Rapid decline of humoral response to two doses of BNT162b2 vaccine in patients with solid cancer after six months: The urgent need of the additional dose!

INTRODUCTION: We previously reported on the immunogenicity and safety of BNT162b2 in a large cohort of patients with cancer after the first and second doses (Di Noia et al., 2021) [1]. Herein, we present result after six months of follow-up. METHODS: This prospective study included patients affected by solid tumors and afferent to our institution who received two doses of BNT162b2 vaccine. A cohort of vaccinated healthcare workers (HCW) was used as control-group. Both cohorts were evaluated for the titer of anti-Spike (S) IgG at prefixed time-points (TPs). Time-point 4 was scheduled at 24-26 weeks after the second dose. RESULTS: In the current analysis, 400 patients and 232 healthcare workers were evaluated. Responders (IgG > 15 AU/mL) in patients group were 86.5% compared with 94.4% among healthcare workers. Also the IgG titer at TP4 was significantly inferior in patients than in healthcare workers (70.81 vs 134.64 AU/ml, p < 0.001). There was a more rapid decline of the antibody level from TP3 to TP4 in patients than in healthcare workers (1.78 vs 1.3 fold). The estimated IgG half-life was significantly shorter for patients (73 days) than in healthcare workers (118 days) as well as the time to reach negative serological status (340 vs 532 days). CONCLUSION: The decline of humoral response to the vaccine observed in patients with solid cancer after six months from the first dose support the urgent need of an early additional dose.

Immunogenicity and Safety of COVID-19 Vaccine BNT162b2 for Patients with Solid Cancer: A Large Cohort Prospective Study from a Single Institution.

PURPOSE: We assessed the immunogenicity and safety of the BNT162b2 vaccine in a large cohort of patients with cancer (CP). EXPERIMENTAL DESIGN: From March 1, 2021 to March 20, 2021, this prospective cohort study included 816 CP afferent to our institution and eligible for the vaccination. A cohort of 274 health care workers (HCW) was used as age- and sex-matched control group. BNT162b2 was administered as a two-dose regimen given 21 days apart. Blood samples to analyze anti-Spike (S) IgG antibodies (Ab) were collected prevaccination [timepoint (TP) 0], and at 3 weeks (TP1) and 7 weeks (TP2) after the first dose. RESULTS: Patients characteristics: median age 62 (range, 21-97); breast/lung cancer/others (31/21/48%); active treatment/follow-up (90/10%). In the whole CP cohort, the serologic response rate (RR) and the titre of anti-S IgG significantly increased across the TPs; at TP2, the responders (IgG >15 AU/mL) were 94.2%. Active chemotherapy and chronic use of steroids were independent predictors of lower RR. Adverse events (AE) after the booster predicted higher likelihood of response (OR, 4.04; 95% confidence interval, 1.63-9.99; P = 0.003). Comparing the matched cohorts, the responders were significantly lower in CP than in HCW at TP1 (61.2% vs. 93.2%) and TP2 (93.3% vs. 100%), while the geometric mean concentration of IgG did not significantly differ at TP2 being significantly lower in CP (23.3) than in HCW (52.1) at TP1. BNT162b2 was well tolerated in CP; severe-grade AEs were 3.5% and 1.3% after the first and second doses, respectively. CONCLUSIONS: BNT162b2 assures serologic immunization without clinically significant toxicity in CP. The second dose is needed to reach a satisfactory humoral response.

Antibody Persistence 6 Months Post-Vaccination with BNT162b2 among Health Care Workers.

BACKGROUND: We present immunogenicity data 6 months after the first dose of BNT162b2 in correlation with age, gender, BMI, comorbidities and previous SARS-CoV-2 infection. METHODS: An immunogenicity evaluation was carried out among health care workers (HCW) vaccinated at the Istituti Fisioterapici Ospitalieri (IFO). All HCW were asked to be vaccine by the national vaccine campaign at the beginning of 2021. Serum samples were collected on day 1 just prior to the first dose of the vaccine and on day 21 just prior to the second vaccination dose. Thereafter sera samples were collected 28, 49, 84 and 168 days after the first dose of BNT162b2. Quantitative measurement of IgG antibodies against S1/S2 antigens of SARS-CoV-2 was performed with a commercial chemiluminescent immunoassay. RESULTS: Two hundred seventy-four HWCs were analyzed, 175 women (63.9%) and 99 men (36.1%). The maximum antibody geometric mean concentration (AbGMC) was reached at T2 (299.89 AU/mL; 95% CI: 263.53-339.52) with a significant increase compared to baseline (p < 0.0001). Thereafter, a progressive decrease was observed. At T5, a median decrease of 59.6% in COVID-19 negative, and of 67.8% in COVID-19 positive individuals were identified with respect to the highest antibody response. At T1, age and previous COVID-19 were associated with differences in antibody response, while at T2 and T3 differences in immune response were associated with age, gender and previous COVID-19. At T4 and T5, only COVID-19 positive participants demonstrated a greater antibody response, whereas no other variables seemed to influence antibody levels. CONCLUSIONS: Overall our study clearly shows antibody persistence at 6 months, albeit with a certain decline. Thus, the use of this vaccine in addressing the COVID-19 pandemic is supported by our results that in turn open debate about the need for further boosts.

The first report on coronavirus disease 2019 (COVID-19) vaccine refusal by patients with solid cancer in Italy: Early data from a single-institute survey.

INTRODUCTION: Patients with cancer have an increased risk of complications from coronavirus disease 2019 (COVID-19) infection, including death, and thus, they were considered as high-priority subjects for COVID-19 vaccination. We report on the compliance with the COVID-19 vaccine of patients affected by solid tumours. MATERIALS AND METHODS: Patients with cancer afferent to Medical Oncology 1 Unit of Regina Elena National Cancer Institute in Rome were considered eligible for vaccination if they were receiving systemic immunosuppressive antitumor treatment or received it in the last 6 months or having an uncontrolled advanced disease. The Pfizer BNT162b2 vaccine was proposed to all candidates via phone or during a scheduled visit. The reasons for refusal were collected by administrating a 6-item multiple-choice questionnaire. RESULTS: From 1st March to 20th March 2021, of 914 eligible patients, 102 refused vaccination (11.2%, 95% confidence interval [CI] 9.1-13.2). The most frequent (>10%) reasons reported were concerns about vaccine-related adverse events (48.1%), negative interaction with concomitant antitumor therapy (26.7%), and the fear of allergic reaction (10.7%). The refusal rate (RR) after 15th March (date of AstraZeneca-AZD1222 suspension) was more than doubled compared with the RR observed before (19.7% versus 8.6%, odds ratio [OR] 2.60, 95% CI 1.69-3.99; P < 0.0001). ECOG-PS 2 was associated with higher RR compared with ECOG-PS 0-1 (OR 2.94, 95% CI 1.04-8.34; P = 0.04). No statistically significant differences in RR according to other clinical characteristics were found. CONCLUSIONS: Our experience represents the first worldwide report on the adherence of patients with cancer to COVID-19 vaccination and underlines how regulatory decisions and media news spreading could influence the success of the campaign.