甲型H1N1流感病毒基因组序列分析及其特性研究

Objective To analyse the genome of influenza A (H1N1) vires so as to elucidate its molecular characteristics and evolution status. Methods DNA sequences of the influenza viruses were collected from NCBI, and compared with the genomes of referenced intluenza viruses. The phylogenetic trees were constructed by the neighbor-joining method, and the pathogenicity, drug susceptibility and vaccine protection were analyzed. Results Phyiogenetic analysis showed that the genes encoding HA, PB2, PBI, PA, NP, and NS protein were most closely related to those influenza A viruses circulating in swine populations in North America. NA and M gene belonged to Eurasia lineages swine influenza vires. The amino acid sequence of the cleavage site between HA1 and HA2 was PARSSR ↓ GLFGAI with the typical characteristics of the low pathogenic influenza virus. Influenza A(H1N1) virus can spread from person-to-person. It is sensitive to oseltamivir and zanamivir but resistant to amantadine and remantadine. The current human seasonal influenzavaccines confered little protection against influenza A/H1N1 because of the great diversity on antigenic domains between A/H1N1 virus and vaccine virus. Conclusions Influenza A(H1N1) virus is a reassortant virus of North America and Eurasia hneages swine influenza virus. It is important to develop a vaccine against the currently circulating virus strain to control the disease spread.     

甲型H1N1流感病毒基因组序列分析及其特性研究

Objective To analyse the genome of influenza A (H1N1) vires so as to elucidate its molecular characteristics and evolution status. Methods DNA sequences of the influenza viruses were collected from NCBI, and compared with the genomes of referenced intluenza viruses. The phylogenetic trees were constructed by the neighbor-joining method, and the pathogenicity, drug susceptibility and vaccine protection were analyzed. Results Phyiogenetic analysis showed that the genes encoding HA, PB2, PBI, PA, NP, and NS protein were most closely related to those influenza A viruses circulating in swine populations in North America. NA and M gene belonged to Eurasia lineages swine influenza vires. The amino acid sequence of the cleavage site between HA1 and HA2 was PARSSR ↓ GLFGAI with the typical characteristics of the low pathogenic influenza virus. Influenza A(H1N1) virus can spread from person-to-person. It is sensitive to oseltamivir and zanamivir but resistant to amantadine and remantadine. The current human seasonal influenzavaccines confered little protection against influenza A/H1N1 because of the great diversity on antigenic domains between A/H1N1 virus and vaccine virus. Conclusions Influenza A(H1N1) virus is a reassortant virus of North America and Eurasia hneages swine influenza virus. It is important to develop a vaccine against the currently circulating virus strain to control the disease spread.     

甲型H1N1流感病毒基因组序列分析及其特性研究

Objective To analyse the genome of influenza A (H1N1) vires so as to elucidate its molecular characteristics and evolution status. Methods DNA sequences of the influenza viruses were collected from NCBI, and compared with the genomes of referenced intluenza viruses. The phylogenetic trees were constructed by the neighbor-joining method, and the pathogenicity, drug susceptibility and vaccine protection were analyzed. Results Phyiogenetic analysis showed that the genes encoding HA, PB2, PBI, PA, NP, and NS protein were most closely related to those influenza A viruses circulating in swine populations in North America. NA and M gene belonged to Eurasia lineages swine influenza vires. The amino acid sequence of the cleavage site between HA1 and HA2 was PARSSR ↓ GLFGAI with the typical characteristics of the low pathogenic influenza virus. Influenza A(H1N1) virus can spread from person-to-person. It is sensitive to oseltamivir and zanamivir but resistant to amantadine and remantadine. The current human seasonal influenzavaccines confered little protection against influenza A/H1N1 because of the great diversity on antigenic domains between A/H1N1 virus and vaccine virus. Conclusions Influenza A(H1N1) virus is a reassortant virus of North America and Eurasia hneages swine influenza virus. It is important to develop a vaccine against the currently circulating virus strain to control the disease spread.     

甲型H1N1流感病毒基因组序列分析及其特性研究

Objective To analyse the genome of influenza A (H1N1) vires so as to elucidate its molecular characteristics and evolution status. Methods DNA sequences of the influenza viruses were collected from NCBI, and compared with the genomes of referenced intluenza viruses. The phylogenetic trees were constructed by the neighbor-joining method, and the pathogenicity, drug susceptibility and vaccine protection were analyzed. Results Phyiogenetic analysis showed that the genes encoding HA, PB2, PBI, PA, NP, and NS protein were most closely related to those influenza A viruses circulating in swine populations in North America. NA and M gene belonged to Eurasia lineages swine influenza vires. The amino acid sequence of the cleavage site between HA1 and HA2 was PARSSR ↓ GLFGAI with the typical characteristics of the low pathogenic influenza virus. Influenza A(H1N1) virus can spread from person-to-person. It is sensitive to oseltamivir and zanamivir but resistant to amantadine and remantadine. The current human seasonal influenzavaccines confered little protection against influenza A/H1N1 because of the great diversity on antigenic domains between A/H1N1 virus and vaccine virus. Conclusions Influenza A(H1N1) virus is a reassortant virus of North America and Eurasia hneages swine influenza virus. It is important to develop a vaccine against the currently circulating virus strain to control the disease spread.     

甲型H1N1流感病毒基因组序列分析及其特性研究

Objective To analyse the genome of influenza A (H1N1) vires so as to elucidate its molecular characteristics and evolution status. Methods DNA sequences of the influenza viruses were collected from NCBI, and compared with the genomes of referenced intluenza viruses. The phylogenetic trees were constructed by the neighbor-joining method, and the pathogenicity, drug susceptibility and vaccine protection were analyzed. Results Phyiogenetic analysis showed that the genes encoding HA, PB2, PBI, PA, NP, and NS protein were most closely related to those influenza A viruses circulating in swine populations in North America. NA and M gene belonged to Eurasia lineages swine influenza vires. The amino acid sequence of the cleavage site between HA1 and HA2 was PARSSR ↓ GLFGAI with the typical characteristics of the low pathogenic influenza virus. Influenza A(H1N1) virus can spread from person-to-person. It is sensitive to oseltamivir and zanamivir but resistant to amantadine and remantadine. The current human seasonal influenzavaccines confered little protection against influenza A/H1N1 because of the great diversity on antigenic domains between A/H1N1 virus and vaccine virus. Conclusions Influenza A(H1N1) virus is a reassortant virus of North America and Eurasia hneages swine influenza virus. It is important to develop a vaccine against the currently circulating virus strain to control the disease spread.     

甲型H1N1流感病毒基因组序列分析及其特性研究

Objective To analyse the genome of influenza A (H1N1) vires so as to elucidate its molecular characteristics and evolution status. Methods DNA sequences of the influenza viruses were collected from NCBI, and compared with the genomes of referenced intluenza viruses. The phylogenetic trees were constructed by the neighbor-joining method, and the pathogenicity, drug susceptibility and vaccine protection were analyzed. Results Phyiogenetic analysis showed that the genes encoding HA, PB2, PBI, PA, NP, and NS protein were most closely related to those influenza A viruses circulating in swine populations in North America. NA and M gene belonged to Eurasia lineages swine influenza vires. The amino acid sequence of the cleavage site between HA1 and HA2 was PARSSR ↓ GLFGAI with the typical characteristics of the low pathogenic influenza virus. Influenza A(H1N1) virus can spread from person-to-person. It is sensitive to oseltamivir and zanamivir but resistant to amantadine and remantadine. The current human seasonal influenzavaccines confered little protection against influenza A/H1N1 because of the great diversity on antigenic domains between A/H1N1 virus and vaccine virus. Conclusions Influenza A(H1N1) virus is a reassortant virus of North America and Eurasia hneages swine influenza virus. It is important to develop a vaccine against the currently circulating virus strain to control the disease spread.     

甲型H1N1流感病毒基因组序列分析及其特性研究

Objective To analyse the genome of influenza A (H1N1) vires so as to elucidate its molecular characteristics and evolution status. Methods DNA sequences of the influenza viruses were collected from NCBI, and compared with the genomes of referenced intluenza viruses. The phylogenetic trees were constructed by the neighbor-joining method, and the pathogenicity, drug susceptibility and vaccine protection were analyzed. Results Phyiogenetic analysis showed that the genes encoding HA, PB2, PBI, PA, NP, and NS protein were most closely related to those influenza A viruses circulating in swine populations in North America. NA and M gene belonged to Eurasia lineages swine influenza vires. The amino acid sequence of the cleavage site between HA1 and HA2 was PARSSR ↓ GLFGAI with the typical characteristics of the low pathogenic influenza virus. Influenza A(H1N1) virus can spread from person-to-person. It is sensitive to oseltamivir and zanamivir but resistant to amantadine and remantadine. The current human seasonal influenzavaccines confered little protection against influenza A/H1N1 because of the great diversity on antigenic domains between A/H1N1 virus and vaccine virus. Conclusions Influenza A(H1N1) virus is a reassortant virus of North America and Eurasia hneages swine influenza virus. It is important to develop a vaccine against the currently circulating virus strain to control the disease spread.     

甲型H1N1流感病毒基因组序列分析及其特性研究

Objective To analyse the genome of influenza A (H1N1) vires so as to elucidate its molecular characteristics and evolution status. Methods DNA sequences of the influenza viruses were collected from NCBI, and compared with the genomes of referenced intluenza viruses. The phylogenetic trees were constructed by the neighbor-joining method, and the pathogenicity, drug susceptibility and vaccine protection were analyzed. Results Phyiogenetic analysis showed that the genes encoding HA, PB2, PBI, PA, NP, and NS protein were most closely related to those influenza A viruses circulating in swine populations in North America. NA and M gene belonged to Eurasia lineages swine influenza vires. The amino acid sequence of the cleavage site between HA1 and HA2 was PARSSR ↓ GLFGAI with the typical characteristics of the low pathogenic influenza virus. Influenza A(H1N1) virus can spread from person-to-person. It is sensitive to oseltamivir and zanamivir but resistant to amantadine and remantadine. The current human seasonal influenzavaccines confered little protection against influenza A/H1N1 because of the great diversity on antigenic domains between A/H1N1 virus and vaccine virus. Conclusions Influenza A(H1N1) virus is a reassortant virus of North America and Eurasia hneages swine influenza virus. It is important to develop a vaccine against the currently circulating virus strain to control the disease spread.     

甲型H1N1流感病毒基因组序列分析及其特性研究

Objective To analyse the genome of influenza A (H1N1) vires so as to elucidate its molecular characteristics and evolution status. Methods DNA sequences of the influenza viruses were collected from NCBI, and compared with the genomes of referenced intluenza viruses. The phylogenetic trees were constructed by the neighbor-joining method, and the pathogenicity, drug susceptibility and vaccine protection were analyzed. Results Phyiogenetic analysis showed that the genes encoding HA, PB2, PBI, PA, NP, and NS protein were most closely related to those influenza A viruses circulating in swine populations in North America. NA and M gene belonged to Eurasia lineages swine influenza vires. The amino acid sequence of the cleavage site between HA1 and HA2 was PARSSR ↓ GLFGAI with the typical characteristics of the low pathogenic influenza virus. Influenza A(H1N1) virus can spread from person-to-person. It is sensitive to oseltamivir and zanamivir but resistant to amantadine and remantadine. The current human seasonal influenzavaccines confered little protection against influenza A/H1N1 because of the great diversity on antigenic domains between A/H1N1 virus and vaccine virus. Conclusions Influenza A(H1N1) virus is a reassortant virus of North America and Eurasia hneages swine influenza virus. It is important to develop a vaccine against the currently circulating virus strain to control the disease spread.     

上海市中小学生接种甲型H1N1流行性感冒疫苗的成本-效益分析

目的 评价上海市中小学生接种甲型H1N1 流行性感冒(简称甲流)病毒裂解疫苗(简称甲流疫苗)的成本效益.方法 采用准试验设计,在上海市6个区县的中小学生中开展甲流疫苗接种和效益评估,共观察414 636名中小学生.按自愿原则,将研究对象分为接种组(233 445名)和对照组(181 191名).采用问卷调查方法在上海市19个区县预防接种机构收集疫苗接种成本信息;通过问卷调查和回顾性病历摘录等方法收集就医成本信息,其中包括31例轻症、15例重症甲流病例.最后采用卫生经济学评估方法进行流行性感冒(简称流感)疫苗的成本-效益分析.结果 共观察414 636名中小学生,其中接种组233 445名,占56.3%,对照组181 191名.疫苗接种后,接种组流感罹患率为0.61%(1433/233 445),对照组罹患率为1.76%(3166/181 191),接种组流感样病例保护率为65.34% [(1.76-0.61)/1.76].人均接种甲流疫苗的成本为36.81元.轻症甲流病例门诊费用为(358.3±243.6)元,甲流重症病例住院费用为(49 188.4±99 917.3)元.中小学生甲流疫苗接种总效益为19 155 566.3元;接种净效益为10 560 673.7元,效益-成本比为2.24:1.结论 上海市中小学生接种甲流疫苗有一定的保护效果,具有较好的效益,是一种值得尝试的干预策略.

Abstract：

s of retrospective medical records,which included 31 mild cases and 15 severe cases.The cost-benefit analysis was conducted by health economic evaluation.Results In total,there were 414 636 students enrolled in this study; while 233 445 (56.3%) students were in the vaccinated group and 181 191 in the control group.The attack rate in vaccinated group and control group was 0.61%(1433/233 445) and 1.76%(3166/181 191) respectively.The protection ratio was 65.34% ((1.76-0.61)/1.76) in the vaccinated group.The average cost of Influenza H1N1 was 36.81 yuan/person; and the average cost of medical treatment was (358.3±243.6) yuan/mild case and (49 188.4±99 917.3) yuan/severe case.The total benefit of vaccination in schools was 19 155 566.3 yuan,and the net 1.Conclusion Influenza H1N1 vaccine could protect the students from Influenza H1N1 infection,and the cost-benefit analysis showed that the intervention strategy was worth trying.     

无锡市甲型H1N1流感及季节性流感疫苗接种效果分析

目的调查流感样病例(ILI)和无锡市一般人群中甲型H1N1流感疫苗及季节性流感疫苗的接种情况,评估疫苗接种后对人群的保护效果。方法以无锡市2家哨点医院为基础,采集流感样病例病毒核酸检测阳性的病例作为病例组,共1 529人,同时按照"病例"的电话信息,随机产生电话号码选择、年龄匹配的一般人群作为对照组,共380人。结果病例组甲型H1N1流感疫苗接种率为6.1%(94/1 529),对照组甲型H1N1流感疫苗接种率为12.1%(46/380),两组比较,差异有统计学意义(P0.01);甲型H1N1流感病例中接种甲型H1N1流感疫苗的比例为12.5%(3/24),门诊检测阴性的ILI病例接种甲型H1N1流感疫苗的比例为6.1%(78/1 273),"接种甲型H1N1流感疫苗"因素的OR值为0.457(P=0.201);以电话调查一般人群(330例)作为对照组,接种甲型H1N1流感疫苗的比例为13.3%(44/330),OR值为1.077(P=0.908)。结论该次调查说明接种甲型H1N1流感疫苗对预防流感样病例有一定效果,但由于样本量较少,24种方法病例对照分析均未得出差异有统计学意义。     

Study of live recombinant cold-adapted influenza bivalent vaccine of type A for use in children: an epidemiological control trial

Live cold-adapted recombinant bivalent vaccine of influenza type A was studied in a controlled field trial in 1982-1983 among nearly 30,000 children 3-15 years old. The bivalent vaccine consisted of recombinants 47/25/1 (H1N1) and 47/7/2 (H3N2) of wild-type viruses A/Brazil/11/78 (H1N1) and A/Bangkok/1/79 (H3N2) with cold-adapted donor A/Leningrad/134/47/57 (H2N2). The recombinants which received mutant nonglycoprotein genes from cold-adapted donor did not suppress each other after simultaneous inoculation of children and stimulated antibody response to both strains. The bivalent vaccine was completely attenuated for children. It caused less than 1% transient febrile reactions during five days after the first vaccination, including double seronegative individuals with low antibody titres to both vaccinal strains. The cold-adapted bivalent vaccine tested proved to be safe for children according to the analysis of morbidity studies among vaccines and a control group performed during the five days and the following six months after the first immunization. There is a similar distribution of non-influenza illnesses and a statistically significant decrease in influenza-like diseases among vaccines compared to the control group. In the four months after the immunization programme was completed, epidemics of influenza A H1N1 and H3N2 occurred. The incidence of influenza-like diseases was approximately 50% less in the vaccinated than in the control groups. This is the first evidence of safety and protective efficacy of recombinant live influenza vaccine for children 3-15 years of age.     

2009年上海市中小学生甲型H1N1流感疫苗大规模接种流行病学效果评价

目的 评价2009年上海市中小学生接种甲型H1N1流行性感冒疫苗(简称甲流疫苗)的流行病学效果.方法 研究对象为长宁、杨浦、闸北、普陀、浦东新区和崇明县内接受甲流疫苗接种(接种组)和未接受甲流疫苗接种(对照组)的在校中小学生,分别收集接种组与对照组学生每日的发热和流感样病例数,通过计算疫苗保护率和保护效果指数,以评价甲流疫苗的流行病学效果.结果 甲流疫苗接种前,流感样病例的发病高峰是在2009年11月,流感样病例罹患率达6.19%.接种疫苗后,接种组发热的罹患率为0.98%,流感样病例的罹患率为0.61%;对照组发热的罹患率为2.37%,流感样病例的罹患率为1.75%.与对照组相比,接种组甲流疫苗接种后控制发热的保护率为58.65%,保护效果指数为2.42,控制流感样病例的保护率为65.14%,保护效果指数为2.87.结论 接种甲流疫苗可以降低中小学生发热及流感样病例的发生率,具有一定的保护作用.     

Genetic sequence analysis of influenza viruses and illness severity in ill children previously vaccinated with live attenuated or inactivated influenza vaccine

In a large comparative study in 2004–2005, children aged 6–59 months vaccinated with live attenuated influenza vaccine (LAIV) experienced 55% fewer cases of culture-confirmed influenza illness compared with trivalent inactivated influenza vaccine (TIV) recipients. To better understand the characteristics of the breakthrough influenza illnesses, we analyzed the HA1 genetic sequence for all available samples and examined disease severity by strain and treatment group. All 48 A/H1N1 viruses were well-matched to the vaccine, whereas all 276 A/H3N2 viruses and 349 (96%) influenza B viruses were mismatched to the vaccine. The incidence of fever or lower respiratory illness did not differ by strain; however, LAIV recipients had less febrile disease and fewer lower respiratory illnesses than TIV recipients. Viruses of each influenza B lineage caused more illnesses than A/H1N1 viruses; strategies to enhance protection against multiple influenza B lineages should be pursued.     

甲型H1N1流感疫苗免疫效果及影响因素研究

目的了解学生大规模接种甲型H1N1流感疫苗的免疫效果及影响因素,为探索甲型H1N1流感免疫策略和防控措施提供科学依据。方法分别对344名中学生在甲型H1N1流感疫苗接种前及接种后1个月采集血清标本,进行抗体水平的检测。并收集中学生在接种疫苗前季节性流感疫苗接种史、流感样症状等有关流行病学信息,评价甲型H1N1流感疫苗的免疫效果及影响因素。结果 344名中学生在免前H1N1流感抗体几何平均滴度(GMT)为1∶16.97(95%CI:1∶14.49~1∶19.86),抗体阳性率为36.50%(95%CI:31.35%~41.89%);免后GMT为1∶167.41(95%CI:1∶145.08~1∶193.18),阳性率为89.91%(95%CI:86.19%~92.91%),阳转率为72.54%(95%CI:67.76%~77.32%),均明显高于免前。接种疫苗前3个月的季节性流感疫苗接种史、流感样症状史等因素分组后,各组间免疫学效果指标间差异无统计学意义(P>0.05)。结论接种甲型H1N1流感疫苗后免疫成功率70%以上,符合欧盟和美国FDA的有关规定,免疫效果良好。季节性流感疫苗接种史、流感症状史等对疫苗的免疫学保护效果无明显影响。     

Effectiveness of the monovalent AS03-adjuvanted influenza A(H1N1)pdm09 vaccine against hospitalization in children because of influenza

We studied the effectiveness of the AS03-adjuvanted monovalent vaccine (Pandemrix^®) for the prevention of severe pandemic influenza A(H1N1)pdm09 in children, in 2009. All children hospitalized for influenza-like illness in Stockholm County during the peak of the pandemic were included. We compared the frequency of vaccinated children between influenza A(H1N1)pdm09 PCR positive cases and PCR negative controls in a retrospective case–control study.     

The effectiveness of influenza vaccination among nursery school children in China during the 2016/17 influenza season

BackgroundThe effectiveness of influenza vaccine among nursery school children has not been systematically studied. We conducted a cohort study of children from 13 nursery schools in Suzhou, China, to estimate the effectiveness of influenza vaccine against laboratory-confirmed influenza during 2016–17.MethodsChildren aged 36–72 months were chosen from 13 nursery schools from 3 District in Suzhou. The surveillance started 2 weeks after vaccination during October 2016–February 2017. Class teachers reported the names of students with ILI (influenza-like illness) to study clinicians on each school day. Further, local physicians collected the student’s nasopharyngeal swab or throat swab, either at a study clinic or at the child’s home. The swabs were sent to the National Influenza Network Laboratory in Suzhou Center for Disease Control and Prevention for influenza testing by RT-PCR.ResultA total of 4614 children were enrolled, of which 15 children (vaccinated: 2; unvaccinated: 13) were lost to follow-up. Of the remaining 4599 children, 558 swabs were collected. Among these swabs, 70 samples tested positive for influenza virus; 17 in the vaccinated group (B Victoria: 2; H3N2: 15) and 53 in the unvaccinated group (B Victoria: 14; A(H1N1)pdm09: 1; H3N2: 38). The overall influenza vaccine effectiveness (VE) during the influenza season of 2016–2017 was 20.6%. The incidence of developing ILI symptoms and healthcare seeking behavior through clinical visits was significantly lower in vaccinated children than in the unvaccinated group.ConclusionInfluenza vaccine protection in vaccinated and unvaccinated children showed no statistical difference and the VE percentage varied for different virus subtypes. However, the incidence rate of developing ILI and healthcare seeking behavior was significant lower in the vaccinated group than in the unvaccinated children. Larger studies are required to estimate the VE according to the influenza type, subtype, and lineage during influenza seasons in China in the future.     

甲型H1N1流感大流行前后沈阳地区流感病原学流行特征

目的分析甲型H1N1流行性感冒(流感)大流行前后沈阳流感病原学流行特征。方法采集2005年10月—2011年3月连续5.5 a哨点医院的流感样病例咽拭子,进行流感病毒的分离和分型鉴定,并按甲型H1N1流感流行前后划分为3个时期。结果 3个时期共采集流感样病例咽拭子样本6 808份,分离到流感病毒861株,总分离率为12.6%;流行前、流行中和流行后3个时期流感病毒检出率分别为13.8%、18.2%和5.2%。男性和女性流感病毒感染率差异无统计学意义,不同时期流感样病例的年龄构成差异有统计学意义。新的甲型H1N1流感侵袭的人群主要是低年龄组人群,新的甲型H1N1流行期间和流行后,流感季节高峰发生前移。不同年度流感流行毒株型别不同,前1年监测周期的优势株在下1个周期中可被其他型别抑制甚至取代。结论甲型H1N1流感流行后沈阳的流感流行特征已发生了部分改变,这种改变是否持续存在还有待持续监测来得以验证,在2011—2012年监测周期中应密切关注A3(H3N2)亚型和新的甲型H1N1亚型流感毒株的活动情况。     

湘西自治州甲型H1N1流感血清流行病学调查

目的 了解湘西自治州人群甲型H1N1流感病毒感染状况和免疫水平,分析流感流行趋势,为制定针对性的防治措施提供依据.方法 采用多阶段分层随机抽样方法,于2010年1月4月8月共选取675人进行问卷调查,并采集血液标本进行甲型H1N1流感病毒血凝抗体检测.结果 在不同季节,不同职业人群中H1抗体阳性率不同(P＜0.05),同时在出现过急性呼吸道症以及接种过甲型H1N1流感疫苗的人群中H1抗体阳性率相对较高(P＜0.05).H1抗体GMT呈现季节性变化(P＜0.05),在不同年龄,不同职业人群中抗体水平大小差异有统计学意义(P＜ 0.05,P＜ 0.01).调查还发现发现出现过急性呼吸道症人群中抗体GMT和中位数高于未出现呼吸道症状者(P＜ 0.001);接种过甲型H1N1流感疫苗者抗体GMT和中位数也同样高于未接种者(P＜ 0.001).在不同性别和民族人群中,抗体的阳性率和水平大小无统计学差异.结论 目前湘西地区甲型H1N1流感已经得到有效控制,但鉴于人群中保护性抗体水平季节性变化,下一阶段重点是定期开展快速的血清学监测,并且继续对高危人群实施甲型H1N1流感疫苗接种.