ABSTRACT
OBJECTIVES: COVID-19 vaccine breakthrough infections were frequently reported during circulation of the Omicron variant. The ANRS|MIE CoviCompareP study investigated these infections in adults vaccinated and boosted with BNT162b2 [Pfizer-BioNTech] and with/without SARS-CoV-2 infection before vaccination. METHODS: In the first half of 2021, healthy adults (aged 18-45, 65-74 and 75 or older) received either one dose of BNT162b2 (n = 120) if they had a documented history of SARS-CoV-2 infection at least five months previously, or two doses (n = 147) if they had no history confirmed by negative serological tests. A first booster dose was administered at least 6 months after the primary vaccination, and a second booster dose, if any, was reported in the database. Neutralizing antibodies (NAbs) against the European (D614G) strain and the Omicron BA.1 variant were assessed up to 28 days after the first booster dose. A case-control analysis was performed for the 252 participants who were followed up in 2022, during the Omicron waves. RESULTS: From January to October 2022, 78/252 (31%) had a documented symptomatic breakthrough infection after full vaccination: 21/117 (18%) in those who had been infected before vaccination vs. 57/135 (42%) in those who had not. In a multivariate logistic regression model, factors associated with a lower risk of breakthrough infection were older age, a higher number of booster doses, and higher levels of Omicron BA.1 NAb titers in adults with infection before vaccination, but not in those without prior infection. CONCLUSION: Our results highlight the need to consider immune markers of protection in association with infection and vaccination history.
ABSTRACT
OBJECTIVE: Viral rebounds inevitably follow interruption of antiretroviral treatment in HIV-1-infected individuals. The randomized ANRS 093 aimed at investigating whether a therapeutic immunization was effective in containing the long-term viral replication following discontinuation of antiretroviral drugs in patients. METHODS: Seventy HIV-1-infected patients effectively treated with antiretroviral drugs were randomized to continue treatment alone or in combination with four boosts of ALVAC 1433 and HIV-LIPO-6T vaccines followed by three cycles of subcutaneous interleukin-2. The impact of vaccination on viral replication was assessed by interrupting antiretroviral drugs first at week 40 and thereafter during follow-up until week 100. Antiretroviral drugs were re-initiated according to predefined criteria. RESULTS: The median cumulative time (days) off treatment was greater in the vaccine group (177) than in the control group (89) (P = 0.01). The proportion of time (mean, SE) without antivirals per-patient was 42.8% (5.1) and 26.5% (4.2) in the vaccine and control groups, respectively (P = 0.005). Viremia (median log10 copies/ml), 4 weeks following the first, second and third treatment interruption was higher in control patients (4.81, 4.44, 4.53) in comparison with vaccinated patients (4.48, 4.00, 3.66) (P = 0.42, 0.015 and 0.024, respectively). HIV-specific CD4 and CD8 T-cell responses elicited by the therapeutic immunization strongly correlated with the reduction of the time of antiviral therapy (P = 0.0027 and 0.016, respectively). CONCLUSION: Our findings provide evidence that therapeutic immunization significantly impacts on HIV-1 replication. This translated into a decrease of up to 40% in the duration of exposure to antiretroviral drugs over 15 months of patients' follow-up.
