Humans ; Mass Vaccination ; COVID-19 Vaccines/therapeutic use* ; COVID-19/prevention & control* ; Immunity, Herd ; Vaccination

PURPOSE: Neisseria meningitidis and Neisseria gonorrhoeae share between 80% and 90% of their genetic sequence. Meningococcal serogroup B vaccines based on outer membrane vesicles—such as VA-MENGOC-BC—could cross-protect against gonorrhea. The aim of this study was to analyze the incidence rates of gonorrhea and other sexually transmitted diseases with respect to the use of the VA-MENGOC-BC vaccine. MATERIALS AND METHODS: Health statistics between 1970 and 2017 were reviewed and the incidence of meningococcal disease and sexually transmitted diseases (gonorrhea, syphilis, condyloma acuminatum, hepatitis B and human immunodeficiency virus infection) were analyzed during the pre- and post-vaccination periods. Gonorrhea incidence was also analyzed by age groups. RESULTS: VA-MENGOC-BC was successfully used to control a meningococcal epidemic in Cuba. The strategy to combat the epidemic was carried out in two stages. The first one was a nationwide mass-vaccination campaign from 1989 to 1990, targeting the population at highest-risk aged 3 months to 24 years. During the second stage, begun in 1991, it was included in the Expanded Immunization Program. Gonorrhea incidence increased from 1970 to 1989. However, after the VA-MENGOC-BC massive vaccination campaign a sharp decrease of gonorrhea incidence was observed. It lasted between 1989 and 1993. A second incidence peak was detected in 1995, but it dropped again. Data clearly show a decline in the incidence of gonorrhea following massive vaccination, in contrast with other sexually transmitted diseases. Incidence rates in unvaccinated age groups also decreased, probably due to herd immunity. CONCLUSION: There is evidence that VA-MENGOC-BC could induce a moderate protection against gonorrhea.
Cuba ; Gonorrhea ; Hepatitis B ; HIV ; Humans ; Immunity, Herd ; Immunization Programs ; Incidence ; Membranes ; Neisseria gonorrhoeae ; Neisseria meningitidis ; Serogroup ; Sexually Transmitted Diseases ; Syphilis ; Vaccination ; Vaccines

Until 1995, the incidence of symptomatic acute hepatitis A was minimal and there were no cases of national outbreak in Korea. However, there was a nationwide outbreak of hepatitis A that peaked in 2009. In 2019, a total of 10,083 cases of acute hepatitis A were reported for seven months of the year according to the Korea Center for Disease Control and Prevention. This may be attributed to the proportion of susceptible subjects in the Korean population, as about 10 years have passed since herd immunity was induced by the epidemic occurring during the late 2000s. Recent studies have shown that the rate of seropositivity for anti-hepatitis A virus antibodies (anti-HAV) is the lowest in adults in their 20s and has not changed much over the past 10 years, and seropositivity of anti-HAV in adults in their 30s has continued to decline from 69.6% in 2005 to 32.4% in 2014. Most young adults who have not yet experienced hepatitis A and are not vaccinated are vulnerable to hepatitis A infection. This year's epidemic of hepatitis A is a predictable outcome for vulnerable populations. Therefore, effective acute hepatitis A control and prevention strategies are needed, particularly for those in their 20s and 30s.
Adult ; Antibodies ; Centers for Disease Control and Prevention (U.S.) ; Hepatitis A Antibodies ; Hepatitis A ; Hepatitis ; Humans ; Immunity, Herd ; Incidence ; Korea ; Prevalence ; Vulnerable Populations ; Young Adult

Outbreaks of porcine reproductive and respiratory syndrome virus (PRRSV) in vaccinated sow herds from occurrence to stabilization were monitored and analyzed in terms of serology and reproductive performance. Three different conventional pig farms experienced severe reproductive failures with the introduction of a type 1 PRRSV. These farms had adopted mass vaccination of sows using a type 2 PRRSV modified live vaccine (MLV). Therefore, to control the type 1 PRRSV, an alternative vaccination program utilizing both type 1 and type 2 MLV was undertaken. Following whole herd vaccinations with both types of MLV, successful stabilization of PRRS outbreaks was identified based on serological data (no viremia and downward trends in ELISA antibody titers in both sows and suckling piglets) and recovery of reproductive performance. Additionally, through comparison of the reproductive parameters between outbreak and non-outbreak periods, it was identified that PRRSV significantly affected the farrowing rate and the number of suckling piglets per litter at all three pig farms. Comparison of reproductive parameters between periods when the different vaccination strategies were applied revealed that the number of piglets born in total and born dead per litter were significantly increased after the introduction of the type 1 PRRS MLV.
Agriculture ; Disease Outbreaks ; Enzyme-Linked Immunosorbent Assay ; Immunity, Herd ; Immunity, Heterologous ; Mass Vaccination ; Porcine Reproductive and Respiratory Syndrome ; Porcine respiratory and reproductive syndrome virus ; Vaccination ; Viremia

The importance of vaccine on public health is related to the herd protection related to the levels of vaccine coverage, which directly influences the vaccinated individuals as well as the unvaccinated community. Reaching the level of herd protection by increasing vaccine coverage is the basic strategy to eradicate related infectious diseases. Again, herd protection has played an important role in public health practices. With the increasing interests in estimating the vaccine herd protection, we however, have seen only few relevant papers including observational population-based and cluster-randomized clinical trials reported in China. We hope to discuss the study designs for evaluating the vaccine herd protection in order to generate evidence-based related research in this field.
China/epidemiology* ; Communicable Disease Control ; Communicable Diseases/immunology* ; Humans ; Immunity, Herd/immunology* ; Research Design ; Vaccination/trends* ; Vaccines/immunology*

The epidemiology of human group A rotavirus was analyzed by examining genotypic data acquired from 1989 to 2009 in South Korea. This information was derived from all the available published articles on rotavirus studies in South Korea, retrieved from both the PubMed and KoreaMed databases. Four common G types (G1, G2, G3, and G4) and three common P types (P[8], P[4], and P[6]) accounted for approximately 93% and 99% of the rotavirus reports, respectively. The G9 type was frequently detected after 2000, and because of this prevalence, it is considered to be the fifth most important G type rotavirus after the G1.G4 genotypes. Less common G types of the virus such as G12, G11, and G10 were detected in some geographic settings, and it is important to consider the context of these subtypes and their epidemiological significance. The P[9] virus genotype was observed in the study and has been discussed in many other studies; however, the P[3], P[10] and P[25] genotypes were rarely detected in the epidemiological research. In general, the distributions of the G and P genotypes showed temporal and geographical fluctuations, and a nationwide rotavirus vaccine program that targeted these genotypes demonstrated effectiveness in protecting against the circulating rotavirus strains. However, further analysis is needed to determine the true long-term effectiveness of these vaccines; the analysis should also consider the unexpected effects of vaccinations, such as vaccine-induced diseases, herd immunity, and changes in host susceptibilities.
Epidemiology ; Genotype* ; Humans ; Immunity, Herd ; Prevalence* ; Republic of Korea* ; Rotavirus* ; Vaccination ; Vaccines ; Viruses

Pertussis is a pediatric infectious disease with one of the highest degrees of infectivity. Although pertussis may cause asymptomatic infections in children and adults with immunity, it can cause life-threatening diseases in newborn babies or infants. We report three cases of pertussis in infants <3 months of age without DTaP immunization who have received symptomatic treatment with the diagnosis of bronchiolitis from other hospitals, and subsequently correctly diagnosed and treated. The patients did not have the characteristic whooping cough, but the main symptoms were episodic cough, intermittent vomiting, and cyanosis. Based on culture results for Bordetella pertussis and PCR, pertussis was diagnosed and treated without any complications. As it is assumed that adults, adolescents, and asymptomatic patients may serve as sources of infection, immunization with Tdap vaccine is recommended to prevent dissemination of pertussis from adolescents and adults to infants, and thus maintain herd immunity.
Adolescent ; Adult ; Asymptomatic Infections ; Bordetella pertussis ; Bronchiolitis ; Child ; Communicable Diseases ; Cough ; Cyanosis ; Humans ; Immunity, Herd ; Immunization ; Infant ; Infant, Newborn ; Polymerase Chain Reaction ; Vomiting ; Whooping Cough

INTRODUCTIONWe undertook a study to evaluate the effectiveness of the National Childhood Immunisation Programme (NCIP) over the past 26 years by reviewing the epidemiological trends of the diseases protected, the immunisation coverage and the changing herd immunity of the population during the period of 1982 to 2007.

MATERIALS AND METHODSThe epidemiological data of all cases of diphtheria, pertussis, poliomyelitis, measles, mumps, rubella and acute hepatitis B notified to the Communicable Diseases Division, Ministry of Health (MOH) from 1982 to 2007 were collated and analysed. Data on tuberculosis (TB) cases were obtained from the TB Control Unit, Tan Tock Seng Hospital. Cases of neonatal tetanus and congenital rubella syndrome (CRS) among infants born in Singapore were identified from the Central Claims Processing System. The number of therapeutic abortions performed for rubella infections was retrieved from the national abortion registry. Coverage of the childhood immunisation programme was based on the immunisation data maintained by the National Immunisation Registry, Health Promotion Board. To assess the herd immunity of the population against the various vaccine-preventable diseases protected, the findings of several serological surveys conducted from 1982 to 2005 were reviewed.

RESULTSThe incidence of vaccine-preventable diseases covered under the NCIP had declined over the last 26 years with diphtheria, neonatal tetanus, poliomyelitis and congenital rubella virtually eliminated. The last case of childhood TB meningitis and the last case of acute hepatitis B in children below 15 years were reported in 2002 and 1996, respectively.

CONCLUSIONThe NCIP has been successfully implemented as evidenced by the disappearance of most childhood diseases, excellent immunisation coverage rate in infants, preschool and school children, and high level of herd immunity of the childhood population protected.

Adolescent ; Adult ; Child ; Child, Preschool ; Communicable Disease Control ; statistics & numerical data ; trends ; Communicable Diseases ; epidemiology ; Disease Notification ; statistics & numerical data ; Humans ; Immunity, Herd ; Immunization Programs ; statistics & numerical data ; Incidence ; Infant ; Population Surveillance ; Prevalence ; Singapore ; epidemiology

OBJECTIVES: The incidence of clinical hepatitis A has increased in young Korean adults since the mid-1990s. Although hepatitis A vaccinations have been administered in private clinics over the past 10 yr, no data exist on the vaccination rate and relating factors. METHODS: In 2005, a population-based survey of 12-35-month-old children was carried out in Nonsan, Korea. An interview survey was completed for 71.3% of the children. All data came from a vaccination card or confirmation from a provider. RESULTS: The hepatitis A vaccination rate was 42.3% for > or =1 dose and 24.7% for 2-dose. The results of the multivariate regression analysis for the hepatitis A vaccination showed that the second (OR=1.6) and third and successive children (OR=3.3) were less often immunized than the first child. Low economic status (OR=1.6), rural area (OR=1.5) and employed mother (OR=1.5) were also correlated with a lower vaccination rate. The hepatitis A vaccination rate was significantly lower in children who had no other vaccinations: measlesmumps-rubella (OR=2.8 for > or =1 dose and 7.3 for 2-dose), varicella (OR=20.2 and 22.0, respectively) and Haemophilus influenza type b (OR=14.3 and 13.3, respectively). CONCLUSION: To prevent outbreaks of clinical hepatitis A by enough herd immunity, a vaccination should be included in the National Immunization Program and a vaccination policy developed and implemented that can overcome the barriers to immunization such as late birth order and a mother's employment.
Adult ; Birth Order ; Chickenpox ; Child ; Disease Outbreaks ; Employment ; Haemophilus ; Hepatitis ; Hepatitis A ; Humans ; Immunity, Herd ; Immunization ; Immunization Programs ; Incidence ; Infant ; Influenza, Human ; Korea ; Mothers ; Porphyrins ; Risk Factors ; Vaccination

Streptococcus pneumoniae causes considerable morbidity and mortality. There are currently two types of pneumococcal vaccine available under license: pneumococcal polysaccharide vaccines(PPV23) and pneumococcal conjugate vaccines(PCV-7). PPV23 contains T-cell independent antigens which stimulate mature B lymphocytes and produce an effective antibody response. However T-lymphocytes are not involved which leads to an absence of immunological memory and lack of an anamnestic response on challenge. The 23-valent vaccine is reported to be effective in older children and adults, and is currently recommended for high-risk patients such as hyposplenic patients and the general elderly population. PPV23 appears cost effective for elderly patients PCV-7 has high efficacy against radiological pneumonia and invasive pneumococcal disease, acute otitis media, reduces the nasopharyngeal colonization rate of vaccine strain, and provides herd immunity. PCV-7 may also provide an effective new tool to reduce disease caused by drug-resistant strains of pneumococci. But this vaccine has limited serotype coverage, replacement phenomena. It remains unknown if long-term serotype shifts would be caused by PCV-7. And the possibility of the spread and acquisition of virulent non-vaccine serotypes is a real threat which must be monitored. New PCVs including more serotypes could prove to be good options in the future for all age groups. Several protein-based pneumococcal vaccine candidates (currently under investigation in animal models) offer the potential advantage of serotype independent protection in the near future.
Acute Disease ; Adult ; Aged ; Animals ; Antibody Formation ; B-Lymphocytes ; Child ; Colon ; Humans ; Imidazoles ; Immunity, Herd ; Immunologic Memory ; Nitro Compounds ; Otitis Media ; Pneumococcal Vaccines ; Pneumonia ; Sprains and Strains ; T-Lymphocytes