فهرست مطالب mohammad kazem shahkarami

The end of 2019 has marked the year, which the human population encountered a novel virus; SARS-CoV-2 that causes a disease namely COVID-19. Here we focused on the genome and protein mutations and subsequently suggested a new classification of the SARS-CoV-2.

Our study showed that some extra positions in the virus genome play a key role in the SARS-CoV-2 classification. Based on the analysis of the whole genome sequences of 93 viruses.

mutations were classified into nine divisions including IA-1, IA-2, IA-3, IB, II, L1, L2, L3 and S. Totally, 279 mutations were found in the SARS-CoV-2 genomes. 24 mutations lead to the amino acid frame shifting, of which 15 mutations lead to positive frame shifting in amino acids sequences.

Sequence alignment of these positions with that of ancestors showed no change suggesting that they might have occurred in the SARS-CoV-2 genomes to adapt itself to humans.

For more than half a century, the production of fowl pox vaccine at Razi Vaccine and Serum Research Institute, has been carried out by injection method in the chick chorioallantoic membrane (CAM) and the vaccine has a favorable and effective in poultry flocks and has provided a complete satisfaction to the poultry flocks owner. Fowl pox vaccine is also manufactured using chicken embryo cell (CEF) culture in other countries. The aim of this project is to develop fowl pox vaccine based on CEF which is of vital importance and a requirement for Razi institute.

In this study, chicken fibroblastic cells were used as primary cell culture in Hanks or DMEM media supplemented with fetal bovine serum 10% (FBS). First the cells were cultured and the cell count was determined. Subsequently, the virus was added to the cells. The virus that used to prepare the vaccine was initially grew up in the fibroblast cells and had a titer of 106.3 TCID50/ml. To determine the viral load, two methods plaque-forming unit (PFU) and TCID50 were used, safety and efficacy tests were performed on 10 chickens, and the potency test on 20 chickens, and vaccinated chickens were challenged with wild fowl pox virus strain.

The results of the tests showed that the vaccinated chickens had an adequate and sufficient resistance to the acute form of fowl pox virus.

In total, according to the OIE standard, the above experiments showed that cell culture-based fowl pox vaccine can generate good immunity response and have high efficacy.

Fowl pox vaccine is produced in the Razi Institute for almost half a century and has a favorable and productive yield in poultry flocks and has provided complete satisfaction to the poultry breeder. In terms of comparing the efficacy of this vaccine with imported vaccines, the following research was conducted.

In this study, based on the latest protocols of European Pharmacopeia and OIE, 100 SPF chicks were divided into five groups: the first group was given 20 SPF chickens at the age of 8 to 10 weeks of domestic vaccine (Razi Institute: Live attenuated (inoculation in the wing with the needle of the twin branches); also in the second to fourth group: to 60 SPF chicks (in three groups of 20) at the age of 8 to 10 weeks; imported vaccines (I, C and H) were injected. Finally, in the fifth group, 20 chicks were considered as controls and did not receive vaccine. Response of the immune system was observed 7 to 10 days after vaccination by observing nodules at the injection site (Takes reaction). At 21 days (three weeks), all four groups vaccinated with acute pathogenesis of fowl pox strain were challenged.  Chickens were observed daily for 21 days after vaccination and the results of vaccination immunization were evaluated and analyzed by statistical analysis.

The results of the experiments indicated that after vaccination, 100% of the vaccinated chickens were positive by takes responses and after being challenged in four groups vaccinated in the Razi, I, C vaccines 100% and vaccine H, 95% of the immune responses were observed lesions in the Crown of the birds, and in the control group, there were symptoms of cartilage like in 100% of the birds.

In general, according to the OIE standard, the above experiments showed that fowl pox vaccine Razi Institute induces high immunity and has efficacy similar to imported vaccines.

Chemical stabilizers are added to live attenuated vaccines for enhancing the virus stability. The aim of this study was to evaluate the effect of various stabilizers on preserving immunogenicity of lyophilized mumps vaccines.
Study design: An experimental study.
Three mumps vaccines with different formulations were inoculated to three groups of Guinea pigs. Sterile water was injected to eight Guinea pigs as a control group. Blood samples were collected before inoculation and on 14, 28 and 42 d after vaccine injection. Mumps antibodies in the sera were measured using hemagglutination inhibition assay (HAI).
All three formulated mumps vaccines induced antibody in Guinea pigs after two weeks. Formulation 1 containing trehalose dihydrate and formulation 2 comprised human serum albumin stimulated antibodies in the higher level than Razi routine formulation.
Various stabilizers have different preservation potencies that differently affect immune response against virus. More stable and more immunogenic vaccines can be produced using stabilizers containing trehalose dihydrate.

Wild-type RS-12 strain of mumps virus has been isolated from an Iranian patient and has been attenuated after several serial passages. This study was designed to determine nucleotide and amino acid substitutions in the HN, F and SH genes during attenuation of the wild-type virus.
Required viral samples prepared at Razi Vaccine and Serum Institute. Viral RNA was extracted, targeted segments were amplified and sequenced and finally were analyzed using DNAMAN software.
No difference in nucleotide and deduced amino acid sequence of the F and SH genes was detected following attenuation of wild-type as compared to the vaccine strain, but four nucleotide changes in HN gene had occurred which had resulted in two nucleotide differences.
Considering the HN nucleotide sequences and the deduced amino acid sequences, RS-12 wild-type and vaccine strains were distinguishable. Moreover, unique differences between RS-12 and some other vaccine strains existed. During serial passages of RS-12 strain for seed lot system preparation, no change in HN, F and SH genes occurred which -at least in some extents- proved the genetic stability of the attenuated RS-12 surface proteins. Potential attenuating mutations in other genes (N, P, M, L and even non-coding regions in 3′ and 5′ ends) should be investigated and confirmed using advanced methods.

Measles, mumps and rubella are viral infectious diseases that may result in serious complications. Since the production of vaccines, the number of cases of these diseases has been dropped. Nevertheless, these infectious diseases are still one of the major health problems in developing countries. In this study, in order to evaluate the protective responses against measles, mumps and rubella, the level and avidity of virus-specific IgG antibodies were measured in 53 medical students of Tehran University, aged between 20-30 years. Except for mumps vaccine, all the students had been vaccinated against measles and rubella according to Iran’s nationwide mass vaccination protocol for all persons aged 5–25 in 2003. Our results showed that 96.2% of the volunteers had a protective level (>1 IU/ml) of IgG against rubella, 79.2% had a protective level (>11 IU/ml) of IgG against measles and 64.16% had a protective level (>11 IU/ml) of IgG against mumps. Over ten years after nationwide measles-rubella vaccination campaign, most young adults aged 20-30 had protective levels of humoral immunity against measles and rubella. However, Iranian young population is still unvaccinated against mumps, and therefore relatively large number of young adults had no protective level of IgG against it. This finding may be due to reduction in circulating of wild strain. We recommend screening of medical students for immunity against infectious agents such as measles, mumps, rubella, because they are at a high risk of these infectious agents.

The Plaque Forming Unit(PFU) and Tissue Culture Infectious Dose50(TCID50) methods are used for evaluation of vaccine heat stability and effect of various stabilizers on thermal stability of vaccines. The aim of present study is using Real-Time PCRtechniquefor estimation of vaccine degradation rate and thermal stability of measles vaccines. Lyophilized measles vaccines containing three various stabilizers were reconstituted with distilled water. Three vial of each vaccine incubated at25˚C for 0, 4 and 8 hours. Titer of virus in vaccines calculated by TCID50 method. Also after RNA Extraction and cDNA synthesis, the RNA copy numbers of viruses in vaccines were estimated by absolute quantitative Real-Time PCRtesting. The data were analyzedby SPSS 19 and Sigma Plot 11 software.The result of this study showed there is a significant relationshipbetween vaccine degradation rate calculated with TCID50 and Real-Time PCR method (p<0.05). ThereforeReal-Time PCR is a good complement or appropriate replacement to traditional methods.Titration methods based on cell culture are gold tests for titration of viral vaccines and estimation of heat stability but Real-Time PCR technique can also be used for this goals. This method is faster, cheaper and easier than TCID50.

The importance of human papillomavirus (HPV) in developing of cervical cancer has been proved. Among HPVs، human papillomavirus type 16 (HPV-16) is accounted for in the first place in cervical cancer. So screening the human papillomavirus type 16 particularly is important. This study investigated the presence of HPV-16 in the ThinPrep samples collected from 11 provinces of Iran. This cross sectional study was conducted on 108 ThinPrep samples which were included HPV DNA. The DNA of samples was extracted by Invitek kit. Then HPV-16 genome was sought using primers corresponding to the parts of the E6/E7 genome of HPV-16 by Nested PCR method. Data were analyzed using SPSS software version 13. 25% of samples (27 out of 108) were positive for HPV-16. Kerman province had the most rate of HPV-16 positive with having four HPV DNA positive samples and Qazvin province had the lowest rate of HPV-16 positive with having seven HPV DNA positive. HPV-16 is the most important and prevalent type of HPV among Iranian woman and identification of the other high-risk HPV types is highly recommended.

Noticing the sensitivity of measles virus to temperature and light, maintaining its stability is highly important in live vaccines. The aim of the study is to evaluate the stability of measles vaccine produced by AIK-C strain. In this experimental study, three lyophilized vaccine vials were incubated at 37˚C for one week and their stability was evaluated via accelerated test. In addition, reconstituted vaccines were incubated at 4˚C, 25˚C, and 37˚C for 0, 4, 8, 12, 16 hours after reconstitution and their remaining infectious virus titer was measured using CCID50 method. Half-life of the reconstituted measles vaccine was evaluated according to linear regression analysis. When the reconstituted vaccine was incubated at 4˚C, 25˚C, and 37˚C, the titer loss per hour was equal to 0.05, 0.1 and 0.2 Log10 CCID50, respectively. Also, the half-life of this vaccine at these temperatures was 5.31, 2.26, and 1.36 hours, respectively. The loss of potency for measles vaccine produced by AIK-C strain is 0.33 Log after storage at 37°C for one week, while the reported amounts for commercial vaccines such as Mevilin-L, Attenuvax, Edmonston-Zagreb, and Rimevax are 0.7, 0.7, 1 and 0.78, respectively. Lyophilized and reconstituted vaccine containing AIK-C strain is more stable in comparison with Edmonston B, Schwartz, Biken-CAM, and Leningrad strains. The stability of the reconstituted AIK-C strain vaccine is similar to Moraten strain at 37˚C.

Varicella–zoster virus (VZV) causes herpes zoster and varicella(Chicken-pox), usually a mild disease which is diagnosed clinically with few complications. However, in neonates and healthy adults it can have a severe presentation. Herpes zoster results from VZV reactivation later in life. To determine the seroprevalence of VZV in elementary school children aged 6-10 years in Shiraz, Iran. A cross-sectional seroprevalence survey was conducted on 270 healthy subjects. All serum samples were investigated for immunoglobulin G (IgG) antibody against VZV using a commercial enzyme linked immunosorbent assay (ELISA). Among the studied population, 175 (64.8%) had no detectable antibody levels. The overall seroprevalence rate was 35.2%. A breakdown of seropositivityto VZV according to age was as follows; 10 years old, 50%, 9 years old, 48.2%, 8 years old, 27.3%, 7 years old, 32.1%, and 6 years old, 13.2%. As VZV susceptibility in the studied age groups was higher than the expected rate, therefore childhood VZV vaccination is recommended in our region.