Neutralizing antibodies to Omicron after the fourth SARS-CoV-2 mRNA vaccine dose in immunocompromised patients highlight the need of additional boosters

IntroductionImmunocompromised patients have been shown to have an impaired immune response to COVID-19 vaccines.MethodsHere we compared the B-cell, T-cell and neutralizing antibody response to WT and Omicron BA.2 SARS-CoV-2 virus after the fourth dose of mRNA COVID-19 vaccines in patients with hematological malignancies (HM, n=71), solid tumors (ST, n=39) and immune-rheumatological (IR, n=25) diseases. The humoral and T-cell responses to SARS-CoV-2 vaccination were analyzed by quantifying the anti-RBD antibodies, their neutralization activity and the IFN-γ released after spike specific stimulation.ResultsWe show that the T-cell response is similarly boosted by the fourth dose across the different subgroups, while the antibody response is improved only in patients not receiving B-cell targeted therapies, independent on the pathology. However, 9% of patients with anti-RBD antibodies did not have neutralizing antibodies to either virus variants, while an additional 5.7% did not have neutralizing antibodies to Omicron BA.2, making these patients particularly vulnerable to SARS-CoV-2 infection. The increment of neutralizing antibodies was very similar towards Omicron BA.2 and WT virus after the third or fourth dose of vaccine, suggesting that there is no preferential skewing towards either virus variant with the booster dose. The only limited step is the amount of antibodies that are elicited after vaccination, thus increasing the probability of developing neutralizing antibodies to both variants of virus.DiscussionThese data support the recommendation of additional booster doses in frail patients to enhance the development of a B-cell response directed against Omicron and/or to enhance the T-cell response in patients treated with anti-CD20

Awareness, discussion and non-prescribed use of HIV pre-exposure prophylaxis among persons living with HIV/AIDS in Italy: a Nationwide, cross-sectional study among patients on antiretrovirals and their treating HIV physicians

Background: Before Pre-Exposure Prophylaxis (PrEP) was officially recommended and made available, a few surveys among gay and bisexual men, and persons living with HIV/AIDS (PLWHA), identified an informal use of antiretrovirals (ARVs) for PrEP among HIV-negative individuals. Before PrEP availability in Italy, we aimed to assess whether PLWHA in Italy shared their ARVs with HIV-negative individuals, whether they knew people who were on PrEP, and describe the level of awareness and discussion on this preventive measure among them and people in their close circle. Methods: Two anonymous questionnaires investigating personal characteristics and PrEP awareness, knowledge, and experience were proposed to HIV specialists and their patients on ARVs in a one-week, cross-sectional survey (December 2013-January 2014). Among PLWHA, a Multivariable Logistic Regression analysis was conducted to identify factors associated with PrEP discussion with peers (close circle and/or HIV associations), and experience (use in close circle and/or personal ARV sharing). Results: Eighty-seven specialists in 31 representative Infectious Diseases departments administered the questionnaire to 1405 PLWHA. Among specialists, 98% reported awareness, 65% knew the dosage schedule, and 14% had previously suggested or prescribed PrEP. Among PLWHA, 45.6% were somehow aware, discussed or had direct or indirect experience of PrEP: 38% "had heard" of PrEP, 24% were aware of studies in HIV-negative individuals demonstrating a risk reduction through the use of ARVs, 22% had discussed PrEP, 12% with peers; 9% reported PrEP use in close circle and 1% personal ARV sharing. Factors predictive of either PrEP discussion with peers or experience differed between men and women, but across all genders were mainly related to having access to information, with HIV association membership being the strongest predictor. Conclusions: At a time and place where there were neither official information nor proposals or interventions to guide public policies on PrEP in Italy, a significant number of PLWHA were aware of it, and approximately 10% reported PrEP use in their close circle, although they rarely shared their ARVs with uninfected people for this purpose. Official policies and PrEP availability, along with implementation programs, could avoid risks from uncontrolled PrEP procurement and self-administration practices