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Updated: Jul 1, 2026

An Optimized Hemagglutination Inhibition (HI) Assay to Quantify Influenza-specific Antibody Titers
Published on: December 1, 2017
Antibody to Haemophilus influenzae type b after routine and catch-up vaccination
C L Trotter1, J McVernon, N J Andrews
1Immunisation Division, Communicable Disease Surveillance Centre, Health Protection Agency, 61 Colindale Avenue, NW9 5EQ, London, UK. caroline.trotter@hpa.org.uk <caroline.trotter@hpa.org.uk>
Abstract:
Since 1999, the number of cases of Haemophilus influenzae type b (Hib) disease in the UK has risen. We investigated the role of population immunity in this change by testing more than 2600 serum samples from children aged 1-15 years. After the introduction of the routine Hib conjugate vaccination programme for infants, median antibody titres rose significantly in 1-year-olds. Individuals who received their first dose of vaccine at age 1-4 years in the original catch-up campaign initially had much higher concentrations of antibody than those who had been immunised in infancy. A second catch-up campaign in children aged 6 months to 4 years should be highly effective in boosting immunity and reducing disease in the short term.
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