Comparison of Antibody Response Elicited by ChAdOx1 and BNT162b2 COVID-19 Vaccine

Abstract

Background ChAdOx1 and BNT162b2 vaccines are currently commonly used against coronavirus disease 2019 worldwide. Our study was designed to determine the serostatus and relative levels of anti-S and neutralizing antibodies in patients who were administered either ChAdOx1 or BNT162b2 vaccine. In addition, we investigated whether the antibody response to each vaccine differed according to sex and age. Methods Healthcare workers (HCWs) at a general hospital who were vaccinated with two doses of either ChAdOx1 or BNT162b2 were invited to participate in this prospective cohort study. Blood samples of HCWs vaccinated with both ChAdOx1 doses over a period of 12 weeks were collected at weeks 4 and 8 post first vaccination and 2 weeks post second vaccination. Blood samples of HCWs vaccinated with BNT162b2 were collected in the third week after the first dose, and the second dose was then administered on the same day; two weeks post second dose (5 weeks after the first dose), blood samples were collected to assess the antibody response. The titers of anti-S antibodies against the severe acute respiratory syndrome coronavirus 2 spike (S) protein receptor-binding domain and the neutralizing antibodies in the collected blood were evaluated. Results Of the 309 HCWs enrolled in the study, 205 received ChAdOx1 and 104 received BNT162b2. Blood samples from participants receiving either the ChAdOx1 or BNT162b2 vaccine exhibited substantial anti-S and neutralizing antibody seropositivity subsequent to the second dose. All participants (100%) from both vaccine groups were seropositive for anti-S antibody, while 98% (201/205) of ChAdOx1-vaccinated individuals and 100% (104/104) of BNT162b2-vaccinated individuals were seropositive for neutralizing antibodies. The median levels of anti-S and neutralizing antibodies were significantly higher in the BNT162b2-vaccinated group than the ChAdOx1-vaccinated group; in particular, anti-S antibody titers of 1,020 (interquartile range, 571.0–1,631.0) U/mL vs. 2,360 (1,243–2,500) U/mL, P < 0.05, were recorded for the ChAdOx1 and BNT162b2 groups, respectively, and neutralizing antibody titers of 85.0 (65.9–92.1%) vs. 95.8 (94.4–96.6%), P < 0.05, were recorded for the ChAdOx1 and BNT162b2 groups, respectively. In the ChAdOx1 vaccine group, the neutralizing antibody level was significantly higher in women than in men (85.7 [70.3–92.5%] vs. 77.7 [59.2–91.0%], P < 0.05); however, the neutralizing antibody titer in the BNT162b2 vaccine group did not vary between the two sexes (95.9 [95.2–96.6%] vs. 95.2 [93.5–96.3%], P = 0.200). Analysis of the correlation of antibody profiles with age revealed that the levels of anti-S antibodies and signal inhibition rate (SIR) of neutralizing antibodies decreased significantly with age. Conclusion Both the ChAdOx1- and BNT162b2-vaccinated groups showed high s...

Anti-SARS-CoV-2 Neutralizing Antibody Responses after Two Doses of ChAdOx1 nCoV-19 vaccine (AZD1222) in Healthcare Workers

“…Although there are reports of Nab degradation after vaccination, the literature on the long-term responses of Nab titers, especially after AZD1222 (AstraZeneca, UK) vaccination, is still lacking. Kang et al [ 22 ] also reported Nab responses at 3 different time points identical to ours, except for 28-week group. They claim that there was no significant difference in Nab titer between 4 and 8 weeks after 1st dose of AZD1222 (AstraZeneca, UK).…”

“…Kang et al reported that seropositive rates after 1st and 2nd inoculation were 66.8% and 98.0% for AZD1222 (AstraZeneca, UK), and 87.5% and 100% for BNT162b2 vaccine [ 22 ]. Nam et al [ 24 ].…”

Evaluating the antibody response to SARS-COV-2 vaccination amongst kidney transplant recipients at a single nephrology centre

“…Lesny et al, similarly, found no relationship between the vaccine type and antibody response amongst hemodialysis patients receiving either the mRNA or the vector-based SARS-COV-2 vaccines [ 33 ]. On the other hand, a few recent studies within and outside the UK have reported higher seroconversion rates and neutralizing antibody titres in recipients of BNT162b2 compared to AZD1222 [ 34 – 36 ]. Of note is a recent sub-study of the UK OCTAVE study in which 920 KTR were screened for spike protein antibodies following 2 doses of either BNT162b2 (n = 490) or AZD1222 (n = 430) vaccines.…”

“…Another study that assessed neutralizing antibody levels following COVID-19 vaccination in hemodialysis patients in the UK also reported a suboptimal response to AZD1222. Two studies from Korea respectively evaluated the antibody responses against SARS-CoV-2 in healthcare workers, reported better antibody responses with BNT162b2 compared to AZD1222 [ 35 , 36 ].…”

Genetic immune response and antibody repertoire of heterologous ChAdOx1-BNT162b2 vaccination in a Korean cohort

“…Our study adds to a molecular understanding of findings that a heterologous ChAdOx1-BNT162b2 vaccination schedule promotes a more robust immune response than two doses of either BNT162b or ChAdOx1 2-4 . While several ChAd-ChAd heterologous vaccination studies 5,6 , including from South Korea 11,31 , have been published, this is the first report investigating the molecular immune response using bulk and single cell RNAseq as well as the antibody response to different variants, including the fast-spreading Omicron.…”