N1)-like, A/Texas/1/77 (H3N2)-like, and B/Hong Kong/5/72-like viruses used for preparation of investigational and licensed vaccines in 1978 to 1979 were tested for their content of neuraminidase enzyme activity. Concentrates of H1N1 virus used to prepare vaccines for clinical investigations performed in the spring of 1978 had neuraminidase activity at that time which decreased during storage to almost undetectable levels (three lots) or by 50% (one lot) by the winter of 1978. Several other lots of concentrates prepared with H1N1 virus and used for vaccine formulation had no detectable neuraminidase enzyme activity when tested in the winter of 1978, at a time when they would be administered in vaccines. The range of specific activity for different lots of concentrates was about 40-fold for A/Texas/1/77, B/Hong Kong/5/72, and A/USSR/90/77 neuraminidases. Immunogenicity of investigational vaccines prepared with tested concentrates and administered between April and July 1978 was measured in volunteers aged 13 to >50 years. Frequency of neuraminidase antibody rises to two doses of HlNl-containing vaccine was 10% in unprimed subjects aged 50 21 N1 (0.9) 2-WV H1 (12,17) 4.9 12 27 41 22 137 86 22 >50 N1 (1.36) H1 (10,15) 3-SV 3.6 2.5 ND 12 41 10 62 34 N2 (5.6) 13-25 2-WV H3 (23) 6.4 3.5 ND 32 14 206 91 34 13-25 N2 (14.4) H3 (23) 3-SV 3.6 2.7 ND 15 39 11 55 33 26-50 N2 (5.6) 2-WV H3 (23) 3.2 2.2 ND 18 14 120 22 ND 77 26-50 N2 (14.4) H3 (23) 3-SV 3.3 3.7 0 44 ND 28 21 ND 29 >50 N2 (5.6) 2-WV H3 (23) 4.2 4.2 ND 27 22 100 22 ND 59 >50 N2 (14.4) H3 (23) 3-SV 4.0 3.0 ND 18 74 14 ND 64 166 Sub-total for H3N2, all ages a Units of HA are ,ug of protein (doses 1 and 2). Units of NA are calculated assuming that each vaccine dose contains 20 ,ug of HA, the nominal concentration. ' Rise in anti-HA antibody titer of from 20, or fourfold, when measured with whole virus A/USSR/ 90/77 and/or ether-treated virus A/USSR/92/77 (for HiN1 vaccine); and with A/Texas/1/77 virus (for H3N2 vaccine). Rise in anti-NA antibody titer of from 5, or threefold, when measured with whole virus A/ USSR/92/77 (for HiNi vaccine); and with A/equine/Prague/56 (Heql)-Texas/1/77(N2) (for H3N2 vaccine). SI, Prevaccination serum; S2, serum collected 4 weeks after first vaccination; S3, serum collected 2 weeks after second vaccination; ND, not determined. See text for description of vaccination schedule. 'Geometric mean titer (GMT) calculated assuming a value of 5 for anti-HA titers
