ABSTRACT
Background. In-vitro neutralizing antibody (Ab) titers correlated with ~250 IU/ mL Spike Ig Ab level for the Delta COVID-19 variant, establishing the 2021 French and Swiss cutoff for booster guidance. In a New York City healthcare clinic where those guidelines were adopted, we aimed to quantify vaccination responses in HIV + and HIV- individuals to assess the utility of quantifying antibodies to guide booster timing. Methods. Adults who were fully vaccinated against SARS-CoV-2 virus (i.e., 2 Pfizer, 2 Moderna or 1 J&J vaccine) were included if >1 Roche SARS-CoV-2 Semi-Quant Spike Ig Ab test was performed >21 days after vaccination and before any booster (through 03DEC2021). Vaccine response was assessed at the first Ab test and considered adequate (>250 IU/mL) or inadequate (low: >=51 to <=250 IU/ mL;no response: < 51 IU/mL). The rate of Ab decline was estimated with linear regression, using all sequential Ab tests over the first 6 months between vaccination and boosting. Analyses were stratified by vaccine type, HIV status and CD4 count in HIV+ ( >200 cells/muL cutoff). Results. Out of 1979 patients, 869 completed their primary vaccinations, of whom 825 (95%) had >=1 eligible Ab test (HIV+: 512;HIV-: 313;Table). Overall, 83% had an adequate immune response to vaccination (Pfizer: 82%, Moderna: 94%, J&J: 51%), with similar findings regardless of HIV status and CD4 count (Figure 1). In those with >=2 Ab tests within six months between vaccination and boosting, Ab levels declined at a rate of 91 IU/mL per month (95% CI: -138, -44). While some variation was observed, rates of Ab decay were generally consistent across vaccine, HIV status and CD4 count strata (Figure 2). Only 1/7 breakthrough COVID-19 infections occurred post booster (6 days later Conclusion. In the pre-omicron era, primary COVID immunization with a mRNA vaccine generally yielded adequate Ab responses, although inadequate responses were observed in 19% of Pfizer, 6% of Moderna, and 49% of J&J vaccine recipients. Ab levels decreased at an average rate of 91 IU/mL per month after primary immunization. Variability in vaccine responses and Ab declines show the utility of measuring spike Ig Ab levels rather than using empiric time frames for booster guidance. Omicron-specific quantitative IgG neutralization levels must be established to inform preventative care.
ABSTRACT
Background. The COVID-19 pandemic has disrupted health care services for people living with HIV (PLWH). This study aimed to compare rates of clinical visits, viral load monitoring and antiretroviral therapy (ART) regimen discontinuation among virally suppressed PLWH in the US before and during the COVID pandemic. Methods. The study population consisted of ART-experienced PLWH ≥18 years of age and active in care in the OPERA cohort within 2 years prior to 31OCT2020. Virally suppressed PLWH (i.e., viral load < 200 copies/mL) were included if they switched to either dolutegravir/lamivudine or a dolutegravir- or bictegravir-based 3-drug regimen between 01MAY2019 and 30APR2020. The study periods spanned from 01MAY2019 to 28FEB2020 (pre-COVID) and 01MAR2020 to 31OCT2020 (during COVID). Incidence rates of clinical visits, viral load measurements and regimen discontinuation were estimated using univariate Poisson regression for both study periods. In-person visits comprised any scheduled or walk-in outpatient, inpatient, emergency or laboratory visit. Telehealth visits comprised any phone or video encounters. Results. The study included 4806 PLWH in the pre-COVID and 4992 in the COVID period. Rates of in-person visits were reduced almost 2-fold during COVID, while telehealth visits increased almost 9-fold, resulting in an overall reduction in any visits rates from 10.07 visits per person-year (95% CI: 9.93, 10.21) pre-COVID to 7.10 (95% CI: 7.01, 7.19) during COVID [Fig 1]. Rates of viral load measurements dropped from 2.99 viral loads per person-year (95% CI: 2.92, 3.07) pre-COVID to 1.97 (95% CI: 1.92, 2.02) during COVID [Fig 2]. Regimen discontinuation rates were also reduced from 14.3 discontinuations per 100 person-years pre-COVID (95% CI: 12.7, 16.1) to 9.6 (95% CI: 8.6, 10.8) during COVID [Fig 3]. In both study periods, virologic failures were detected in < 1% of PLWH with ≥ 1 viral load. Conclusion. The COVID pandemic has led to an important reduction in the frequency and type of clinical follow-up visits and viral load monitoring among virally suppressed PLWH in the US. A reduction in regimen discontinuation rates was also observed, presumably associated to less frequent follow-up. The long-term impact of the pandemic on HIV care remains uncertain.