Immunogenicity and reactogenicity of heterologous immunization against SARS CoV-2 using Sputnik V, ChAdOx1-S, BBIBP-CorV, Ad5-nCoV, and mRNA-1273.

Heterologous vaccination against coronavirus disease 2019 (COVID-19) provides a rational strategy to rapidly increase vaccination coverage in many regions of the world. Although data regarding messenger RNA (mRNA) and ChAdOx1 vaccine combinations are available, there is limited information about the combination of these platforms with other vaccines widely used in developing countries, such as BBIBP-CorV and Sputnik V. Here, we assess the immunogenicity and reactogenicity of 15 vaccine combinations in 1,314 participants. We evaluate immunoglobulin G (IgG) anti-spike response and virus neutralizing titers and observe that a number of heterologous vaccine combinations are equivalent or superior to homologous schemes. For all cohorts in this study, the highest antibody response is induced by mRNA-1273 as the second dose. No serious adverse events are detected in any of the schedules analyzed. Our observations provide rational support for the use of different vaccine combinations to achieve wide vaccine coverage in the shortest possible time.

Hepatitis A outbreak affecting men who have sex with men (MSM) in central Argentina, occurred in July 2017-April 2018, later than the European outbreak.

BACKGROUND: During June-2016-May-2017, several outbreaks of HA were recorded in Europe, especially described in MSM. In our area since July-2017, an increase of hepatitis A (HA) notification was reported. OBJECTIVE: In order to understand the unusual increase of cases occurred in the central region of Argentina, the aim of this study was to describe, characterize and contextualize epidemiologically the HA outbreak occurred this area, until April2018. STUDY DESIGN: HA cases (positive anti-HAV IgM) obtained from the calendar week 29/2017 in which the first case of MSM was recognized were included in our study. HAV RNA detection and molecular characterization was performed from serum samples and/or stool by RT - PCR of VP1/2A genomic region (360bp). RESULTS: Of the 32 cases notified, 87.5% of them were unvaccinated men and 69.6% were MSM (mean age 31.9 years). All MSM associated HAV sequences were genotyped as IA, and clustered with the VRD 521-2016 strain, responsible of causing outbreaks mostly in MSM in Europe since mid-2016. CONCLUSION: As a consequence of the implementation of immunization in children, and the improvement in socio-economic, hygienic and sanitation factors, young adults are becoming increasingly susceptible to HAV infections. Here we add evidence in South America to the HA outbreaks described worldwide among young MSM, demonstrating the need to reinforce official policy of vaccination, in this group and adjust epidemiological surveillance, catch-up vaccination for adolescents, young adults and immunosuppressed patients.

Molecular screening of the human parvoviruses B19 and bocavirus 1 in the study of congenital diseases as applied to symptomatic pregnant women and children.

INTRODUCTION: B19 virus (B19V) and bocavirus 1 (HBoV1) are human pathogenic parvoviruses that are prevalent worldwide and are responsible for a diverse and not yet fully established spectrum of clinical manifestations. OBJECTIVE: To screen B19V and HBoV1 in patients with clinical manifestations associated with acquisition of the infection during gestation. METHODS: A retrospective, observational study was performed that included serum samples from patients without a previous known aetiology. B19V and HBoV1 were determined by end-point PCR. Positive samples were genotyped. RESULTS: A total of 106 serum samples were analysed, 61 from pregnant women and 45 from neonates and paediatric patients. None were positive for HBoV1, while B19V was detected in 37/106 [34.9 %, 95 % confidence interval (CI): 26.5-44.4] of the samples studied. In the group of pregnant women, 28/61 (45.9 %, 95 % CI: 34.0-58.3) were B19V-positive, and 2 of them had foetal anaemia followed by hydrops and foetal death, 3 were associated with a history of recurrent pregnancy loss and there was 1 case of spontaneous abortion. B19V was also detected in cases of maternal febrile exanthema, polyhydramnios, oligohydramnios and foetal ascites. In the group of children, 9/45 (20.0 %, 95 % CI: 10.9-33.8) neonatal patients were B19V-positive, and this was associated with foetal hydrops, TORCH syndrome and cardiac alterations. The nucleotide sequences analysed confirmed the identity of B19V genotype 1. CONCLUSIONS: We found no evidence to indicate the presence of HBoV1 in maternal blood or in the newborns/paediatric patients (hence providing no support for the supposed vertical transmission). On the other hand, the high frequency of B19V in the pathologies studied indicates the importance of molecular diagnosis in both the mother and the child. Future efforts should contribute to early detection and characterization of infections.