中国疫苗和免疫最新文献

DNA vaccine is one of the most attractive project in the research of vaccine now. DNA tumor vaccines mainly include tumor-associated-antigens-based completed, epitope, idiotope determinants DNA vaccine, fusion DNA vaccines, RNA self-replicating vaccines, dendritic cell-based tumor vaccines etc. The recent developments are discussed in the article.

Hepatitis B virus (HBV) is one of the most dangerous risk factors of hepatocellular carcinoma (HCC). How HBV infection leads to the occurrence and development of HCC is complicated. It is not only related with physical condition of HBV infection host, environment, HBV genotype, HBV viral load and gene mutation, but also related with age of HBV infection host, types of infection, and host chromosome integration site.

Objective: Analysis of epidemiology of 4 clustered high risk acute flaccid paralysis(AFP) cases reported by Shanxi province in 2006 and VP1 gene characteristic for type III poliovirus isolated from the four AFP cases.

Methods: Virus isolation and identification were conducted according to the 4th edition of WHO polio laboratory manual. The sequence of VP1 region were amplified and sequenced. The phylogenetic trees based on VP1 region were constructed.

Result: Three of four high risk AFP cases were suspected as vaccine associated paralysis poliomyelitis (VAPP), the onset date of them were close. VP1 sequencing of the four type III isolates revealed that the identity were 99.7%, 99.9%, 99.4% and 99.9% respectively compared with vaccine reference strain-BJOPV3. According to WHO criteria, the four isolates were identified as type III vaccine-related poliovirus. Phylogenetic analysis based on VP1 coding sequence showed that the four type III poliovirus were not related significantly. The type III poliovirus isolated from 3 suspected VAPP cases shared one nucleotide mutation at 2637 (C-->U), which result in the amino acid mutation from Val into Ala.

Conclusion: The improvement of laboratory surveillance for clustered high risk AFP cases should be strengthened so as to detect and prevent poliovirus circulation timely.

Objective: To understand the level of measles antibody in productive women in Hongkou district in Shanghai, to provide evidence for immunization strategy.

Methods: Using quantitative enzyme-linked immunosorbent assay (ELISA) method to test the level of measles antibody IgG.

Results: Positive rate of measles antibody in productive women in Shanghai was 88.68%. The measles antibody's geometric mean concentration (GMC) was 814.73 IU/ml. Positive rate of measles antibody in floating productive women was 91.81%, and GMC was 1376.24 IU/ml. The positive rate of measles antibody decreased with age.

Conclusion: The productive women should be vaccinated against measles vaccine before pregnancy so as to improve the antibody level.

Objective: To evaluate the epidemiological effect of Haemophilus influenzae type b conjugate vaccine (Hib).

Methods: Prospective Cohort Study was conducted to detect carrier rate of Hi in unvaccinated and vaccinated children by bacteria culture and Nest-PCR. Carrier rate of Hi and the incidence of lower respiratory tract infection in two groups children were analysed.

Results: The carrier rate of Hib in two groups children was very lower. The positive rate of NTHi in unvaccinated children was higher than vaccinated children significantly, which was mainly happened in the Children of 2-3 years old. The incidence of lower respiratory tract infection in unvaccinated children was higher than vaccinated children obviously. The protective effect of Hib vaccine against bronchitis was over 90%. The incidence of bronchitis of Hi culture positive was higher than that of Hi culture negative significantly.

Conclusion: Children's bronchitis is related to the Hi carrier rate. To inoculate Hib vaccine can reduce the carrier rate of Hi and the incidence of bronchitis.

Objective: To analysis the running status of measles laboratory network (MLN), and to provide the experience for measles surveillance.

Methods: The results of the confirmation data for measles specimen were analysed in 2008.

Result: 4597 suspected measles cases were reported from MLN in Gansu in 2008, and 3762 sera samples were collected. The collection rate was 81.8%, 1879 of them were IgM positive for measles, and the positive rate was 49.9%. 1343 rubella sera specimen were detected, 611 of them were IgM positive for rubella, and the positive rate was 45.5%. According to the dentification from Chinese CDC, H1a genotype was only type of 3 measles strains found in Gansu by RT-PCR and nucleotide sequencing analysis.

Conclusion: The laboratory network were running well in 2008.

Objectives: To investigate the phylogenetic relationship between swine influenza A/H3N2 virus and the representative strains of human influenza A/H3N2 virus isolated in two epidemics in recent years through comparing the sequences within HA and NA genes.

Methods: HA and NA gene of the human representative strains were sequenced, and then phylogenetic tree with the swine and human strains isolated in the corresponding period of time were constructed.

Results: The homologies on the HA1 domain between human representative strains (A/Zhejiang/10/98, A/Zhejiang/6/99 and A/Zhejiang/8/02)and the swine strains (A/SW/Ontario/130/97, A/SW/Hongkong/4361/99 and A/SW/Hongkong/74/02) were 99.1%, 99.4% and 99.4% respectively. Based on the NA gene, the homologies between human strains (A/Zhejiang/10/98, _A/Zhejiang/6/99 and A/Zhejiang/8/02)and the swine strains (A/SW/Ontario/130/97, A/SW/Hongkong/4361/99 and A/SW/Hongkong/74/02) were 98.2%, 99.3% and 99.3% respectively. The results showed that the two types of influenza viruses were highly homologue, and even some of their homologies were higher than that amongst the contemporary human influenza A/H3N2 strains. The same results shown in the phylogenetic tree.

Conclusions: The human influenza A/H3N2 virus isolates in the two epidemic closely associated with some of the swine influenza virus strains, and their relationship should be further studied.

Objective: To study the molecular characteristics of type 1 poliovirus isolated from the acute flaccid paralysis (AFP)surveillance system in China in 2009, to provide a scientific basis for maintaining polio-free status for China.

Method: Polymerase chain reaction (RT-PCR) method was used to amplify the VP1 code region of all the type I poliovirus, and the VP1 coding region of the isolated stains was sequenced and analyzed, the hot-spots and nuerovirulence determinant were analyzed. The phylogenetic tree was constructed based on VP1 region to analyze the evolutionary relationship between the strains.

Result: The results of VP1 sequencing showed that no wild strains or vaccine-derived poliovirus (VDPVs) were detected. However, five pre-VDPVs were found. And nucleotide sequences of two isolates were in high degree of similarity (100%). Sequence alignment showed that two nucleotides in the VP1 region. nt2747 and nt2749 were two mutation hot spots.

Conclusion: According to the epidemiological and laboratory test results of two high variation strains, the short-term circulation may occur probably, and further research are needed. Meanwhile, the existence of mutation hot spots indicated that strains are easy to reverse into wild-type substitutions, and lead to a series changes of neurological and other virulence when the strains are under selective pressure.

Objective: Application of Real Time Fluorescent quantitative reverse transcription polymerase chani reaction (rRT-PCR)to poliovirus identification in Chinese Poliomyelitis Laboratory Network and evaluation of the assay.

Methods: According to Real-time RT-PCR recommended by WHO and developed by USA Centers for Disease Control and Prevention, 10 poliovirus isolates from laboratories of Chinese poliomyelitis network were tested for intratypic differentiation (ITD) and vaccine derived polioviruses (VDPVs) screening. The results of Real-time RT-PCR for 10 isolates were compared with those of VP, region sequencing.

Result: The Real-time RT-PCR results for 10 isolates did not completely consist with those of VP1 region sequencing. 5 Pre-VDPVs can not be identified by Real-time RT-PCR and type IVDPV from Shanxi province in 2009 was missed by the assay.

Conclusion: The Real-time RT-PCR retrospective and prospective researches for large scale of polioviruses well be conducted to determine if the assay is applicable to Chinese Poliomyelitis Laboratory Network.

Objective: To observe the serum antibody response of the population, whose hepatitis B virus surface antigen(HBsAg), antibody to hepatitis B virus surface antigen (Anti-HBs), antibody to hepatitis B virus core antigen (Anti-HBc) are all negative to the different doses of Hepatitis B vaccine made by recombinant DNA techniques in Yeast and Hansenula Polymorpha Yeast.

Methods: Collecting the blood of population vaccinated after 28 to 45 days, the serological method was used to detect Anti-HBs.

Results: The Anti-HBs positive rate and GMC of 5 microg HepB-Y in the population <16 years old whose HBsAg, Anti-HBs, Anti-HBc negative are 97.23% and 199.26 mlU/ml, the Anti-HBs positive rate and GMC of 10 microg HepB-HPY are 100.00% and 270.71 mlU/ml, the Anti-HBs positive rate and GMC both have significant difference. The Anti-HBs positive rate and GMC of 10 microg HepB-Y in the population > or =16 years old whose HBsAg, Anti-HBs, Anti-HBc negative are 88.72% and 101.19 mlU/ml. Anti-HBs positive rate and GMC of 10 microg HepB-HPY are 94.20% and 162.17 mlU/ml, the Anti-HBs positive rate and GMC both have significant difference.

Conclusions: The population whose HBsAg, Anti-HBs, Anti-HBc negative vaccinated by HepB-Y, HepB-HPY can get better Anti-HBs response. The population younger than sixteen years old vaccinated by 10 microg HepB-HPY can get Anti-HBs positive rate and GMC higher than vaccinated by 5 microg HepB-Y. The Anti-HBs response of HepB-HPY is better than HepB-Y in the population > or =16 years old.