Diphtheria, tetanus, poliomyelitis, yellow fever and hepatitis B seroprevalence among HIV1-infected migrants. Results from the ANRS VIHVO vaccine sub-study

The immune status of migrant populations in Europe and implications for vaccine-preventable disease control: a systematic review and meta-analysis

BACKGROUND

Ensuring vaccination coverage reaches established herd immunity thresholds (HITs) is the cornerstone of any vaccination programme. Diverse migrant populations in European countries have been associated with cases of vaccine-preventable diseases (VPDs) and outbreaks, yet it is not clear to what extent they are an under-immunized group.

METHODS

We did a systematic review and meta-analysis to synthesize peer-reviewed published primary research reporting data on the immune status of migrants in EU/EEA countries, the UK and Switzerland, calculating their pooled immunity coverage for measles, mumps, rubella and diphtheria using random-effects models. We searched on Web of Science, Embase, Global Health and MEDLINE (1 January 2000 to 10 June 2022), with no language restrictions. The protocol is registered with PROSPERO (CRD42018103666).

FINDINGS

Of 1103 abstracts screened, 62 met eligibility criteria, of which 39 were included in the meta-analysis. The meta-analysis included 75 089 migrants, predominantly from outside Europe. Pooled immunity coverage among migrant populations was well below the recommended HIT for diphtheria (n = 7, 57.4% [95% confidence interval (CI): 43.1-71.7%] I2 = 99% vs HIT 83-86%), measles (n = 21, 83.7% [95% CI: 79.2-88.2] I2 = 99% vs HIT 93-95%) and mumps (n = 8, 67.1% [95% CI: 50.6-83.6] I2 = 99% vs HIT 88-93%) and midway for rubella (n = 29, 85.6% [95% CI: 83.1-88.1%] I2 = 99% vs HIT 83-94%), with high heterogeneity across studies.

INTERPRETATION

Migrants in Europe are an under-immunized group for a range of important VPDs, with this study reinforcing the importance of engaging children, adolescents and adults in 'catch-up' vaccination initiatives on arrival for vaccines, doses and boosters they may have missed in their home countries. Co-designing strategies to strengthen catch-up vaccination across the life course in under-immunized groups is an important next step if we are to meet European and global targets for VPD elimination and control and ensure vaccine equity.

Durability of tetanus seroprotection in people living with HIV

OBJECTIVES

Estimate the durability of tetanus toxoid (TT) -specific seroprotection in a cohort of people living with HIV (PLWH).

DESIGN

Cross-sectional study.

METHODS

PLWH with a last date of TT booster available were identified. TT-specific IgG were detected using commercial ELISA kit. Durability of seroprotection was estimated using linear regression model and analyzed according to the country of birth. The impact of baseline parameters at the time of vaccination (CD4+ T cell count, viral load and ART) was also assessed.

RESULTS

One-hundred and three subjects were included. The median duration between last TT booster and sampling was 5.6 years (IQR 2.6-8.9). Using linear regression model, half-life of TT-specific antibody was estimated at 9.9 years (95% CI: 5.5-50) in the whole cohort. Half-life was reduced in subjects born outside Europe: 4.4 years (95% CI: 2.9-8.5). PLWH born outside Europe had lower CD4+ T cell count at the time of immunization and more frequently a CD4+ T cell count nadir<200 mm3 before vaccination.

CONCLUSIONS

PLWH born outside Europe have lower half-life of TT-specific antibody as compared to previous study performed in the general population. Possible causes include lower nadir or current CD4+ T cell count or under-immunization status in country of origin before migration. Longer interval of booster vaccination, as recommended in the general population, might not be appropriate in this subgroup of PLWH.

Immunogenicity and duration of protection after yellow fever vaccine in people living with human immunodeficiency virus: a systematic review

BACKGROUND

We lack the rationale on which to base the development of a yellow fever (YF) vaccination schedule for people living with human immunodeficiency virus (PLWHIV).

OBJECTIVES

To report on the current evidence regarding the seroconversion rate and the duration of humoral protection after YF vaccine, as well as the impact of revaccination in PLWHIV.

DATA SOURCES

MEDLINE, Google Scholar, LILACS and Cochrane CENTRAL were searched.

METHODS

We selected studies on PLWHIV of all ages (including perinatally HIV-infected patients) and all settings (YF endemic and non-endemic zones). Intervention investigated was vaccination against YF, at least once after the HIV diagnosis. The research questions were the seroconversion rate, duration of humoral immunity after YF vaccine and impact of revaccination in PLWHIV. Selected studies were assessed for quality using the Newcastle-Ottawa scale.

RESULTS

Ten, six and six studies were selected for the systematic review of each question, respectively. Only one study addressed the first question in perinatally HIV-infected children. The quality of the studies was assessed as Poor (n = 16), Fair (n = 2) or Good (n = 4). A meta-analysis demonstrated that 97.6% (95% CI 91.6%-100%) of the included population seroconverted. Between 1 and 10 years after YF vaccine, reported persistence of neutralizing antibodies was 72% (95% CI 53.6%-91%), and it was 62% (95% CI 45.4%-78.6%) more than 10 years after YF vaccine. No conclusions could be drawn on impact of revaccination because of the small number of patients.

CONCLUSIONS

The current evidence regarding seroconversion rate, duration of humoral protection after YF vaccine and impact of revaccination in PLWHIV is limited by the low number and quality of studies. Based on the presently available data, it is difficult to rationally develop yellow fever vaccination guidelines for PLWHIV.

Tetanus seroprotection in people living with HIV: Risk factors for seronegativity, evaluation of medical history and a rapid dipstick test

OBJECTIVES

Tetanus is a vaccine-preventable disease. Booster immunization is required in order to induce long-lived tetanus-toxoid (TT) specific antibody response. We investigated the prevalence and risk factors of TT seronegativity in a cohort of people living with HIV (PWH) in Belgium along with the respective performance of vaccine history and a rapid dipstick test (Tetanus Quick Stick ® or TQS) compared to ELISA testing.

METHODS

PWH were prospectively enrolled and answered a questionnaire. ELISA was performed on serum or plasma using a commercial kit. A TT antibody level ≥ 0.15 IU / mL was considered protective. The TQS test was performed on a limited number of subjects.

RESULTS

Three-hundred forty-four subjects were included. The prevalence of tetanus seroprotection was 84,9%. Median age was 46.7 and 68% were born outside Belgium. Antiretroviral therapy coverage was almost universal (98.5%). After multivariable analysis, two risk factors were independently associated with TT seronegativity: an education level equivalent or below than secondary school and being born outside Europe. Vaccine history was shown to be unreliable (sensitivity: 43.8%; specificity: 76.5%; positive predictive value: 91.4% and negative predictive value :19.3%). The correlation between vaccine history and tetanus seroprotection was low (kappa coefficient = 0.09). The TQS performances were good (sensitivity 86.4%, specificity 96.0%, positive predictive value 99.3%, negative predictive value 52.17%). The correlation between TQS and tetanus seroprotection was substantial (kappa coefficient = 0.61).

CONCLUSIONS

In this cohort of PWH with a high proportion of migrants, socio-demographic and educational factors were associated with TT seronegativity while HIV-related factors were not, indicating that vaccine information should be tailored to cultural and educational background. As vaccine history is not reliable, TQS could represent an efficient tool for screening of TT-seronegativity.

Maternal immunisation to improve the health of HIV-exposed infants

HIV-exposed but uninfected (HEU) infants are at an increased risk of many infectious diseases that can contribute to the high mortality seen among HEU children. Maternal immunisation could be a promising strategy to reduce infections in HEU infants. However, very little research has explored the effect of HIV on the immunogenicity and effectiveness of vaccines given during pregnancy. We review the available evidence on maternal immunisation among women living with HIV (WLWH) for all vaccines recommended, considered, or being investigated for routine or risk-based use during pregnancy. Of the 11 vaccines included, only three have been investigated in WLWH. Available evidence suggests that maternal HIV infection limits the immunogenicity of several vaccines, leaving HEU infants more susceptible to infection during their first few months of life. Whether maternal immunisation reduces the infectious morbidity and mortality associated with infectious diseases in HEU children remains unknown. We conclude the Review by identifying future research priorities.

Influence of geographic origin on AIDS and serious non-AIDS morbidity/mortality during cART among heterosexual HIV-infected men and women in France

BACKGROUND

The influence of geographic origin on the risk of severe illness and death on cART has not been explored in European countries.

METHOD

We studied antiretroviral-naïve heterosexual HIV-1-infected individuals enrolled in the FHDH-ANRS CO4 cohort in France who started cART between 2006 and 2011. Individuals originating from France (French natives), sub-Saharan Africa (SSA) and non-French West-Indies (NFW) were studied until 2012. Crude and adjusted rate ratios (aRR) of severe morbid events/deaths (AIDS-related and non-AIDS-related) were calculated using Poisson regression models stratified by sex, comparing each group of migrants to French natives.

RESULTS

Among 2334 eligible men, 1379 (59.1%) originated from France, 838 (35.9%) from SSA and 117 (5.0%) from NFW. SSA male migrants had a higher aRR for non-AIDS infections, particularly bacterial infections (aRR 1.56 (95% CI 1.07-2.29), p = 0.0477), than French natives. Among 2596 eligible women, 1347 (51.9%) originated from France, 1131 (43.6%) from SSA, and 118 (4.5%) from NFW. SSA and NFW female migrants had a higher aRR for non-AIDS infections, particularly non-bacterial infections (respectively, 2.04 (1.18-3.53) and 7.87 (2.54-24.4), p = 0.0010), than French natives. We observed no other significant differences related to geographic origin as concerns the aRRs for AIDS-related infections or malignancies, or for other non-AIDS events/deaths such as cardiovascular disease, neurological/psychiatric disorders, non-AIDS malignancies and iatrogenic disorders, in either gender.

CONCLUSION

Heterosexual migrants from SSA or NFW living in France have a higher risk of non-AIDS-defining infections than their French native counterparts. Special efforts are needed to prevent infectious diseases among HIV-infected migrants.

Immunization Strategies Targeting Newly Arrived Migrants in Non-EU Countries of the Mediterranean Basin and Black Sea

Background: The World Health Organization recommends that host countries ensure appropriate vaccinations to refugees, asylum seekers and migrants. However, information on vaccination strategies targeting migrants in host countries is limited. Methods: In 2015-2016 we carried out a survey among national experts from governmental bodies of 15 non-EU countries of the Mediterranean and Black Sea in order to document and share national vaccination strategies targeting newly arrived migrants. Results: Four countries reported having regulations/procedures supporting the immunization of migrants at national level, one at sub-national level and three only targeting specific population groups. Eight countries offer migrant children all the vaccinations included in their national immunization schedule; three provide only selected vaccinations, mainly measles and polio vaccines. Ten and eight countries also offer selected vaccinations to adolescents and adults respectively. Eight countries provide vaccinations at the community level; seven give priority vaccines in holding centres or at entry sites. Data on administered vaccines are recorded in immunization registries in nine countries. Conclusions: Although differing among countries, indications for immunizing migrants are in place in most of them. However, we cannot infer from our findings whether those strategies are currently functioning and whether barriers to their implementation are being faced. Further studies focusing on these aspects are needed to develop concrete and targeted recommendations for action. Since migrants are moving across countries, development of on-line registries and cooperation between countries could allow keeping track of administered vaccines in order to appropriately plan immunization series and avoid unnecessary vaccinations.

Vaccinations in migrants and refugees: a challenge for European health systems. A systematic review of current scientific evidence

The decline of immunization rates in countries of origin of migrants and refugees, along with risky conditions during the journey to Europe, may threaten migrants' health. We performed a systematic review of the scientific literature in order to assess the frequency of vaccine preventable diseases, and vaccination coverage among migrants and refugees in Europe. To this end, Medline and Cochrane databases were considered. After the screening and the selection process, 58 papers were included in the review. We focused on the following vaccine-preventable diseases: hepatitis B, measles, rubella, mumps, tetanus, poliomyelitis, pertussis, diphtheria, meningitis, and varicella. The results were presented as a qualitative synthesis. In summary, several studies highlighted that migrants and refugees have lower immunization rates compared to European-born individuals. Firstly, this is due to low vaccination coverage in the country of origin. Then, several problems may limit migrants' access to vaccination in Europe: (i) migrants are used to move around the continent, and many vaccines require multiple doses at regular times; (ii) information on the immunization status of migrants is often lacking; (iii) hosting countries face severe economic crises; (iv) migrants often refuse registration with medical authorities for fear of legal consequences and (v) the lack of coordination among public health authorities of neighboring countries may determine either duplications or lack of vaccine administration. Possible strategies to overcome these problems include tailoring immunization services on the specific needs of the target population, developing strong communication campaigns, developing vaccination registers, and promoting collaboration among public health authorities of European Countries.

Immunization of HIV-infected adult patients - French recommendations

Human immunodeficiency virus (HIV)-infected patients remain at increased risk of infection including vaccine-preventable diseases. Vaccines are therefore critical components in the protection of HIV-infected patients from an increasing number of preventable diseases. However, missed opportunities for vaccination among HIV-infected patients persist and vaccine coverage in this population could be improved. This article presents the French recommendations regarding immunization of HIV-infected adults in the light of the evidence-based literature on the benefits and the potential risks of vaccines among this vulnerable population.

Vaccination status of people living with HIV/AIDS in outpatient care in Fortaleza, Ceará, Brazil

Antiretroviral therapy has increased the survival of patients with HIV/AIDS, thus necessitating health promotion practice with immunization. Vaccines are critical components for protecting people living with HIV/AIDS (PLWHA). The purpose of study was to analyze the vaccination status of PLWHA in outpatient care in Fortaleza, Ceará, Brazil. Cross-sectional study performed from June 2014 to June 2015. The screening was done with patients in antiretroviral therapy, 420 patients underwent screening, but only 99 met the inclusion criteria. Data were collected for interviews using forms to characterize sociodemographic, clinical and vaccination situations. Only 14 patients had complete vaccination schedules. The most used vaccines were hepatitis B, influenza vaccine and 23-valent pneumococcal. There was no difference between men and women regarding the proportion of PLWHA with full vaccination schedule or between sex, skin color, marital status, sexual orientation, religion or occupational status. There was no difference between having or not having a complete vaccination schedule and age, years of education, family income or number of hospitalizations. CD4+ T-cells count of patients with incomplete immunization was lower than patients with complete immunization. Health education strategies can be done individually or in groups to explain the importance of vaccination and to remind about doses to be administered. Most patients did not have proper adherence to vaccination schedules, especially due to lack of guidance. Results implied that education in health is important for vaccination adhesion, knowledge of adverse events and continuation of schemes.