Vaccine-preventable Viral Infections Research Articles

A combined cross-sectional analysis and case-control study evaluating tick-borne encephalitis vaccination coverage, disease and vaccine effectiveness in children and adolescents, Switzerland, 2005 to 2022.

BackgroundTick-borne encephalitis (TBE) is a severe, vaccine-preventable viral infection of the central nervous system. Symptoms are generally milder in children and adolescents than in adults, though severe disease does occur. A better understanding of the disease burden and duration of vaccine-mediated protection is important for vaccination recommendations.AimTo estimate TBE vaccination coverage, disease severity and vaccine effectiveness (VE) among individuals aged 0-17 years in Switzerland.MethodsVaccination coverage between 2005 and 2022 was estimated using the Swiss National Vaccination Coverage Survey (SNVCS), a nationwide, repeated cross-sectional study assessing vaccine uptake. Incidence and severity of TBE between 2005 and 2022 were determined using data from the Swiss disease surveillance system and VE was calculated using a case-control analysis, matching TBE cases with SNVCS controls.ResultsOver the study period, vaccination coverage increased substantially, from 4.8% (95% confidence interval (CI): 4.1-5.5%) to 50.1% (95% CI: 48.3-52.0%). Reported clinical symptoms in TBE cases were similar irrespective of age. Neurological involvement was less likely in incompletely (1-2 doses) and completely (≥ 3 doses) vaccinated cases compared with unvaccinated ones. For incomplete vaccination, VE was 66.2% (95% CI: 42.3-80.2), whereas VE for complete vaccination was 90.8% (95% CI: 87.7-96.4). Vaccine effectiveness remained high, 83.9% (95% CI: 69.0-91.7) up to 10 years since last vaccination.ConclusionsEven children younger than 5 years can experience severe TBE. Incomplete and complete vaccination protect against neurological manifestations of the disease. Complete vaccination offers durable protection up to 10 years against TBE.

Changing demographics and immunity to vaccine preventable diseases in people with HIV in Ireland

BackgroundHIV infection is associated with an increased risk of morbidity and mortality from vaccine preventable infections. This research describes, in the context of changing patient demographics, the seroprevalence of vaccine preventable viral infections among attendees of the largest centre for HIV positive patients in Ireland.MethodsBaseline serum IgG results for measles, mumps, rubella, varicella zoster virus (VZV) & hepatitis A, as well as hepatitis B sAg, cAb and sAb results, were retrieved for 2534 clinic attendees attending in 2018. Results were available for between 990 and 2363 attendees (39–93%), depending on the test, and were compared with 2013 clinic data.ResultsThere was a 35% increase in attendees in 2018 when compared to 2013. The largest increase was in attendees of South American origin. In 2018, males accounted for 73% of the entire cohort and the HIV acquisition risk for 48% of attendees was MSM. 47% of attendees were originally from Ireland. Among those tested, 33% were susceptible to at least one component of the MMR vaccine. 5% were VZV non-immune (significantly associated with younger age and the acquisition risk status of injection drug use). 21% were hepatitis A non-immune (significantly associated with younger age and being of European or South American origin). 32% were hepatitis B cAb seropositive (significantly associated with older age, injection drug use status and being originally from Africa). 3% demonstrated hepatitis B sAg positivity. 64% had hepatitis B sAb ≥ 10mIU.ConclusionIn a cohort of attendees to an HIV clinic in a large urban setting, the susceptibility to several common vaccine preventable viral infections, in particular MMR and hepatitis A and B, was high. These results highlight the importance of proactive screening and immunisation to help protect this high risk patient group against vaccine preventable diseases.

Immunity to varicella, measles, and mumps in patients evaluated for lung transplantation

Vaccine-preventable viral infections are associated with increased risk of morbidity and mortality in post-transplant patients on immunosuppression regimens. Therefore, we studied rates of immunity against vaccine-preventable viruses in lungtransplantation(LTx) candidates and their associations with underlying lung disease and clinical characteristics. We retrospectively studied 1025 consecutive adult patients who underwent first-time evaluation for LTx at a single center between January 2016 and October 2018. Viruses studied included varicella zoster (VZV),measles, and mumps. Young age (17-48years old) was negatively associated with immunity for VZV (OR 4.54, p<.001), measles (OR 15.45, p<.001) and mumps (OR 3.1, p<.001), as compared to those 65+. Many LTx candidates with cystic fibrosis (CF) had undetectable virus-specific antibody titers including: 13.5% for VZV, 19.1% for measles, and 15.7% for mumps with significant odds of undetectable titers for VZV (OR 4.54, p<.001) and measles (OR 2.32, p=.010) as compared to those without CF. Therefore, a substantial number of patients undergoing LTx evaluation had undetectable virus-specific antibody titers. Our results emphasize the importance of screening for immunity to vaccine-preventable infections in this population and the need for revaccination in selected patients to boost their humoral immunity prior to transplantation.

Measles outbreak investigation in Ginnir district of Bale zone, Oromia region, Southeast Ethiopia, May 2019.

IntroductionMeasles is a vaccine-preventable viral infection of humans, primarily affecting children <5 years. During early 2019, outbreak of measles occurred in Ginnir district of Bale zone, Southeast Ethiopia. We investigated to describe the outbreak and identify risk factors.MethodsWe conducted a descriptive and 1:2 unmatched case-control study in Ginnir district from March 18 to April 29, 2019. Fifty-six cases and 112 controls were recruited. For descriptive study, we identified 1043 cases recorded on the line-list and for case-control study, cases were identified using national standard case-definition. Mothers of case-patients and controls were interviewed using structured questionnaire. We estimated vaccine efficacy (VE) from case-control study. We conducted bivariate and multivariable logistic regression.ResultsIn four-months period, a total of 1,043 suspected measles cases epidemiologically linked to five laboratory confirmed cases reported. Of which, 555 (53.2%) were males and 714 (68.5%) were <5 years. The median age of cases was 36 months (IQR=12-60 months). The overall attack rate (AR) was 63/10,000 population with case fatality ratio of 0.5% (5 deaths/1043). Infant <9 months were the most affected age groups (AR=31/1000). Majority (79%) of measles cases were not vaccinated against measles. Last-year (2017/18) administrative measle vaccine coverage of the district was 76.7%. Being unvaccinated against measles (AOR=5.4, 95%CI=2.2-13.4), travel history (AOR=4.02, 95%CI=1.2-13.6), contact with measles case-patient (AOR=5.6, 95%CI=2.12-14.4) and mothers knowledge of measles transmission (AOR=0.36, 95%CI=0.15-0.87) were associated with measles infection. VE in children aged 9-59 months was 90% (95%CI=69-97%).ConclusionThis confirmed measles outbreak was caused by failure to vaccinate, as indicated by the high VE, low administrative coverage, and 79% unvaccinated cases. Strengthening routine and supplementary immunization are required.

Viral seroprevalence in pediatric kidney transplant recipients.

Aim:Viral infections commonly affect kidney transplant recipients and may lead to graft failure and death. The aim of this study was to evaluate the antibody seroprevalence against viral agents in kidney transplant recipients.Material and Methods:The records of children who underwent kidney transplantation between 2008 and 2018 in Akdeniz University Faculty of Medicine were retrospectively reviewed. Epstein-Barr virus, cytomegalovirus, hepatitis A virus, hepatitis B virus, varicella, measles, rubella and mumps serologies evaluated before transplantation, were recorded. The clinical characteristics of seronegative and seropositive patients were compared, and factors that affected seropositivity were investigated.Results:The study included 253 children with a mean age of 16.7±6.23 years. The mean age at transplantation was 11.4±5.01 years. The seropositivity rates for vaccine-preventable viral infections varied: hepatitis B 89.7%, hepatitis A 60.5%, measles 78.7%, rubella 88.1%, mumps 61.2%, and varicella 71.9%. Cytomegalovirus seropositivity was 92.1% and Epstein-Barr virus seropositivity was 82.2%. Hepatitis B antibody positivity was 91.8% in patients undergoing hemodialysis, 94.5% in patients undergoing peritoneal dialysis, and 84.9% in pre-emptive transplantation patients (p=0.037). The mean age at transplantation was higher in patients with seropositivity for both cytomegalovirus and Epstein-Barr virus compared with seronegative patients (p<0.001 for both). The mean age at transplantation and diagnosis of glomerular disease was found to be effective for varicella seropositivity in multivariate regression analysis (OR 0.860, 95% CI: 0.808–0.915, p<0.001 and OR 2.502, 95% CI: 1.321–4.739, p=0.005, respectively).Conclusion:It is important to screen patients with chronic kidney disease in terms of vaccine-preventable diseases to identify risky groups of patients and to immunize these patients before end-stage kidney disease develops.

Immunity to Vaccine-preventable Viral Infections in Australians Being Evaluated for Liver Transplantation.

Vaccine-preventable viral infections are associated with increased risk of morbidity and mortality in immunocompromised patients. Current guidelines recommend routine screening and vaccination of all patients before solid organ transplantation. We studied rates of immunity against vaccine-preventable viruses in liver transplantation (LT) recipients. We retrospectively studied consecutive adult patients who underwent first deceased donor LT at a single center between August 2008 and October 2017. Viruses studied were hepatitis A (HAV), hepatitis B (HBV), varicella zoster virus (VZV), measles, and mumps. Hepatitis B surface antibody (anti-HBs) <10 IU/mL in HBV surface antigen-negative patients and negative IgG to other viruses was regarded as absent immunity. Five hundred and fifty-five patients underwent LT (72.4% male; median age, 55.0 y). Percentages of patients who lacked immunity to vaccine-preventable infections were HAV (31.8%), HBV (63.8%), measles (1.4%), mumps (6.6%), and VZV (3.8%). Age was positively associated with immunity (from either past exposure or vaccination) against most viruses, including HAV, measles, mumps, and VZV (P < 0.05 for all). In contrast, older age was marginally associated with anti-HBs <10 IU/mL (P = 0.046). No significant changes in immunity rates were observed during the study period. A substantial number of patients undergoing LT are not immune to vaccine-preventable viruses at the time of assessment. This presents an opportunity for pre-LT vaccination and in particular younger patients may need to be targeted.

Seroprevalence of Measles, Mumps, and Rubella Antibodies in College Students in Mumbai, India.

Measles, Mumps, and Rubella (MMR) are vaccine preventable viral infections, which cause significant mortality and morbidity globally. Increased incidence rates of these infectious diseases are observed in young adults. Information on seroprevalence data on MMR in India is limited. The objective of this study was to determine the prevalence of IgG antibodies against MMR among young adults. This was a descriptive cross-sectional study involving 192 healthy college students from Maharshi Dayanand College, Mumbai. The project was approved by the Institutional Ethics Committee of Haffkine Institute. Between December 2012 and September 2013, blood samples were collected from individuals of age 18-23 years after obtaining written informed consent from them. The quantitative determination of IgG antibodies in serum specimens against MMR was determined using enzyme linked immunosorbent assay. Data on history of vaccination were also collected from participants. Among 192 healthy college students (age 18-23 years), MMR seroprevalence was 91%, 97%, and 88%, respectively. The overall seropositivity of MMR was 79%. The highest level of seronegativity was seen with regards to rubella-specific antibodies in 12% of cases. About 96% of the participants did not know about their vaccination history while none of the participants knew about their history of MMR infections. Despite unknown vaccination status, a majority of college students in our study were found seropositive for all three infections, which indicate natural boosting. However, the proportion of seronegativity for measles and rubella was relatively higher. Especially since the study population belonged to reproductive age group, there is a concern of congenital rubella syndrome in the offspring. Although a larger multicentric study is required to confirm the findings, the results indicate that a dose of measles-rubella (MR) vaccine should be offered to these college students.

Social Regulations Predispose People to Complete Vaccination for Vaccine-Preventable Diseases

Japan experienced measles outbreaks in both 2006 and 2007 mainly among university students. Improvement of vaccine coverage against vaccine-preventable viral infections is the prime task for preventing outbreaks of viral infections. To elucidate the promoting factors for complete vaccination against measles, rubella, mumps, and varicella-zoster viruses, we conducted a case-control study among single university students in Japan. Information on vaccinations and clinico-demographical factors were collected using a self-administered questionnaire and a photocopy of the Maternal and Child Health Handbook. Logistic regression analysis was performed to estimate odds ratios (ORs) and their 95% confidence intervals (CIs) for two-time vaccination against measles and rubella viruses as mandatory vaccinations and at least one-time vaccination against mumps and varicella-zoster viruses as optional vaccinations. A total of 1,370 (744 medical, 508 paramedical, and 118 pharmaceutical) students were invited to participate, 960 (70.1%) of whom were enrolled in the study. Students aged < 20 years had a greater propensity for measles and rubella vaccinations (OR 7.8 [95% CI, 5.1-11.8] and OR 6.1 [95% CI, 3.7-10.0], respectively) compared with those aged ≥ 20 years. Students with a history of living over-seas for 1 month or longer were more likely to complete vaccination for measles (OR 4.4 [95% CI, 1.4-13.5] compared with those without such history. This significantly high vaccination coverage was attributed to the measles-rubella catch-up campaign by the Japanese government and the immunization regulations by foreign countries. These findings suggest that social regulations would predispose people to complete vaccination.

Rubella IgG Antibody among Nigerian Pregnant Women without Vaccination History

Rubella is a vaccine-preventable viral infection, its aetiologic agent; rubella virus was identified as human teratogen capable of causing a spectrum of birth defects described as congenital rubella syndrome (CRS). Despite the availability of safe and effective vaccines, significant proportion of the population remains susceptible to rubella infection in developing countries. More significantly, such developing countries including Nigeria have not demonstrated adequate commitment to preventive vaccination; a panacea for intervention. Consequently, this study was designed to determine the prevalence of anti-rubella IgG among pregnant women to ascertain the proportion of susceptible population. A total of 273 consenting rubella vaccine naïve antenatal clinic attendees aged 15-42 years (Median age = 28 years) were randomly selected and their sera analyzed for qualitative and quantitative anti-rubella IgG detection. Overall, 244/273 (89.4%) pregnant women enrolled in this study had protective level (Titre = &gt;10 IU/mL) of anti-rubella IgG (Median Titre = 165 IU/mL; Range = &lt;10 - &gt;250 IU/mL), while, 29/273 (10.6%) of the study population lack protective antibody titre ( OD = &lt;10 IU/mL). Results confirm previous reports of exposure, infection, and continuous circulation of rubella virus in Nigeria. It emphasizes the need for improved and continuous surveillance for rubella and CRS cases, prompt vaccination of vulnerable populations, and evaluation of health policies to achieve immunization and ultimately ensure control/elimination of rubella virus in Nigeria and beyond.Keywords: Rubella, Pregnancy, Antibody, Congenital Rubella Syndrome, Nigeria

STUDY ON SEROPREVALENCE OF MUMPS - SPECIFIC IgG ANTIBODIES IN A HEALTHY POPULATION

SUMMARY Mumps is a vaccine preventable viral infection. Its typical clinical manifestations are characterized by pain and swelling of the salivary glands, fever, and fatigue. Often other organs are affected - testes in males after puberty (orchitis), ovaries in women (ooforitis), pancreas (pancreatitis), central nervous system (meningities). The use of specific immune prophylaxis led to a significant success in the fight against mumps, but there are still unresolved issues related to the immunological and epidemiological effectiveness of the vaccines. The disease continues to interest researchers today. The main issues being tackled are related to the conduct of virological, clinical and seroepidemiological studies in different countries. Objectives of the study is to determine the frequency distribution of mumps-specific IgG antibodies in healthy populations in the region of Pleven, Bulgaria. Methods: a cross-sectional sero - epidemiological representative population - based survey in the area was made. Enzyme immunoassay method was used for an indirect proof of mumps - specific IgG serum antibodies. 410 people were examined at an average age of 25 (1 to 84). Of these, 250 (61 %) were women and 160 (39 %) - men. Results: Of all test results, the negative were 72 (19 %), the borderline were 12 (3 %), the positive were 182 (44 %), and highly positive were 144 (35 %). The vaccination status showed that 242 (69 %) of all surveyed were immunized with a vaccine against mumps. According to the immunization schedule in Bulgaria, 132 (33 %) people were immunized with monovaccine during the years - 1 intake, 80 (20 %) with trivaccine - 1 intake, and 64 (16 %) - 2 doses. Conclusion: We believe that despite the specific immunprophylaxis carried out against mumps decades on end, the necessary level of protection leading to its elimination has not yet been reached.

Prevalence of rubella IgG antibodies among pregnant women in Zaria, Nigeria

Rubella is a vaccine-preventable viral infection which in pregnancy can lead to foetal wastage and congenital malformations. A rubella IgG serosurvey of 430 consenting pregnant women attending the antenatal clinic was conducted at the Ahmadu Bello University Teaching Hospital, Zaria between 1 May 2007 and 29 February 2008. Questionnaires were also used to assess their level of awareness and pregnancy outcomes noted. Of the 430 serum samples tested, 421 (97.9%) were positive and 9 (2.1%) were negative for rubella IgG antibody. Differences in sociodemographic factors were of little significance between the groups and awareness of the infection was low. This high prevalence suggests that a sustained viral circulation exists in children and infection occurs early in infancy hence a high level of immunity exists in pregnant women with low levels of complications. In the absence of mass vaccination, all seronegative women should be vaccinated after delivery.

Seroprevalence of common vaccine-preventable viral infections in HIV-positive adults

Guidelines recommend a proactive approach for offering vaccination to susceptible HIV-infected patients. The size of the HIV-positive population that remains susceptible to vaccine-preventable infections is largely unknown. The study determined serostatus and recalled infection and vaccination history for measles, mumps, rubella, varicella-zoster virus (VZV), hepatitis A, and hepatitis B among HIV-positive adults accessing routine care. The study recruited 200 consecutive patients with a median CD4 count of 461 (interquartile range 326, 641) cells/mm(3); 62.5% were on suppressive antiretroviral therapy. Patients underwent serological testing and completed a questionnaire about recalled infection and vaccination history. Seronegativity rates were 7.0% [95% confidence interval 3.9-11.5%] for measles, 12.0% [7.5-16.5%] for mumps, 5.0% [2.4-9.0%] for rubella, 1.5% [0.3-4.3%] for VZV, 19.5% [14.0-25.0%] for hepatitis A, and 22.5% [16.7-28.3%] for hepatitis B. For hepatitis B, seropositivity rates were 6.5% [3.5-10.9%] for surface antigen, 38.0% [31.3-44.7%] for anti-core antibody, and 33.0% [26.5-39.5%] for anti-surface antibody alone. While patients who recalled a history of infection were generally seropositive, up to 50.5% of patients were unsure of their vaccination history. A proportion of HIV-positive adults lack evidence of immunity against common, vaccine-preventable viral infections. Efforts are needed to improve knowledge and records of vaccination history.

Seroprevalence survey of measles, rubella, varicella, and mumps antibodies in health care workers and evaluation of a vaccination program in a tertiary care hospital in Japan

Vaccine-preventable viral infections in health care workers (HCWs) have been on the rise for the past 10 years in Japan. To reduce the viral infections and the burden of exposure follow-up surveys at a tertiary care hospital in Osaka, Japan, a seroprevalence survey was conducted, and free vaccinations for measles, rubella, varicella, and mumps were offered to newly hired HCWs (199 physicians and 72 nurses and nursing assistants) who had negative serologic results for antibodies against these viruses. Negative antibody titers were obtained from 7.4% of the newly hired HCWs for measles, 12.5% for rubella, 4.1% for varicella, and 15.9% for mumps. The vaccination program for HCWs improved the vaccine-preventable infection rates and resulted in fewer exposure follow-up surveys, fewer lost work days, and fewer HCWs requiring hospitalization for these viral infections compared with those counted for the previous year. These data indicate that all HCWs should be strongly recommended to be vaccinated against (or have documented immunity to) these viruses in Japan, as is the case in the United States. (Am J Infect Control 2003;31:157-62.)

A 5-year review of measles cases admitted into the emergency paediatric unit of a tertiary hospital in Sokoto, North-Western Nigeria

Background: Measles is a vaccine preventable viral infection which is still responsible for significantly high morbidity and mortality in Sub-Saharan Africa. Failure of routine immunization programs heralds a dismal outlook for this potentially eradicable viral infection. The objective of this study was to determine the hospital prevalence, vaccination status, pattern of complications, and outcome of children admitted with measles into the Department of Pediatrics of Usmanu Danfodiyo University Teaching Hospital, Sokoto, Nigeria. Materials and Methods: This was a 5-year retrospective study from January 1, 2011 to December 31, 2015. Case folders of children below 15 years who were admitted with measles were retrieved, relevant information extracted, and entered into a pro forma. Data was analyzed using SPSS version 22. Results: Total admissions were 6104, out of which 204 were due to measles (prevalence, 3.3%). The mean age was 27.4 ± 18.9 months (range 6–96 months). Those aged 1–5 years were 144 (70.6%). The male-to-female ratio was 1.3:1. Only 28 patients (13.7%) had measles vaccination. Observed complications included bronchopneumonia in 168 (82.4%), acute laryngotracheobronchitis in 24 (11.8%), febrile convulsion in 20 (9.8%), encephalitis in 17 (8.3%), ocular complications in 12 (5.9%), and suppurative otitis media in 6 (2.9%) patients. The presence of complications was related to age