Immune response to co-administration of measles, mumps, and rubella (MMR), and yellow fever vaccines: a randomized non-inferiority trial among one-year-old children in Argentina.

BACKGROUND: In yellow fever (YF) endemic areas, measles, mumps, and rubella (MMR), and YF vaccines are often co-administered in childhood vaccination schedules. Because these are live vaccines, we assessed potential immune interference that could result from co-administration. METHODS: We conducted an open-label, randomized non-inferiority trial among healthy 1-year-olds in Misiones Province, Argentina. Children were randomized to one of three groups (1:1:1): Co-administration of MMR and YF vaccines (MMR1YF1), MMR followed by YF vaccine four weeks later (MMR1YF2), or YF followed by MMR vaccine four weeks later (YF1MMR2). Blood samples obtained pre-vaccination and 28 days post-vaccination were tested for immunoglobulin G antibodies against measles, mumps, and rubella, and for YF virus-specific neutralizing antibodies. Non-inferiority in seroconversion was assessed using a -5% non-inferiority margin. Antibody concentrations were compared with Kruskal-Wallis tests. RESULTS: Of 851 randomized children, 738 were correctly vaccinated, had ≥ 1 follow-up sample, and were included in the intention-to-treat population. Non-inferior seroconversion was observed for all antigens (measles seroconversion: 97.9% in the MMR1YF1 group versus 96.3% in the MMR1YF2 group, a difference of 1.6% [90% CI -1.5, 4.7]; rubella: 97.9% MMR1YF1 versus 94.7% MMR1YF2, a difference of 3.3% [-0.1, 6.7]; mumps: 96.7% MMR1YF1 versus 97.9% MMR1YF2, a difference of -1.3% [-4.1, 1.5]; and YF: 96.3% MMR1YF1 versus 97.5% YF1MMR2, a difference of -1.2% [-4.2, 1.7]). Rubella antibody concentrations and YF titers were significantly lower following co-administration; measles and mumps concentrations were not impacted. CONCLUSION: Effective seroconversion was achieved and was not impacted by the co-administration, although antibody levels for two antigens were lower. The impact of lower antibody levels needs to be weighed against missed opportunities for vaccination to determine optimal timing for MMR and YF vaccine administration. TRIAL REGISTRATION: The study was retrospectively registered in ClinicalTrials.gov (NCT03368495) on 11/12/2017.

Use of alternative care sites during the COVID-19 pandemic in the city of Buenos Aires, Argentina.

OBJECTIVES: In large cities, where a large proportion of the population live in poverty and overcrowding, orders to stay home to comply with isolation requirements are difficult to fulfil. In this article, the use of alternative care sites (ACSs) for the isolation of patients with confirmed COVID-19 or persons under investigation (PUI) in the City of Buenos Aires during the first wave of COVID-19 are described. STUDY DESIGN: This is a cross-sectional study. METHODS: All patients with COVID-19 and PUI with insufficient housing resources who could not comply with orders to stay home and who were considered at low clinical risk in the initial triage were referred to refurbished hotels in the City of Buenos Aires (Ciudad Autónoma de Buenos Aires [CABA]). ACSs were divided into those for confirmed COVID-19 patients and those for PUI. RESULTS: From March to August 2020, there were 58,143 reported cases of COVID-19 (13,829 of whom lived in slums) in the CABA. For COVID-19 positive cases, 62.1% (n = 8587) of those living in slums and 21.4% (n = 9498) of those living outside the slums were housed in an ACS. In total, 31.1% (n = 18,085) of confirmed COVID-19 cases were housed in ACSs. In addition, 7728 PUI were housed (3178 from the slums) in an ACS. The average length of stay was 9.0 ± 2.5 days for patients with COVID-19 and 1.6 ± 0.7 days for PUI. For the individuals who were housed in an ACS, 1314 (5.1%) had to be hospitalised, 56 were in critical care units (0.22%) and there were 27 deaths (0.1%), none during their stay in an ACS. CONCLUSIONS: Overall, about one-third of all people with COVID-19 were referred to an ACS in the CABA. For slum dwellers, the proportion was >60%. The need for hospitalisation was low and severe clinical events were rare. This strategy reduced the pressure on hospitals so their efforts could be directed to patients with moderate-to-severe disease.

Final assessment of the COVID-19 pandemic impact between the different social and economic strata population of the city of Buenos Aires.

Background: During the pandemic, epidemiological communications reported an estimation of excess deaths. However, the final calculation requires a detailed analysis. The study aim was to ascertain the number and distribution of COVID-19 fatalities among various socio-economic strata in a large, moderate to low-income city. Study design: Observational time series analysis in a large city, treated as a natural experiment. Methods: Analysis of death certificates, demographic data, and health system records of positive RT-PCR COVID-19 tests from 2015 to 2021, categorizing by age, sex, and place of residence. The study measured the pandemic's impact on mortality, including COVID and non-COVID deaths, using corrected Poisson regression models for different demographics and assessing socio-economic status impact via ecological community-level analysis. Results: Compared to the pre-pandemic period (2015-2019, IRR = 1.00), the sex- and age-adjusted rate of all-cause death increased significantly during the pandemic (2020-2021) IRR = 1.109 [1.054-1.167], p < 0.0001. This was observed in both males (IRR = 1.158 [1.1-1.219], p < 0.0001) and females (IRR = 1.068 [1.016-1.124], p = 0.01). There was no observed effect of the pandemic on the historical trend in the progressive reduction of mortality in people under 35 years of age. The increase in deaths was at the expense of COVID (+11,175 deaths) and cardiovascular causes (IRR = 1.114 [1.020-1.217] p = 0.017). During the pandemic, there was a significant increase in deaths at home (IRR = 1.219 [1197-1.242], p < 0.0001), especially in people dying of cardiovascular causes (IRR = 1.391 [1.360-1.422], p < 0.0001). The increase in the adjusted mortality rate during the pandemic was socially conditioned. Conclusions: The pandemic not only led to increased COVID-19 mortality but also heightened fatalities from non-COVID causes, reflecting a potential bias in healthcare resource allocation towards SARS-CoV-2 at the expense of chronic pathologies care.

Immunogenicity induced by the use of alternative vaccine platforms to deal with vaccine shortages in a low- to middle-income country: Results of two randomized clinical trials.

BACKGROUND: Shortages of component two of Sputnik V vaccine (rAd5) are delaying the possibility of achieving full immunisation. The immunogenic response associated with the use of alternative schemes to complete the scheme was not explored. METHODS: We did two non-inferiority randomized clinical trials with outcomes measures blinded to investigators on adults aged 21-65 years, vaccinated with a single dose of rAd26 ≥ 30 days before screening and no history of SARS-CoV-2. Participants were assigned (1:1:1:1:1) to receive either rAd5; ChAdOx1; rAd26; mRNA-1273 or BBIBP-CorV. The primary endpoint was the geometric mean ratio (GMR) of SARS-CoV-2 anti-spike IgG concentration at 28 days after the second dose, when comparing rAd26/rAd5 with rAd26/ChAdOx1, rAd26/rAd26, rAd26/mRNAmRNA-1273 and rAd26/BBIBP-CorV. Serum neutralizing capacity was evaluated using wild type SARS-CoV-2 reference strain 2019 B.1. The safety outcome was 28-day rate of serious adverse. The primary analysis included all participants who received ≥ 1 dose. The studies were registered with NCT04962906 and NCT05027672. Both trials were conducted in Buenos Aires, Argentina. FINDINGS: Between July 6 and August 3, 2021, 540 individuals (age 56·7 [SD 7·3]; 243 (45%) women) were randomly assigned to received rAd5 (n=150); ChAdOx1 (n=150); rAd26 (N=87); mRNAmRNA-1273 (n=87) or BBIBP-CorV (n=65). 524 participants completed the study. As compared with rAd26/rAd5 (1·00), the GMR (95%CI) at day 28 was 0·65 (0·51-0·84) among those who received ChAdOx1; 0·47 (0·34-0·66) in rAd5; 3·53 (2·68-4·65) in mRNA-1273 and 0·23 (0·16-0·33) in BBIBP-CorV. The geometric mean (IU/ml) from baseline to day 28 within each group increased significantly with ChAdOx1 (4·08 (3·07-5·43)); rAd26 (2·69 (1·76-4·11)); mRNA-1273 (21·98 (15·45-31·08)) but not in BBIBP-CorV (1·22 (0·80-1·87)). INTERPRETATION: Except for mRNA-1273 which proved superior, in all other alternatives non-inferiority was rejected. Antibody concentration increased in all non-replicating viral vector and RNA platforms. FUNDING: The trials were supported (including funding, material support in the form of vaccines and testing supplies) by the Buenos Aires City Government.

Evaluation of a COVID-19 Vaccine Campaign and SARS-CoV-2 Infection and Mortality Among Adults Aged 60 Years And Older in a Middle-Income Country.

Importance: Although there are reports of COVID-19 vaccine implementation in real-world populations, these come from high-income countries or from experience with messenger RNA technology vaccines. Data on outcomes of vaccine deployment in low- or middle-income countries are lacking. Objective: To assess whether the pragmatic application of the 3 COVID-19 vaccines available in Argentina, 2 of which have no reports of evaluation in real-world settings to date, were associated with a reduction in morbidity, all-cause mortality, and mortality due to COVID-19. Design, Setting, and Participants: This cohort study used individual and ecological data to explore outcomes following vaccination with rAd26-rAd5, ChAdOx1, and BBIBP-CorV. To correct for differences in exposure times, results are shown using incidence density per 100 000 person-days from the start of the vaccination campaign (December 29, 2020) to the occurrence of an event or the end of follow-up (May 15, 2021). Participants included 663 602 people aged at least 60 years residing in the city of Buenos Aires, Argentina. Statistical analysis was performed from June 1 to June 15, 2021. Main Outcomes and Measures: Diagnosis of COVID-19 confirmed by reverse transcription-polymerase chain reaction, death from all causes, and death within 30 days of a diagnosis of COVID-19. Poisson regression models were fitted to estimate associations with all 3 outcomes. Results: Among 663 602 residents of the city of Buenos Aires included in the study, 540 792 (81.4%) were vaccinated with at least 1 dose, with 457 066 receiving 1 dose (mean [SD] age, 74.5 (8.9) years; 61.5% were female [n = 281 284]; 68.0% [n = 310 987] received the rAd26-rAd5 vaccine; 29.5% [n = 135 036] received ChAdOx1; 2.4% [n = 11 043] received BBIBP-CorV) and 83 726 receiving 2 doses (mean [SD] age, 73.4 [6.8] years; 63.5% were female [n = 53 204]). The incidence density of confirmed COVID-19 was 36.25 cases/100 000 person-days (95% CI, 35.80-36.70 cases/100 000 person-days) among those who did not receive a vaccine, 19.13 cases/100 000 person-days (95% CI, 18.63-19.62 cases/100 000 person-days) among those who received 1 dose, and 4.33 cases/100 000 person-days (95% CI, 3.85-4.81 cases/100 000 person-days) among those who received 2 doses. All-cause mortality was 11.74 cases/100 000 person-days (95% CI, 11.51-11.96 cases/100 000 person-days), 4.01 cases/100 000 person-days (95% CI, 3.78-4.24 cases/100 000 person-days) and 0.40 cases/100 000 person-days (95% CI, 0.26-0.55 cases/100 000 person-days). COVID-19-related-death rate was 2.31 cases/100 000 person-days (95% CI, 2.19-2.42 cases/100 000 person-days), 0.59 cases/100 000 person-days (95% CI, 0.50-0.67 cases/100 000 person-days), and 0.04 cases/100 000 person-days (95% CI, 0.0-0.09 cases/100 000 person-days) among the same groups. A 2-dose vaccination schedule was associated with an 88.1% (95% CI, 86.8%-89.2%) reduction in documented infection, 96.6% (95% CI, 95.3%-97.5%) reduction in all-cause death, and 98.3% (95% CI, 95.3%-99.4%) reduction in COVID-19-related death. A single dose was associated with a 47.2% (95% CI, 44.2%-50.1%) reduction in documented infection, 65.8% (95% CI, 61.7%-69.5%) reduction in all-cause death, and 74.5% (95% CI, 66%-80.8%) reduction in COVID-19-related death. Conclusions and Relevance: This study found that within the first 5 months after the start of the vaccination campaign, vaccination was associated with a significant reduction in COVID-19 infection as well as a reduction in mortality.

The role of National Immunization Technical Advisory Groups (NITAG) in strengthening health system governance: Lessons from three middle-income countries-Argentina, Jordan, and South Africa (2017-2018).

INTRODUCTION: Toward the Global Vaccine Action Plan 2020 goal, almost 90% of countries have established a National Immunization Technical Advisory Group (NITAG). However, little is known about NITAG's contributions to governance. METHODS: In 2017-2018, a two-step, qualitative retrospective study was conducted. Jordan (JO), Argentina (AR), and South Africa (SA) were selected owing to government-financed NITAGs from middle-income countries (MICs), geographic diversity, and a vaccine introduction with NITAG support. Country case studies were developed, collecting data through desk review and face-to-face key informant interviews (KIIs) from Ministry of Health (MoH) and NITAG. Case studies were analyzed together, to assess governance applying the European Observatory on Health Systems and Policies framework focusing on transparency, accountability, participation, integrity, and policy capacity (TAPIC). RESULTS: Document review and 53 KII (22 AR, 20 SA, 11 JO) showed NITAGs played a pivotal role as advisors promoting a culture of evidence-informed policies. NITAGs strengthened governance, although practices varied among countries. Meetings were conducted behind-closed-doors, participation restricted to members, only in one country agendas, and recommendations were public (AR). To increase participation, policy capacity, and transparency, countries considered adding experts in communications, advocacy, and economics. AR and SA contemplated including community members. NITAGs functioned autonomously from the government, with no established internal or external monitoring or supervision. NITAG meeting minutes allowed the review of integrity, adherence to terms of reference, standard operating procedures, and conflict of interest (CoI). For the most part, NITAGs abided by their mandates. Significant issues were related to the level of MoH support and oversight of CoI declaration and documentation. CONCLUSIONS: Systematically implementing governance approaches could improve processes, better tailor policies, and implementation. The long-term survival and resilience of NITAGs in these countries showed they play a significant role in strengthening governance. Lessons learned could be useful to those promoting country-driven evidence-informed decision-making.

Viruela símica: zoonosis emergente con impacto global / Monkeypox: emerging zoonosis with unprecedentedglobal impact

El virus de la viruela símica es un orthopoxvirus de características zoonóticas endémico en las regiones de África Central y África Occidental, donde causa brotes desde 1970. En las últimas décadas se registró un aumento exponencial de casos, probablemente asociado a la disminución en la inmunidad conferida por la vacuna antivariólica, discontinuada luego de la erradicación de la viruela. En los últimos años se registraron casos esporádicos fuera del continente africano, siempre relacionados epidemiológicamente a la permanencia en áreas endémicas o contacto con animales infectados. Desde el 13 de mayo de 2022 se encuentra en curso el mayor brote de viruela símica registrado fuera de las áreas endémicas de África, con casos en los cinco continentes. La extensión, el impacto y la duración del brote permanecen aún inciertos.

Monkeypox virus is an orthopoxvirus with zoonotic characteristics endemic in Central and West Africa regions, where it has caused outbreaks since 1970. An exponential increase in cases has been registered in the last decades, probably associated with a decrease in the immunity conferred by the smallpox vaccine, discontinued after smallpox eradication. In recent years, sporadic cases have been reported outside the African continent, always epidemiologically related to permanence in endemic areas or contact with infected animals. Since May 13, 2022, the largest monkeypox outbreak ever reported outside Africa endemic areas, with cases on the five continents, is unfolding. The extent, impact and duration of this outbreak still remain uncertain

National Immunization Commission: strengthening evidence-based decision making in Argentina.

In Argentina, the National Technical Advisory Group on Immunizations is represented by the National Immunization Commission (CoNaIn), an organization created by the Ministry of Health in 2000. Recently, the Argentine government has decided to prioritize vaccination as a state policy, emphasizing this strategy as a sign of social equity so CoNaIn was restructured to increase its capacity to formulate sound and evidence-based recommendations. The commission shall consist of a group of immunization experts, representatives of scientific societies, the immunization program and the Ministry of Health. Its functions include the formulation of recommendations on the introduction of vaccines into the immunization program. The recommendations are based on technical, programmatic and social criteria. This decision-making process transparent with the support and advice of experts and scientific societies and guided by available evidence decisions help strengthen the Ministry of Health immunization policy generating greater confidence and support from the population and health professionals.

Yellow fever vaccine-associated adverse events following extensive immunization in Argentina.

As a consequence of YF outbreaks that hit Brazil, Argentina, and Paraguay in 2008-2009, a significant demand for YF vaccination was subsequently observed in Argentina, a country where the usual vaccine recommendations are restricted to provinces that border Brazil, Paraguay, and Bolivia. The goal of this paper is to describe the adverse events following immunization (AEFI) against YF in Argentina during the outbreak in the northeastern province of Misiones, which occurred from January 2008 to January 2009. During this time, a total of nine cases were reported, almost two million doses of vaccine were administered, and a total of 165 AEFI were reported from different provinces. Case study analyses were performed using two AEFI classifications. Forty-nine events were classified as related to the YF vaccine (24 serious and 1 fatal case), and 12 events were classified as inconclusive. As the use of the YF 17D vaccine can be a challenge to health systems of countries with different endemicity patterns, a careful clinical and epidemiological evaluation should be performed before its prescription to minimize serious adverse events.

El viajero con VIH/Sida / The traveler living with AIDS

Las personas que conviven con el VIH en la actualidad pueden viajar más debido a los evidentes beneficios del tratamiento antirretroviral. Estos viajeros tienen especiales requerimientos en cuanto a las medidas preventivas y pueden tener limitaciones o veda para el ingreso a determinados países...

Vacuna antirrábica de uso humano / Human rabies vaccine

La rabia es una zoonosis viral que puede afectar todo tipo de mamíferos. Los reservorios primarios, sin embargo, pertenecen a los órdenes Carnivora (Subórdenes: Caniformia ûcánidos- y Feliformia ûfelinos-) y Chiroptera (murciélagos). El perro doméstico (Canis familiaris) es la especie más significativa en cuanto a la transmisión del virus al ser humano y como tal es responsable de millones de exposiciones y decenas de miles de muertes humanas por año en todo el mundo. La encefalitis por rabia, de curso fatal, se presenta cuando una persona tiene un accidente con un animal transmisor y no se adoptan las medidas profilácticas adecuadas para prevenirla, que incluyen un adecuado cuidado de la herida, más el uso de vacuna y -cuando es necesario- gammaglobulina específica. En 2008 se registró, después de 14 años sin denuncias, un caso de rabia humana transmitida por perro en un niño de la Provincia de Jujuy. La lista de los últimos años de nuestro país se completa con otro de transmisión canina (Tucumán, en 1994) y dos más, ambos consecutivos a mordeduras de quirópteros (Chaco, en 1997 y Corrientes, en 2001).