key: cord-0748375-ashxoaav authors: SINGH, A. K.; Phatak, S. R.; SINGH, R.; Bhattacharjee, K.; Singh, N. K.; Gupta, A.; Sharma, A. title: Antibody Response after Second-dose of ChAdOx1-nCOV (CovishieldTM) and BBV-152 (CovaxinTM) among Health Care Workers in India: Final Results of Cross-sectional Coronavirus Vaccine-induced Antibody Titre (COVAT) study date: 2021-06-04 journal: nan DOI: 10.1101/2021.06.02.21258242 sha: 1ac0c08309129b21f2a5a259166f219c14b8de17 doc_id: 748375 cord_uid: ashxoaav Background: We assessed the humoral immune response after the completion of two doses of both ChAdOx1-nCOV (CovishieldTM) and BBV-152 (CovaxinTM) vaccines in Indian health care workers (HCW). Methods: A Pan-India, Cross-sectional, Coronavirus Vaccine-induced Antibody Titre (COVAT) study was conducted that measured SARS-CoV-2 anti-spike binding antibody quantitatively, 21 days or more after the first and second dose of two vaccines in both severe acute respiratory syndrome (SARS-CoV-2) naive and recovered HCW. Primary aim was to analyze antibody response (seropositivity rate and median [inter-quartile range, IQR] antibody titre) following each dose of both vaccines and its correlation to age, sex, blood group, body mass index (BMI) and comorbidities. Here we report the final results of anti-spike antibody response after the two completed doses. Results: Among the 515 HCW (305 Male, 210 Female), 95.0% showed seropositivity after two doses of both vaccines. Of the 425 Covishield and 90 Covaxin recipients, 98.1% and 80.0% respectively, showed seropositivity. However, both seropositivity rate and median (IQR) rise in anti-spike antibody was significantly higher in Covishield vs. Covaxin recipient (98.1 vs. 80.0%; 127.0 vs. 53 AU/mL; both p<0.001). This difference persisted in 457 SARS-CoV-2 naive cohorts and propensity-matched (age, sex and BMI) analysis of 116 cohorts. While no difference was observed in relation to sex, BMI, blood group and any comorbidities; people with age >60 years or those with type 2 diabetes had a significantly lower seropositivity rates. Both vaccine recipients had similar solicited mild to moderate adverse events and none had severe or unsolicited side effects. In SARS-CoV-2 naive cohorts, sex, presence of comorbidities, and vaccine type were independent predictors of antibody positivity rate in multiple logistic regression analysis. Conclusions: Both vaccines elicited good immune response after two doses, although seropositivity rates and median anti-spike antibody titre was significantly higher in Covishield compared to Covaxin arm. Nation-wide vaccination against the Severe Acute Respiratory Syndrome imidazoquinoline Toll-like receptor 7/8 (TLR 7/8) agonist to boost cell-mediated immunity. Each dose (0.5 ml) of Covaxin contains 6 µg dose of whole virion inactivated corona virus antigen strain NIV-2020-770. While, early data from available phase 3 randomized clinical trials (RCTs) suggested that these two vaccines are safe and effective [1] [2] [3] , there is still a paucity of information as to how much and how long, these novel vaccines can elicit an immune response, both at . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this preprint this version posted June 4, 2021. ; https://doi.org/10.1101/2021.06.02.21258242 doi: medRxiv preprint humoral and cellular level in real-world settings. Moreover, the antibody kinetics after the completion of 2 doses of Covishield and Covaxin and thereafter, over a period of time is less well known. We have reported the preliminary results of ongoing Cross-sectional Coronavirus Vaccine-induced Antibody Titre (COVAT) study that assessed the anti-spike antibody humoral response 21-day after the first dose but before the second dose of both Covishield and Covaxin [4] . In this analysis, we report the binding anti-spike antibody kinetics after the completion of second dose of two vaccines from the ongoing COVAT study. This report followed the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) reporting guideline for cross-sectional studies [5] . COVAT study is an ongoing, pan-India, cross-sectional study that was approved by the ethical committee of Thakershy Charitable Trust, Ahmedabad, Gujarat, India. Written informed consent were taken from all the participants who participated in this study, voluntarily. All adult health care workers of more than 18 years of age who received the first dose of vaccine were eligible to participate in this study including those who had recovered from the COVID-19 in the recent past (> 6 weeks before the first dose). Individuals with current confirmed SARS-CoV-2 infection . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this preprint this version posted June 4, 2021. ; https://doi.org/10.1101/2021.06.02.21258242 doi: medRxiv preprint and those diagnosed within 6-weeks were excluded from the study. All subjects have received the two doses of either vaccine 0.5 ml intramuscularly in deltoid region of arm. Data collection for this analysis started since the January 16, 2021 (first day of vaccination amongst HCW) until May 15, 2021 (data-lock date). India had nearly 25 million cases of COVID-19 with an average case reported per day ranged from 0.1-0.4 million during this period, with a peak of >0.4 million case on a single day on May 7, 2021. Clinical data was collected from all eligible participants including age, sex, blood groups, body mass index (BMI), past history of confirmed SARS-CoV-2 infection, any comorbidities, presence of diabetes mellitus (type 1 [T1DM] and type 2 [T2DM]), hypertension (HTN) including its duration and treatment received, dyslipidemia, ischemic heart disease (IHD), chronic kidney disease (CKD) and cancer. Additional data was collected for any adverse events post-vaccination after second dose and subsequent SARS-CoV-2 infection (breakthrough infections). Accordingly, all participants were instructed to record and report the severity of conventional or solicited adverse events (fever, pain, induration, swelling, redness, muscle pain, headache, fatigue, rash, pruritus or acute allergic reaction) to site investigators occurring within a week of vaccination. Severity of solicited adverse . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review) The copyright holder for this preprint this version posted June 4, 2021. ; https://doi.org/10.1101/2021.06.02.21258242 doi: medRxiv preprint events was graded as nil, mild (recovered within 24 to 48-hour) to moderate (>48hour to <7-days) and severe (requiring hospitalization), depending upon the intensity and duration of adverse event(s). Similarly, a record of unexpected or unsolicited adverse events of bleeding, thrombo-embolic episode, bells' palsy, seizure or other neurological manifestations, occurring from day 0 to 6 month is also being captured. Data collection for unsolicited adverse events and breakthrough infections is still ongoing and will be continued for 6-months after the second dose. Breakthrough infections are reported as per the given proforma that include-timing and severity, defined as mild (in-house or hospital treatment not requiring oxygen therapy), moderate (requiring oxygen supplementation but not requiring assisted ventilation, and severe (requiring ventilator). As reported previously, anti-spike antibody titre is being measured at four timepoints: day 21 after the first dose until the day before the second dose; day 21-28 of second dose, day 83-97 (3-months) and day 173-187 (6-months) after the second dose. Second blood samples (5 ml) were collected from eligible from day 21-36 after the second dose of each vaccine. An additional 7 days for second blood sample was allowed due to widespread lockdown. All samples were collected as either serum or plasma using EDTA vials from each participant and analyzed at Central laboratory of Neuberg, Supratech at Ahmedabad, Gujarat, India. The IgG antibodies to SARS-. CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review) The copyright holder for this preprint this version posted June 4, 2021. ; https://doi.org/10.1101/2021.06.02.21258242 doi: medRxiv preprint CoV-2 directed against the spike protein (S-antigen, both S1 and S2 protein) were assayed with LIASON ® S1/S2 quantitative antibody detection kit (DiaSorin Saluggia, Italy) using indirect chemiluminescence immunoassay (CLIA Descriptive and inferential statistical analysis has been carried out for the present study. Normality of the data was assessed by Shapiro-Wilk test and visually by QQ plot for Covishield and Covaxin subgroups. Data on continuous scale was presented as Median (Interquartile range, IQR) and categorical data were presented as number (%). A two-sided P value of < 0.05 was considered as statistically significant. Chi-. CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review) The copyright holder for this preprint this version posted June 4, 2021. square test was used to find the significance of study parameters on categorical scale between two or more groups. Mann-Whitney test was utilized to assess two nonparametric groups and Kruskal-Wallis test was used to compare the differences among two or multiple data group for data on continuous scale. To compare the antibody kinetics between two vaccines, we also carried out a propensity-matched comparison of the two groups. A propensity score was generated taking into consideration age, sex and BMI of the SARS-CoV-2 naïve participants. Participants having similar scores were matched and two groups were compared accordingly. Moreover, multiple logistic regression analysis was also conducted to find out whether any independent factors were associated with a blunted response to vaccine in anti-spike antibody generation following first dose of vaccination. Additionally, in order to provide more reliable information on the independent predictors of antibody levels, explanatory variables were dummy coded and a log transformation of the outcome variable was done to perform multiple regression analysis. The . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. Table 1 summarizes the baseline characteristics of 515 cohorts. A total of 515 (305 male, 210 female) participants' data was analyzed. Out of these 425 and 90 had received both doses of Covishield and Covaxin respectively. Overall, . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review) . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this preprint this version posted June 4, 2021. ; https://doi.org/10.1101/2021.06.02.21258242 doi: medRxiv preprint 88.0%, p=0.008) vs. longer duration (>5 years). Intriguingly, no significant difference in seropositivity rate was observed between SARS-CoV-2 naïve vs. people with past history of SARS-CoV-2 infection (94.3 vs. 100.0%, p=0.06) after the two complete doses of both vaccines. No differential antibody seropositivity rate was observed in relation to types of blood group, presence or absence of dyslipidemia, IHD and treatment regime of DM and HTN ( Table 2) . Since past history of SARS-CoV-2 infection can interfere with seropositivity to antispike antibody, we additionally analyzed the seropositivity rate after excluding SARS-CoV-2 recovered (n=58) cohorts. Importantly, in this analysis of 457 cohorts' results were similar and consistent. Seropositivity rate after the two complete doses was significantly higher in Covishield compared to Covaxin recipients (97.8 vs. 79.3%; p <0.001) (Supplementary table 1). In the propensity-matched analysis of 116 SARS-CoV-2 naïve cohorts (58 participants in each arm) after the adjustment for age, sex and BMI; seropositivity rates were significantly higher in Covishield arm compared to the Covaxin (98.3% vs. 82.8%, p=0.004). Age ≤60 years had a higher seropositivity rate vs. >60-years . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this preprint this version posted June 4, 2021. ; https://doi.org/10.1101/2021.06.02.21258242 doi: medRxiv preprint (98.5 vs. 79.6%, p=0.001) and presence of T2DM was associated with a lesser seropositivity rate compared to those without (92.0 vs. 50.0%, p=0.005) ( Table 3) . The median (IQR) rise in anti-spike antibody was significantly higher (p<0.001) in Multiple logistic regression analysis (to identify the independent predictors for nonresponder rate based on development of SARS-CoV-2 Anti-spike antibody) suggests that amongst all the variables analyzed, three variables such as-sex, presence of comorbidities, and vaccine type were independent predictors of antibody response rate. Associated co-morbidities were significantly related to an increase in the nonresponder rate by more than 4 folds (Odds Ratio [OR] 4.68; 95% CI, 1.382 -15.839; p=0.013), male gender also significantly increased the non-responder rate by more . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this preprint this version posted June 4, 2021. ; https://doi.org/10.1101/2021.06.02.21258242 doi: medRxiv preprint than 3 folds (OR 3.37; 95% CI, 1.221 -9.321; p=0.019). Notably, recipients of Covishield had a significantly lower non-responder rate by 41% (OR 0.59; 95% CI, 0.021 -0.659; p<0.001), compared to those who received Covaxin (Table 5) . In a multiple linear regression model with log transformed antibody levels as outcome variable, we found presence of co-morbidity, sex, vaccine type and past history of COVID-19 infection as independent predictors of antibody titre. The R value of the model represents the simple correlation and is 0.493, which indicates a moderate degree of correlation. The overall R 2 value is 0.247 indicating 24.7% of the total variation in the dependent variable (antibody titre) can be explained by our model. The multiple regression analysis (to identify the independent predictors for SARS-CoV-2 Anti-spike antibody titre) suggests that amongst all the variables analyzed, four variables such as-presence of comorbidity, sex, past history of SARS-CoV-2 infection and vaccine type were independent predictors of antibody titre levels. While presence of comorbidity resulted in decrease in the antibody titre by 13% (β=0.87; 95% CI, 0.79-0.97; p=0.010), female gender was found to have 9% greater antibody titre compared to males (β=1.09; 95% CI:1.02-1.17; p=0.018). SARS-CoV-2 naïve participants were associated with significantly lower antibody titre by 37% (β=0.63; 95% CI, 0.57-0.71; p<0.001). Notably, recipients of Covaxin . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this preprint this version posted June 4, 2021. ; https://doi.org/10.1101/2021.06.02.21258242 doi: medRxiv preprint had a significantly lower antibody titre by 32% ((β=0.68; 95%CI, 0.62-0.74; p<0.001), as compared to those who received Covishield (Supplementary table 3) . In the overall post-vaccination cohort, the Covishield recipients reported a higher incidence of mild to moderate side-effects in 18.1% (77/425) patients compared to 11.1% (10/90) patients in Covaxin arm after the second dose of vaccine, however, it didn't reach statistical significance (p=0.11). Notably, in the propensity-matched cohort, any side-effects (mild to moderate) post vaccination was also similar (p=0.13) in the Covishield arm 8/58 (13.79%) vs. Covaxin arm 6/58(10.34%). No serious solicited and any unsolicited side effects were noted. Table 4 ). Summarily, this cross-sectional COVAT study reported an overall 95.0% (489/515) seropositivity rate after the two complete doses of both vaccines in entire cohorts that include both SARS-CoV-2 naïve and recovered individuals (Covishield 98.1% and Covaxin 80.0%, respectively). While seropositivity rates after two complete doses was 97.8% and 79.3% with Covishield and Covaxin, respectively in SARS-CoV-2 naïve individuals; 100% of cohorts with a past history of SARS-CoV-2 were seropositive after the two doses of both vaccines. Notably, while both vaccines showed an increase in seropositivity and median (IQR) anti-spike antibody titre after the second dose, Covaxin gained a significant increase in both seropositivity and antibody titre only after the two completed doses. Contrarily, Covishield showed a good seropositivity rate and a 4-fold rise in median antibody titre even after a single . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this preprint this version posted June 4, 2021. ; https://doi.org/10.1101/2021.06.02.21258242 doi: medRxiv preprint dose. One dose of either vaccine yielded a very high seropositivity and anti-spike antibody titre in SARS-CoV-2 recovered individuals ( Table 6 ). There was no significant difference in seropositivity rate with regard to age, sex, BMI, blood group and any comorbidities including its duration and treatment, except that the participants with T2DM and T2DM or HTN of >5-year duration had a significantly less seropositive rate compared to those without and of <5-year duration, respectively. Importantly, median titre of antibody was significantly higher in females compared to the males. Notably, no difference in seropositivity rate was observed amongst SARS-CoV-2 naïve vs. SARS-CoV-2 recovered cohorts after the two completed doses of both vaccines, however, median (IQR) anti-spike antibody titre was significantly higher in later compared to the former. Any adverse side effects post-vaccination was similar in Covishield and Covaxin recipient and were mild to moderate in nature. Surprisingly, the seropositivity (responder) rate and median anti-spike antibody titre was significantly higher in Covishield recipients, compared to the Covaxin. Whether this differential finding between two vaccines is related to a lesser number of participants in Covaxin arm compared to the Covishield, or due to the difference in characteristics of participants, or due to the difference between the type of vaccine-vector-based vs. inactivated whole virion, or related to differential immunogenic response due to the difference in the loading dose of antigen in each vaccine -is not exactly known -and need further studies. . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this preprint this version posted June 4, 2021. ; https://doi.org/10.1101/2021.06.02.21258242 doi: medRxiv preprint Nevertheless, even in age-, sex-and BMI-matched propensity analysis, seropositivity rate and median anti-spike antibody titre was significantly higher with Covishield compared to Covaxin in SARS-CoV-2 naïve recipients. Notably, sex, presence of comorbidities, and type of vaccine used were an independent predictor of antibody response in multiple regression analysis. Our findings are similar to published evidence in randomized controlled trials The larger question is whether humoral antibody response to a vaccine correlates with the efficacy (reduction in severity and mortality due to COVID-19). Although the correlation of antibody titre to the vaccine efficacy is less well understood, NAb . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. To the best of our knowledge, this Pan-India cross-sectional COVAT study would be the first of its kind that has involved HCW from 13 States and 22 cities and reporting anti-spike antibody kinetics after two completed doses of two different vaccines. However, we also acknowledge several limitations. Firstly, in the present study, we have used a convenience sampling amounting to selection bias. A community-based study in a larger population with multi-stage sampling would be an ideal sampling method. Secondly, we used a binary logistic regression (to identify . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this preprint this version posted June 4, 2021. ; https://doi.org/10.1101/2021.06.02.21258242 doi: medRxiv preprint the predictors of non-response to vaccines) which primarily assumes linearity between the explanatory variable and the outcome variable, hence this model may miss out any predictor variable which may have non-linear relationship with the outcome variable. Thirdly, we have measured only anti-spike binding antibody and could not assess NAb and cell-mediated immune response such as Th-1 and Th-2 dependent antibody or cytokines (primarily due to the lack of standardized commercial labs in India). Fourth, we could not measure the baseline anti-spike antibody titre prior to the vaccination, because of logistic issue due to lockdown. Finally, two value of short-term anti-spike antibody as evaluated in this report may not necessarily predict the efficacy of vaccine, nor the absence of seropositivity confer failure of vaccine in absence of NAb and T-cell response assessment. In conclusion, this cross-sectional study after the completion of two doses of both vaccines suggests that both vaccines induce seropositivity to anti-spike antigen in 95% of SARS-COV-2 naïve and recovered individuals after 3-weeks. Whether any real difference in inducing immunogenicity exists between two vaccines can only be meaningfully demonstrated through a head-to-head RCT. . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this preprint this version posted June 4, 2021. ; https://doi.org/10.1101/2021.06.02.21258242 doi: medRxiv preprint We would like to thank all the participants who volunteered for this study. We express our sincere gratitude and acknowledgment to our Indian regional coordinators for the smooth conduct of this study that include (in alphabetical order) -Drs. Akash Kumar Singh (Vadodara), Amit Gupta (Noida), Anuj Maheshwari AKS and SRP conceptualized and designed the study. NKS, AG and AS monitored the study and captured the data at all point of time. AKS, KB and RS conducted the statistical analysis. AKS and RS wrote the first draft. AKS, KB and RS revised the . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this preprint this version posted June 4, 2021. ; https://doi.org/10.1101/2021.06.02.21258242 doi: medRxiv preprint manuscript. All authors gave their intellectual inputs while preparing the manuscript and agreed mutually to submit to this journal. No funding received for this cross-sectional study. Authors have no competing interest to declare. All the authors are responsible for the originality of this study. Original data can be shared from first author, if necessary, after a reasonable request. . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this preprint this version posted June 4, 2021. ; https://doi.org/10.1101/2021.06.02.21258242 doi: medRxiv preprint . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this preprint this version posted June 4, 2021. . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this preprint this version posted June 4, 2021. . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this preprint this version posted June 4, 2021. ; https://doi.org/10.1101/2021.06.02.21258242 doi: medRxiv preprint . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review) The copyright holder for this preprint this version posted June 4, 2021. ; https://doi.org/10.1101/2021.06.02.21258242 doi: medRxiv preprint Safety and efficacy of the ChAdOx1 nCoV-19 vaccine (AZD1222) against SARS-CoV-2: an interim analysis of four randomised controlled trials in Brazil, South Africa, and the UK Bharat Biotech Announces Phase 3 Results of COVAXIN®: India's First COVID-19 Vaccine Demonstrates Interim Clinical Efficacy of 81%. covaxin-phase3-efficacy-results.pdf (bharatbiotech.com). Accessed on Antibody Response after First-dose of CovishieldTM®) and BBV-152 (CovaxinTM®) amongst Health Care Workers in India: Preliminary Results of Cross-sectional Coronavirus Vaccineinduced Antibody Titre (COVAT) study. medRxiv preprint doi BMI-body mass index, T2DM-type 2 diabetes mellitus, HTN-hypertension, RAAS-Renin angiotensin aldosterone system, CCB-calcium channel blocker, IHD-ischemic heart disease test or Kruskal-Wallis test, BMI-body mass index, T2DM-type 2 diabetes mellitus, HTN-hypertension, RAAS-Renin angiotensin aldosterone system, CCB-calcium channel blocker, IHD-ischemic heart disease Monotherapy, n (%) Combination therapy, n (%) Insulin, n (%) No