Concomitant administration of seasonal influenza and COVID-19 mRNA vaccines.

Current clinical guidelines support the concomitant administration of seasonal influenza vaccines and COVID-19 mRNA boosters vaccine. Whether dual vaccination may impact vaccine immunogenicity due to an interference between influenza or SARS-CoV-2 antigens is unknown. We aimed to understand the impact of mRNA COVID-19 vaccines administered concomitantly on the immune response to influenza vaccines. For this, 128 volunteers were vaccinated during the 22-23 influenza season. Three groups of vaccination were assembled: FLU vaccine only (46, 35%) versus volunteers that received the mRNA bivalent COVID-19 vaccines concomitantly to seasonal influenza vaccines, FluCOVID vaccine in the same arm (42, 33%) or different arm (40, 31%), respectively. Sera and whole blood were obtained the day of vaccination, +7, and +28 days after for antibody and T cells response quantification. As expected, side effects were increased in individuals who received the FluCOVID vaccine as compared to FLU vaccine only based on the known reactogenicity of mRNA vaccines. In general, antibody levels were high at 4 weeks post-vaccination and differences were found only for the H3N2 virus when administered in different arms compared to the other groups at day 28 post-vaccination. Additionally, our data showed that subjects that received the FluCOVID vaccine in different arm tended to have better antibody induction than those receiving FLU vaccines for H3N2 virus in the absence of pre-existing immunity. Furthermore, no notable differences in the influenza-specific cellular immune response were found for any of the vaccination groups. Our data supports the concomitant administration of seasonal influenza and mRNA COVID-19 vaccines.

Three double-dose reinforced hepatitis B revaccination scheme for patients with cirrhosis unresponsive to the standard regimen: an open-label randomised clinical trial.

OBJECTIVE: We aimed to compare the response rates between two different hepatitis B virus vaccination schedules for cirrhotic subjects who were non-responders to the first three 40 µg doses (month 0-1-2), and identify factors associated with the final response. DESIGN: A total of 120 cirrhotic patients (72.5% decompensated) were randomised at a 1:1 ratio to receive a single 40 µg booster vaccination at month 6 (classical arm) versus an additional round of three new 40 µg doses administered at monthly intervals (experimental arm). The main outcome was the rate of postvaccinal anti-hepatitis B surface antibodies levels ≥10 mIU/mL. RESULTS: Efficacy by ITT analysis was higher in the experimental arm (46.7%) than in the classical one (25%); OR 2.63, p=0.013. The experimental arm increased response rates compared with the classical one from 31% to 68% (OR 4.72; p=0.007), from 24.4% to 50% (OR 3.09; p=0.012) and from 24.4% to 53.8% (OR 3.62; p=0.007), in Child A, Model for End-Stage Liver Disease (MELD) <15 and MELD-Na<15 patients, respectively. Patients with more advanced liver disease did not benefit from the reinforced scheme. Both regimens showed similar safety profiles. Multivariable analysis showed that the experimental treatment was independently response associated when adjusted across three logistic regression models indicating equivalent cirrhosis severity. CONCLUSION: For cirrhotic patients, the revaccination of non-responders to the first three dose cycle, with three additional 40 µg doses, achieved significantly better response rates to those obtained with an isolated 40 µg booster dose. TRIAL REGISTRATION NUMBER: NCT01884415.

West Nile virus outbreak in humans and epidemiological surveillance, west Andalusia, Spain, 2016.

In Andalusia, Spain, West Nile virus (WNV) surveillance takes place from April to November, during the active vector period. Within this area seroconversion to this virus was evidenced in wild birds in 2004, affecting horses and two humans for the first time in 2010. Since 2010, the virus has been isolated every year in horses, and national and regional surveillance plans have been updated with the epidemiological changes found. WNV is spreading rapidly throughout southern Europe and has caused outbreaks in humans. Here we describe the second WNV outbreak in humans in Andalusia, with three confirmed cases, which occurred between August and September 2016, and the measures carried out to control it. Surveillance during the transmission season is essential to monitor and ensure prompt identification of any outbreaks.