亚洲甲型流感病毒发源的研究 Ⅱ.亚洲甲型（A2）与亚甲型（A1）流感病毒的抗原关系

STUDIES ON THE ORIGIN OF A2 INFLUENZA VIRUS Ⅱ.ANTIGENIC RELATIONSHIP BETWEEN A1 AND A2 INFLUENZA VIRUS

最近几年,许多学者对于A2流感病毒的发源曾进行过研究,并提出一些假设,这些假设有的单凭少数病毒株的抗原关系,有的尚缺乏直接的有力的证据,故仍未能令人满意地解释A2流感病毒的发源问题。 1957年A2型流感的大流行首先在我国发生,早在1957年2月在我国贵州省已有流行,同时分离出A2病毒。其后,在3、4月份全国各地均先后发生,所有分离的病毒经鉴定均属A2型。在A2流行之前。

In order to detect the serological relationship between A2 and other influenza Aviruses, haemagglutination-inhibition and neutralization tests were performed on serveralA2 and A1 strains isolated in the last few years. Representative strains of swine and Aviruses were also included. Sera from hyperimmunized roosters were used. The results of cross haemagglutination-inhibition and neutralization tests showedthat the earlier influenza A1 virus （FM1, Peking 56-1） did not cross react with the A2virus. However, A1 strain such as Loying 57-3 and Loyang 57-4 （belonging to theD/56 group） did show clear cross reaction with the A2 virus. This fact indicates that theantigenic patterns of these two strains are intermediate between A2 and earlier A1 viruses. Further analysis of A1 influenza viruses, isolated in China form 1953--1957,showed that the intermediate strains first appeared in Shanghai and Shenyang in July1956. Moreover, according to reports in the literature, the first strain of this groupwas isolated in February--March 1956 in Holland. From the results mentioned above, especially from the antigenic relationship of theintermediate strains with both A2 and earlier A1 influenza virus, it is suggested that theA2 influenza virus originated from A1. Other epidemiological and virological evidencesin support of this conclusion were also presented.