Gill P W, Murphy A M, Cunningham A L
Department of Virology, Institute of Clinical Pathology and Medical Research, Westmead Hospital, NSW.
Med J Aust. 1991 Sep 16;155(6):362-7. doi: 10.5694/j.1326-5377.1991.tb101308.x.
To study the incidence of H1N1 influenza from 1977 to 1988 in unvaccinated volunteers and the effects of continuing minor antigenic change (antigenic drift) in the virus.
Prospective study by a group of general practitioners, backed up by virological findings.
Mainly patients of the general practitioner group, also some doctors and members of staff. There were 287 participants during 1977-1981, and 207 at the end of 1988.
Any participant deemed to be "at risk" was encouraged to be vaccinated and to withdraw from the study.
In 1957, H1N1 subtype influenza had been displaced by H2N2 (Asian) subtype. In 1968, H2N2 was displaced by H3N2 (Hong Kong) subtype. During 1977, H1N1 influenza unexpectedly reappeared in Asia, and spread widely. The resurgent strain, designated A/USSR/90/77(H1N1), caused world pandemics, attacking (almost exclusively) persons who had been born since the 1950-1951 northern winter and causing negligible mortality. It did not displace the current H3N2 strain, and strains of both subtypes have continued to emerge independently.
Antigens of A/USSR resembled closely those of the 1950-1951 H1N1 strain, which apparently was rendered antigenically inert between 1951 and 1976 (possibly frozen) and was reactivated during 1977. Antigenic drift was then resumed.
The A/USSR/90/77 strain and its close successor, A/Brazil/11/78, attacked mainly the young, whose previous exposure to H1N1 antigens had been minimal or zero. Mortality during the A/USSR pandemics was negligible because death from influenza in people aged less than 30 years is rare. Would continuing antigenic drift ultimately widen the H1N1 spectrum of attack?
During the epidemic of 1988, A/Taiwan/1/86(H1N1) attacked a wider range of age groups than had A/USSR or A/Brazil.
Assuming that H1N1 viruses continue to undergo further antigenic drift, an ever widening age spectrum of H1N1 attack may be expected.
研究1977年至1988年未接种疫苗的志愿者中H1N1流感的发病率以及病毒持续发生的微小抗原变化（抗原漂移）的影响。
由一组全科医生进行的前瞻性研究，并得到病毒学研究结果的支持。
主要是全科医生组的患者，也有一些医生和工作人员。1977 - 1981年期间有287名参与者，1988年底有207名。
任何被认为“有风险”的参与者都被鼓励接种疫苗并退出研究。
1957年，H1N1亚型流感被H2N2（亚洲）亚型取代。1968年，H2N2被H3N2（香港）亚型取代。1977年，H1N1流感意外地在亚洲重新出现并广泛传播。这种复苏的毒株，被指定为A/USSR/90/77(H1N1)，引发了全球大流行，主要侵袭（几乎完全是）自1950 - 1951年北半球冬季以来出生的人，死亡率极低。它没有取代当时的H3N2毒株，两种亚型的毒株继续独立出现。
A/USSR的抗原与1950 - 1951年H1N1毒株的抗原非常相似，该毒株在1951年至1976年期间显然变得抗原性无活性（可能处于“冻结”状态），并在1977年重新激活。然后恢复了抗原漂移。
A/USSR/90/77毒株及其紧密后续毒株A/Brazil/11/78主要侵袭年轻人，他们之前对H1N1抗原的接触极少或为零。A/USSR大流行期间的死亡率可忽略不计，因为30岁以下人群因流感死亡的情况很少见。持续的抗原漂移最终会扩大H1N1的攻击范围吗？
在1988年的疫情中，A/Taiwan/1/86(H1N1)侵袭的年龄组范围比A/USSR或A/Brazil更广。
假设H1N1病毒继续发生进一步的抗原漂移，预计H1N1的攻击年龄范围会不断扩大。
