Antigenic and genetic study of influenza virus (H1N1) circulated in China in 2004-2005 / 中华实验和临床病毒学杂志

ABSTRACT

<p><b>BACKGROUND</b>To analyze the genetic and antigenic characteristics of hemagglutinin (HA) gene of human influenza (H1N1) virus isolated from the mainland of China since 2004 to 2005.</p><p><b>METHODS</b>The single-way hemagglutination inhibition (HI) tests were used to test the antigenic characteristics, and the HA1 gene was sequenced based on the antigenic results.</p><p><b>RESULTS</b>The single-way HI results showed that no virus isolates had 4-folds greater HI titer compared with A/Shanghai/1/1999 (H1N1) in 2004, but there was 6.3% virus had 4-fold greater difference in 2005. The HA1 sequence data showed that the H1N1 virus had the following amino acid mutations such as 54 K > R, 90 T > K, 101 Y > H, 149 R > K, 169 V > A, 190 D > N, 212 R > K, 219 K > R, 245 W > R, 246 Y > F, 258 T > N, 318 V > A and the 54 and 190 amino acids located in antigenic group of HA1.</p><p><b>CONCLUSION</b>The H1N1 virus was changing in antigenic and genetic characteristics.</p>