Objectives: The World Health Organization recently revised their recommendations and considered healthy children and adolescents as low priority group for COVID-19 vaccine. This review comprehensively assessed existing clinical evidence on COVID-19 vaccine in 12-17 years old. Methods: Included in this review were any type of study that investigated the efficacy, immunogenicity, safety, and effectiveness of COVID-19 vaccine on protection against SARS-COV-2 infection in 12-17 years old. Various electronic databases were searched up to March 15, 2023. Studies were screened, data extracted, risk of bias appraised, and certainty of evidence was judged using GRADE. Review Manager 5.4 was used to estimate pooled effects. Difference between the two groups was described as mean difference for continuous variables and as relative risk or odds ratio for categorical variables. Results: There were six randomized controlled trials and 16 effectiveness studies (8 cohorts and 8 case control). Low certainty evidence showed that BNT162b2 (Pfizer) was effective, immunogenic, and safe in healthy adolescents. There were 15 effectiveness studies on BNT162b2 (Pfizer) in healthy adolescent and one on immunocompromised patients. It was protective against infection with any of the variants, with higher protection against Delta than Omicron. BNT162b2 is protective against hospitalization and emergency and urgent care (high certainty); and critical care and MIS-C (low). Very low certainty evidence noted that BNT 162b2 was also immunogenic in 12-21 years old with rheumatic diseases while on immunomodulatory treatment but with possible increased exacerbation of illness. Low certainty evidence demonstrated that mRNA-1273 (Moderna) was effective, immunogenic, and safe. Low to very low certainty evidence were noted on the safety and immunogenicity of two vector base vaccines (ChAdOx1-19 and Ad5 vector COVID vaccine) and two inactivated vaccines (CoronaVac and BBIBP CorV). Conclusion There is presently low certainty evidence on the use of RNA vaccines in 12-17 years old. The recommendation on its use is weak. There is presently insufficient evidence for the use of inactivated and vector-based COVID-19 vaccines. Different countries should consider whether to vaccinate healthy adolescent without comprising the other recommended immunization and health priorities that are crucial for this age group. Other factors including cost-effectiveness of vaccination and disease burden should be accounted.
mRNA Vaccines ; Vaccines, Inactivated

The application of the cholera vaccine is one of the cholera prevention and control strategies. Cholera vaccines stimulate mucosal immune to play the role of antibacteria and antitoxin. When the cholera toxin B subunit is added in the cholera vaccine, it could also defend against some diarrhea associated pathogens by cross-protection. Oral inactivated cholera vaccines are commercially available now. The oral live vaccine candidates are under development. The development of cholera vaccine is not only on the technical aspect, based on the situations of epidemic areas and population, cost, storage and transportation condition should also be considered. Though the argument on the use of cholera vaccine in epidemic areas and population in high risk existed previously, its vaccination has reached agreement now based on the clinical trials and evaluations during epidemic period.
Administration, Oral ; Cholera ; Cholera Toxin ; Cholera Vaccines ; Cross Protection ; Diarrhea ; Humans ; Vaccination ; Vaccines, Attenuated ; Vaccines, Inactivated

Japanese encephalitis (JE) virus is the leading cause of vaccine-preventable encephalitis in Asia and the Western Pacific, which mainly invades central nervous system. Vaccination is the most important strategy to prevent JE. Currently, both live attenuated Japanese encephalitis vaccines (JE-L) and inactivated vaccines (JE-I) are in use. Due to the supply of vaccines and the personal choice of recipients, there will be a demand for interchangeable immunization of these two vaccines. However, relevant research is limited. By reviewing domestic and foreign research evidence, this article summarizes the current situation of the interchangeable use of JE-L and JE-I, and makes recommendations when the interchangeable immunization is in urgent need, so as to provide reference for practical vaccination and policymaking in China.
Encephalitis Virus, Japanese ; Encephalitis, Japanese/prevention & control* ; Humans ; Immunization ; Japanese Encephalitis Vaccines ; Vaccination ; Vaccines, Inactivated

Humans ; Vaccines, Inactivated ; COVID-19/prevention & control* ; Vaccination ; Viral Vaccines ; Immunity ; Antibodies, Viral

EV71 infection has become a serious public health threat especially among young children. Yet, at present, no specific antiviral drug against EV71 infection is available. A number of scientists are studying various kinds of vaccines, including inactivated vaccine, virus-like particle vaccine, DNA vaccine, synthetic peptide vaccines, and transgenic oral vaccine. This article reviews the recent advancement in the design of various kinds of vaccine against EV71 as well as their prospective usefulness, effectiveness, weakness and developments in the foreground.
Enterovirus A, Human ; immunology ; Hand, Foot and Mouth Disease ; immunology ; prevention & control ; Humans ; Vaccines, Attenuated ; immunology ; Vaccines, DNA ; immunology ; Vaccines, Inactivated ; immunology ; Vaccines, Synthetic ; immunology ; Viral Vaccines ; immunology

OBJECTIVETo investigate the effect of temperature on the stability of intermediate and final products of inactivated enterovirus 71 vaccine, which was prepared in human diploid cells.

METHODSThe different batches of harvest viral cultures, the vaccine stock solutions and the final productions of inactivated enterovirus 71 vaccine were stored at different temperatures. The samples of viral culture stored at -20°C or 4°C were harvested at 0, 6, 12 and 24 months later. The samples of vaccine stock solutions stored at -20°C were harvested at 0, 6, 12 and 24 months later, and that stored at 4°C were harvested at 0, 1, 3, 6 and 12 months later. The samples of finial products were harvested at different time points (0, 6, 12 and 24 months for storing at 4°C; 0, 7, 14, 28, 42 and 60 d for storing at 25°C; 0, 3, 7, 14 and 21 d for storing at 37°C). The viral titer, antigen content, antigen purity, endotoxin content, effectiveness, pH and appearance of samples were determined, respectively. A total of 1 800 BLAB/c mice were immunized by vaccine and 150 control mice were injected by diluents without antigen via intraperitoneal. The tail vein blood (500 µl per mouse) from 1 950 mice were harvested after 4 weeks post injected. The neutralization antibody titers of the serum were tested to calculate the half effective dose (ED50) of final products. All results were analyzed using analysis of variance to compare the differences of the above indexes.

RESULTSThe viral titers of harvest viral culture of inactivated EV71 vaccine were (6.67 ± 0.13), (6.56 ± 0.09), (6.52 ± 0.04), (6.39 ± 0.16) lgCCID50/ml (CCID50, the half cell culture infective dose) after 0, 6, 12 and 24 months storage at -20°C; and (6.67 ± 0.13), (6.41 ± 0.13), (6.19 ± 0.18), (5.97 ± 0.09) lgCCID50/ml at 4°C. The viral titers reduced with time (F = 9.81 or 44.16, P < 0.05). The antigen contents of the vaccine stock solution were maintained at (3 626.67 ± 1 382.56) EU/ml within 3 months at 4°C, but were (2 080.00 ± 876.36), (951.17 ± 346.35) EU/ml at 6 and 12 months, respectively. The ED50 of the final production were (31.00 ± 2.71), (32.93 ± 3.22), (39.37 ± 3.44) and (46.04 ± 3.25) EU/ml after 0, 6, 12 and 24 months storage at 4 °C, but were (31.00 ± 2.71), (32.23 ± 2.66), (34.70 ± 1.77), (40.04 ± 2.10), (47.78 ± 1.93) and (56.97 ± 0.50) EU/ml at 0, 7, 14, 28, 42 and 60 days at 25°C, and were (31.00 ± 0.00), (36.20 ± 0.00), (41.87 ± 0.50), (53.25 ± 0.50) and (64.84 ± 0.58) EU/ml at 0, 3, 7, 14 and 21 days at 37°C, respectively. The ED50 had increased with the time by and had significantly differences compared with the beginning level (F = 28.49, 215.15 or 156.12, P < 0.05).

CONCLUSIONThere is a good stability of the intermediate and final productions of inactivated enterovirus 71 (EV71) vaccines, within 24 months at -20°C or 6 months at 4°C storage for viral culture, 24 months at -20°C or 3 months at 4°C storage for stock solution and 24 months at 4°C or 28 d at 25°C or 7 d at 37°C storage for finial vaccine.

Animals ; Drug Storage ; methods ; Enterovirus A, Human ; Humans ; Immunization ; Mice ; Vaccination ; Vaccine Potency ; Vaccines, Inactivated

PURPOSE: Porcine reproductive and respiratory syndrome virus (PRRSV) leads to major economic losses in the swine industry. Vaccination is the most effective method to control the disease by PRRSV. MATERIALS AND METHODS: In this study, the efficacy of a glycoprotein (GP) 5-modified inactivated vaccine was investigated in pigs. The study was performed in three farms: farm A, which was porcine reproductive and respiratory syndrome (PRRS)-negative, farm B (PRRS-active), which showed clinical signs of PRRS but had not used vaccines, and farm C (PRRS-stable), which had a history of endemic PRRS over the past years, but showed no more clinical signs after periodic administration of modified live virus vaccine. RESULTS: The inactivated vaccine induced great enhancement in serum neutralizing antibody titer, which was sufficient to protect pigs from further infections of PRRSV in a farm where pre-existing virus was circulating. CONCLUSION: These results indicated that vaccination with the inactivated vaccine composed of viruses possessing deglycosylated GP5 would provide enhanced protection to pigs from farms suffering from endemic PRRSV.
Antibodies, Neutralizing ; Glycoproteins ; Neutralization Tests ; Porcine Reproductive and Respiratory Syndrome* ; Porcine respiratory and reproductive syndrome virus* ; Swine* ; Vaccination ; Vaccines ; Vaccines, Inactivated

One of the major cause of recent acute viral hepatitis in Korean adults is hepatitis A virus (HAV) infection. Most of hepatitis A cases are young adults in their twenties or thirties, and the severity of the disease is related to the age of patients. The seroprevalence of HAV among the adolescents and young adults in their teens and twenties is about 10%, which suggests that a growing number of young adults are susceptible to HAV infection. Development of more adult cases with severe presentation is expected in the near future, and some preliminary data suggest the incidence rate of hepatitis A in Korea might be higher than 20/100,000 population. This clinical features and the epidemiological shift of HAV urge to promote childhood vaccination and consider catch-up vaccination for adolescents and young adults. More extensive evaluation on the nationwide epidemiology of HAV infection, cost-benefit analysis of HAV vaccination, and setting-up of guidelines for HAV vaccination are urgently warranted.
Adolescent ; Adult ; Child ; Hepatitis A/immunology/*prevention & control ; Hepatitis A Antibodies/immunology ; *Hepatitis A Vaccines ; Humans ; Immunization Schedule ; Korea ; Seroepidemiologic Studies ; Vaccines, Inactivated

Despite recent innovative advances in molecular virology and the developments of vaccines, influenza virus remains a serious burden for human health. Vaccination has been considered a primary countermeasure for prevention of influenza infection. Live attenuated influenza vaccines (LAIVs) are particularly attracting attention as an effective strategy due to several advantages over inactivated vaccines. Cold-adaptation, as a classical means for attenuating viral virulence, has been successfully used for generating safe and effective donor strains of LAIVs against seasonal epidemics and occasional pandemics. Recently, the advent of reverse genetics technique expedited a variety of rational strategies to broaden the pool of LAIVs. Considering the breadth of antigenic diversity of influenza virus, the pool of LAIVs is likely to equip us with better options for controlling influenza pandemics. With a brief reflection on classical attenuating strategies used at the initial stage of development of LAIVs, especially on the principles underlying the development of cold-adapted LAIVs, we further discuss and outline other attenuation strategies especially with respect to the rationales for attenuation, and their practicality for mass production. Finally, we propose important considerations for a rational vaccine design, which will provide us with practical guidelines for improving the safety and effectiveness of LAIVs.
Antigenic Variation ; Cross Protection ; Humans ; Influenza Vaccines ; Influenza, Human ; Orthomyxoviridae ; Pandemics ; Reverse Genetics ; Seasons ; Tissue Donors ; Vaccination ; Vaccines, Inactivated

BACKGROUNDThe etiologic agent of severe acute respiratory syndrome (SARS) has been confirmed to be a novel coronavirus (CoV), namely SARS-CoV. Developing safe and effective SARS-CoV vaccines is essential for us to prevent the possible reemergence of its epidemic. Previous experiences indicate that inactivated vaccine is conventional and more hopeful to be successfully developed. Immunogenicity evaluation of an experimental inactivated SARS-CoV vaccine in rabbits was conducted and reported in this paper.

METHODSThe large-scale cultured SARS-CoV F69 strain was inactivated with 0.4% formaldehyde and purified, then used as the immunogen combined with Freund's adjuvant. Eight adult New Zealand rabbits were immunized four times with this experimental inactivated vaccine. Twelve sets of rabbit serum were sampled from the third day to the seventy-fourth day after the first vaccination. The titers of specific anti-SARS-CoV IgG antibody were determined by indirect enzyme-linked immunosorbent assay, and the neutralizing antibody titers were detected with micro-cytopathic effect neutralization test.

RESULTSRapid and potent humoral immune responses were induced by the inactivated SARS-CoV vaccine in all the eight test rabbits. Titers of both specific IgG antibody and neutralizing antibody peaked at about six weeks after first vaccination, with the maximum value of 1:81 920 and 1:20 480, respectively. After that, serum antibody levels remained at a plateau or had a slight decrease, though two boosters were given in the succedent 4 to 5 weeks. Cross neutralization response existed between SARS-CoV F69 strain and Z2-Y3 strain.

CONCLUSIONSThe inactivated SARS-CoV vaccine made from F69 strain owns strong immunogenicity, and the cross neutralization response between the two different SARS-CoV strains gives a hint of the similar neutralizing epitopes, which provide stable bases for the development of inactivated SARS-CoV vaccines.

Animals ; Antibodies, Viral ; blood ; Immunoglobulin G ; blood ; Neutralization Tests ; Rabbits ; SARS Virus ; immunology ; Vaccines, Inactivated ; immunology ; Viral Vaccines ; immunology