Presumptive Vaccination Research Articles

Assessment of the Clinical and Economic Impact of Different Immunization Protocols of Measles, Mumps, Rubella and Varicella in Internationally Adopted Children.

The appropriate immunization of internationally adopted children (IAC) is currently under debate and different approaches have been suggested. The aim of this study is to evaluate the clinical and economic impact of different strategies of measles, mumps, rubella, and varicella (MMRV) immunization in IAC in Italy. A decision analysis model was developed to compare three strategies: presumptive immunization, pre-vaccination serotesting and vaccination based on documentation of previous immunization. Main outcomes were the cost of strategy, number of protected IAC, and cost per child protected against MMRV. Moreover, the incremental cost-effectiveness ratio (ICER) was calculated. The strategy currently recommended in Italy (immunize based on documentation) is less expensive. On the other hand, the pre-vaccination serotesting strategy against MMRV together, improves outcomes with a minimum cost increase, compared with the presumptive immunization strategy and compared with the comparator strategy. From a cost-effectiveness point of view, vaccination based on serotesting results in being the most advantageous strategy compared to presumptive vaccination. By applying a chemiluminescent immunoassay test, the serology strategy resulted to be clinically and economically advantageous. Similar results were obtained excluding children aged <1 year for both serology methods. In conclusion, based on our analyses, considering MMRV vaccine, serotesting strategy appears to be the preferred option in IAC.

Interventions to Improve Vaccination Uptake and Cost Effectiveness of Vaccination Strategies in Newly Arrived Migrants in the EU/EEA: A Systematic Review.

Newly arrived migrants to the EU/EEA (arrival within the past five years), as well as other migrant groups in the region, might be under-immunised and lack documentation of previous vaccinations, putting them at increased risk of vaccine-preventable diseases circulating in Europe. We therefore performed a systematic review conforming to PRISMA guidelines (PROSPERO CRD42016045798) to explore: (i) interventions that improve vaccine uptake among migrants; and (ii) cost-effectiveness of vaccination strategies among this population. We searched MEDLINE, Embase, CINAHL, and Cochrane Database of Systematic Reviews (CDSR) between 1 January 2006 to 18 June 2018. We included three primary intervention studies performed in the EU/EEA or high-income countries and one cost effectiveness study relevant to vaccinations in migrants. Intervention studies showed small but promising impact only on vaccine uptake with social mobilization/community outreach, planned vaccination programs and education campaigns. Targeting migrants for catch-up vaccination is cost effective for presumptive vaccination for diphtheria, tetanus, and polio, and there was no evidence of benefit of carrying out pre-vaccination serological testing. The cost-effectiveness is sensitive to the seroprevalence and adherence to vaccinations of the migrant. We conclude that scarce but direct EU/EEA data suggest social mobilization, vaccine programs, and education campaigns are promising strategies for migrants, but more research is needed. Research should also study cost effectiveness of strategies. Vaccination of migrants should continue to be a public heath priority in EU/EEA.

Seroepidemiology of varicella‐zoster virus and reliability of varicella history in Turkish children, adolescents and adults

This study aimed to assess the age specific varicella-zoster virus (VZV) seroprevalence in Izmir, Turkey and to determine the reliability of a history of varicella to detect susceptible children, adolescents and adults. A questionnaire, including previous history of varicella, was completed for each participant and, in 590 of them, VZV-specific IgG was measured using an ELISA test. Overall, 28.5% of individuals were seronegative for VZV. By 5 years of age, only 25.5% of children were seropositive for VZV. Among adolescents and young adults, 18.8% and 11.7% were seronegative, respectively. The negative predictive value was 57.8%, decreasing with age (81.9% in children, 34.5% in adolescents and 8.3% in adults). In conclusion, a negative history of varicella is not a reliable predictor of varicella antibody status in adolescents and young adults. Serological testing before immunisation will be logical, rather than presumptive vaccination, for adolescents and adults with negative history of varicella.

Presumptive varicella vaccination is warranted in Greek adolescents lacking a history of disease or household exposure

Current practice favors serotesting adolescents with a negative history of chickenpox rather than offering presumptive vaccination. Recent epidemiologic data from Greece indicate that a high proportion of adolescents (21.5%) are susceptible to chickenpox. We assessed the reliability of negative varicella history in relation to type of exposure in 311 children and 283 adolescents. In children with social or unknown exposure to varicella, a negative history had a high negative predictive value (NPV = 73.5), supporting the clinical practice of presumptive vaccination. Conversely, children with a negative history and household exposure had a low NPV (13.8), suggesting that pre-vaccination serologic testing is warranted. In conclusion, based on our local epidemiologic data, presumptive varicella vaccination should be offered to all adolescents with the exception of the subgroup of adolescents with household exposure.

Economic Analysis of Prevaccination Serotesting Compared With Presumptive Immunization for Polio, Diphtheria, and Tetanus in Internationally Adopted and Immigrant Infants

No consensus exists about whether to conduct prevaccination serotesting or to presumptively vaccinate internationally adopted and immigrant infants with inactivated polio (IPV) and diphtheria-tetanus-acellular pertussis (DTaP) immunizations. To study the clinical and economic outcomes from a societal perspective of prevaccination serotesting in a hypothetical 12-month-old internationally adopted or immigrant infant. A decision analysis model was developed comparing presumptive vaccination with IPV versus serotesting for poliovirus type 1, 2, and 3 antibodies followed by vaccination in unprotected patients. A similar decision analysis model was developed comparing presumptive vaccination with DTaP versus serotesting for diphtheria and tetanus toxoid antibodies. The main outcome measures were cost per patient protected from polio, diphtheria, and tetanus. Compared with presumptive immunization, prevaccination serotesting for polio increases the cost per patient from $57 to $62 and decreases the percentage of patients protected against polio from 95.3% to 94.0%. Serotesting for diphtheria and tetanus increases the cost per patient from $62 to $119 and increases the percentage of patients protected against both diphtheria and tetanus from 91.5% to 92.3%. Presumptive immunization with DTaP costs less and is more clinically effective than serotesting if >80% of patients do not complete the full vaccine series or if antibody seroprevalence to both diphtheria and tetanus is <51%. Presumptive immunization for polio improves outcomes and saves costs compared with prevaccination serotesting in internationally adopted and immigrant infants. The results for DTaP are less definitive, although immunization is the preferred strategy in populations with poor vaccine compliance or low seroprevalence of antibodies to diphtheria and tetanus.

Review of the Cost Effectiveness of Immunisation Strategies for the Control of Epidemic Meningococcal Meningitis

Outbreaks of meningococcal disease have caused devastation worldwide. Effective vaccines have not been used routinely, due to perceived limitations of the duration of effectiveness as well as immunogenicity when administered during infancy. Given the sporadic nature of outbreaks, the optimal use of these vaccines to control both short-term epidemic and endemic meningococcal disease has been the subject of much debate. Seven economic studies on the use of polysaccharide vaccination strategies help to highlight the relevant epidemiological and economic issues surrounding the decisions for their use. Five of these studies were based in Africa, the region where annual incidence rates can be several orders of magnitude greater than the rest of the world. These studies demonstrated that vaccination against meningococcal disease during outbreak situations is suboptimal given the inability to rapidly immunise populations in a timely fashion in resource-poor areas. However, depending on the disease incidence and the ability to deliver vaccines, the polysaccharide vaccine can be cost effective for preventive strategies when given prior to the start of outbreaks, either through presumptive vaccination or through a modified routine delivery strategy. Economic analyses of mass immunisation campaigns and modelled routine vaccination suggest that routine use of meningococcal vaccines for preventive strategies could be within the range of cost-effective public health interventions in those regions of the world where meningococcal disease is endemic. This includes the meningococcal belt of Africa, the Sahelian region.

Varicella serology among school age children with a negative or uncertain history of chickenpox.

Clinicians who offer varicella vaccination to school age children face the dilemma of whether to serotest or vaccinate presumptively. Varicella seroprevalence among 7- to 12-year-old children with negative or uncertain histories has not previously been studied. Our main objective was to describe varicella seroprevalence among children ages 7 to 12 years with a negative or uncertain history of chickenpox. This was a cross-sectional study of children whose clinicians had ordered varicella serotesting. Guidelines from the medical group's regional pediatric infectious disease specialists recommended obtaining varicella serology on all children 7 to 12 years old with a negative or uncertain history. Parents were interviewed by telephone about the child's history of chickenpox before test results were completed. Varicella seroprevalence ranged from 9% among 7-year-olds whose parents said they had definitely not had chickenpox to 68% among 11-year-olds whose parents were not sure whether they had had chickenpox. Among children whose parents were uncertain about their chickenpox history, almost one-half (48%) were seropositive. Twenty-five percent of children whose parents said they definitely had not and 32% of children whose parents said they had probably not had chickenpox were seropositive. Of parents whose children had experienced serotesting, 73% said they would prefer to have the blood test first rather than presumptive vaccination. For a large health maintenance organization, it was projected to be most cost-effective (in terms of cost per chickenpox case prevented) to recommend testing for children 9 to 12 years old with uncertain histories of chickenpox. We conclude that among children 7 to 12 years old with negative or uncertain histories of chickenpox, varicella seroprevalence ranges from 9 to 68% depending on age and clinical history. Parents are generally receptive to serotesting, although individual preferences vary. In the population we studied it would be most cost-effective to recommend testing before deciding about vaccination for children 9 to 12 years old with uncertain histories of chickenpox.