Vaccine Research
Volume:6 Issue: 1, Winter and Spring 2019

Pertussis or whooping cough is one of the vaccine preventable diseases. The purpose of this study was to evaluate the seroepidemiology of pertussis in two groups of children (i.e. under 2 months and 2-12 months old) who had been admitted to Tehran Children Hospital.

Sampling from the children was done along with completing a questionnaire including demographic information, clinical symptoms and the history of the parents coughing. The
levels of IgG-Ptx antibody were then measured using the children's sera.

Overall, 10.8% of the children were not immune, 78.3% were immune, and 10.9% had recent pertussis infections. Moreover, 19.4% of the female and 13.1% of the male subjects had the infection. In the age group less than two months, 16.6% were infected. The likelihood of new infection among the children less than 2 months old was 1.2 times higher than the control group (P < 0.004). Fifty percent of the children who were diagnosed with cyanosis in their clinical examinations had a recent infection (P <0.001). 

Pertussis appears to be endemic in Iran with children under one year old being at high risk of the infection. In this regard, maternal vaccination against pertussis for conferring passive immunity to the newborns could be considered as a protection measure.

Avian necrotic enteritis (NE) is a multi-virulence disease caused by the bacterium Clostridium perfringens. Several toxins of this bacteria are components of different candidate vaccines, and have been considered as important factors in pathogenesis of NE. A fusion subunit protein composed of immunodominant segments of NetB, Alpha-toxin and metallopeptidase proteins (NAM) was designed. The high level production of NE subunit vaccine candidate is important for the in vitro and in vivo evaluation and later to decrease the production costs. Therefore, the Response Surface Methodology (RSM) was used for optimizing E. coli culture condition. To this end, induction conditions including cell optical density prior induction (OD600nm), IPTG concentration, post-induction temperature and time were modified. The statistical analysis revealed that all variables except IPTG had significant effects on production and solubility of rNAM. A 7.39 fold increase in production of soluble rNAM was achieved when the post induction temperature, IPTG concentration, the pre-induction OD and time were 19 ºC, 0.55 mM, 0.8 respectively in 8 h after induction. Our study indicated that the RSM method is a simple and superior strategy for protein expression improvement which is considered as a major limitation in production of vaccine candidate and other recombinant proteins using different hosts.

The global co-circulation of two influenza B virus genetic lineages known as B/Yamagata and B/Victoria may lead to a mismatch between the circulating virus and the strain recommended for use in influenza vaccines. Little is known about the protective efficacy of unmatched influenza B strains, especially when it comes to live attenuated influenza vaccine. The main purpose of this study was to demonstrate the viability of using live attenuated influenza vaccine developed on B/USSR/60/69 backbone to protect from heterologous influenza B challenge infection.

To estimate the potential cross-protective activity of mono- and trivalent live attenuated vaccines based on B/Victoria or B/Yamagata genetic lineage virus against a heterological challenge. Ferrets were given one dose of vaccine and then challenged with influenza B virus and monitored for clinical signs associated with influenza infection. Samples of the ferrets’ airways were tested for the presence of challenge virus.

Mono- and trivalent live attenuated influenza vaccines were shown to be safe and cross-protective against genetically different influenza B viruses based on virological and histological data and clinical signs. A lower titer of heterologous challenge virus in the airways of vaccinated ferrets compared to mock-vaccinated animals inoculated with challenge virus was detected. Interestingly, B/Victoria-based vaccines were more cross-protective compared with B/Yamagata-based vaccines.

In the case of mismatches of B component of the trivalent live attenuated influenza vaccine and lineage of the circulating influenza B viruses, one of the options could be using trivalent preparation containing a B/Victoria lineage component.

Pseudomonas aeruginosa (PA) is an opportunistic mucosal human pathogen responsible for a wide range of acute and chronic infections. PA releases outer membrane vesicles (OMVs) in all situations and environments. OMVs are bilayered proteolipids ranging in diameter from 50 to 250 nm. Recent studies have demonstrated that OMVs are related to PA pathogenesis. According to strain-dependent components of OMV, in this study, we aimed at identifying significant physicochemical differences among OMVs from lab strain ATCC 17933, an antibiotic-susceptible and an antibiotic-resistant PA clinical strains.

OMVs of the three strains were purified using differential centrifugation with deoxycholate and EDTA. Chemical analyses were assessed using nano-drop, SDS-PAGE and the limulus amebocyte lysate (LAL) test. Moreover, electron microscopy was performed to verify the stability and totality of the extracted OMVs.

The nanodrop method and the LAL test showed that total protein and endotoxin concentrations were significantly different among all the 3 mentioned strains. In addition, the quality control of OMVs illustrated that the lab and the antibiotic-susceptible strains were approximately similar in terms of the vesicle yield and size; however they differed in protein contents. Moreover, OMVs generated from the resistant strain had a higher density, smaller size and sharper protein bands as observed by electron microscopy and SDS-PAGE, respectively. Endotoxins measurement were 2.8, 2.9 and 3 EU/ml for OMVs from the lab, the antibiotic-susceptible and the resistant strains, respectively.

The results of the current study demonstrated that OMVs of the resistant PA strain may produce vesicles with a particular composition. This characterization profile provides a basis for future studies to elucidate immune responses to OMVs from PA and developing vaccines against Pseudomonal infections as a common nosocomial infection with extremely high resistance to antibiotics.

The bacillus Calmette‐Guérin (BCG) vaccine against pulmonary tuberculosis (TB) remains with poor protective efficacy. However BCG is the only licensed vaccine against human TB. This review discusses the main research progress in the field of TB vaccine development and will summarize the current status, and main challenges for the development of a safer and more efficient TB vaccine.

The 100-year-old Pasteur Institute of Iran is a research, manufacturing, and educational institute that aims to provide public health. It has taken great steps towards producing vaccines in Iran. The institute has played an important role in controlling infectious diseases in Iran by producing a great number of vaccines such as smallpox, cholera, Bacillus Calmette–Guérin (BCG), and recombinant hepatitis B along with infectious disease control programs and diagnostic laboratories. The institute is currently pursuing a program to develop its production lines for human polysaccharide-conjugate vaccines and viral vaccines for the health system of Iran.
This paper reviews manufacturing activities of this institute over the past 100 years.

To date, while many studies have investigated antiviral agents or vaccines against HIV, success has been limited. In this field, mutagenesis of the viral genome often contributes to viral escape from the antiretroviral therapies and the emergence of HIV-1 strains resistant to the drugs. Therefore, developing alternative methods, including more effective vaccines, antiviral therapies (such as RNAi therapy) and delivery systems, seems to be necessary to compensate for these issues. The aim of this study was to establish an efficient system for siRNA delivery as a safe anti-HIV therapeutic approach.

In this research, the use of chitosan-coated SPION was investigated as a method for RNA delivery. So, after generating a stable cell line of HEK293 (expressing HIV-1 tat), we designed a potent siRNA against HIV-1 tat, and then the effectiveness of the modified SPION in siRNA delivery to HEK293 cells was evaluated.

The results of this study showed that the optimal concentration (50 µg/mL) of the modified SPION containing anti-tat siRNA (with a range size of 50-70 nm and average zeta potential of +25 mV) were significantly internalized into the cells and decreased the expression of HIV-1 tat over than 80%. Moreover, the nanoparticles showed no considerable toxicity on the cells.

It would be concluded that SPION could be optimized as a probable RNA/vaccine delivery system into target cells. Therefore, this study offers a therapeutic strategy against HIV or other infectious diseases.