Abounouh Karima, Tajudeen Raji, Majidi Hind, Redwane Soad, Laazaazia Oumaima, Aqillouch Safaa, Ouma Ahmed E Ogwell, Abdulaziz Mohammed, Aragaw Merawi, Fallah Mosoka Papa, Sembuche Senga, Batcho Serge, Kabwe Patrick, Gonese Elizabeth, Ainahi Abdelhakim, Sarih M'hammed, Kaseya Jean, Maaroufi Abderrahmane, Ezzikouri Sayeh
Virology Unit, Viral Hepatitis Laboratory, Institut Pasteur du Maroc, 1 Place Louis Pasteur, Casablanca, 20360, Morocco.
Africa Centres for Disease Control and Prevention (Africa CDC), African Union, Addis Ababa, Ethiopia.
BMC Infect Dis. 2024 Dec 28;24(1):1470. doi: 10.1186/s12879-024-10345-9.
To assess the impact of the SARS-CoV-2 booster dose on the immune response against COVID-19, we conducted a cross-sectional study in the Casablanca-Settat region of Morocco. The study included 2,802 participants from 16 provinces, all of whom had received three doses of a SARS-CoV-2 vaccine. IgG antibodies targeting the S1 RBD subunit of the SARS-CoV-2 spike protein were quantified using the SARS-CoV-2 IgG II Quant assay and measured on the Abbott Architect i2000SR instrument. Adjusted seroprevalence of anti-RBD antibodies showed that participants who received two doses of ChAdOx1-S followed by a BBIBP-CorV booster had a seroprevalence rate of 99.68% (95% CI: 99.39-99.83%), while those who received a BNT162b2 booster had a rate of 99.67% (95% CI: 99.38-99.82%). Both rates were higher than those observed with other vaccination regimens. The evaluation of booster dose effects revealed significant differences in anti-RBD antibody levels across various vaccination regimens: two doses of BBIBP-CorV compared to three doses of BBIBP-CorV (P < 0.0001), two doses of BNT162b2 versus three doses of BNT162b2 (P = 0.023), two doses of ChAdOx1-S versus two doses of ChAdOx1-S with a BNT162b2 booster (P = 0.023), and two doses of BBIBP-CorV versus two doses of BBIBP-CorV with a BNT162b2 booster (P < 0.0001). However, no significant difference was found between two doses of ChAdOx1-S and three doses of ChAdOx1-S (P = 0.23). Participants with prior SARS-CoV-2 exposure who received two doses of ChAdOx1-S followed by either a BBIBP-CorV or BNT162b2 booster showed higher levels of anti-RBD IgG antibodies (P = 0.042 and P = 0.001, respectively). Interestingly, individuals with comorbidities who received the BNT162b2 booster dose exhibited a significantly stronger humoral response (P < 0.05). In conclusion, our findings highlight the effectiveness of the BNT162b2 booster dose in eliciting a strong immune response. The high seroprevalence rates achieved with both BNT162b2 and BBIBP-CorV boosters reflect the country's robust vaccination strategy.
为评估新型冠状病毒2型（SARS-CoV-2）加强剂量对针对2019冠状病毒病（COVID-19）免疫反应的影响，我们在摩洛哥卡萨布兰卡-塞塔特地区开展了一项横断面研究。该研究纳入了来自16个省份的2802名参与者，他们均已接种三剂SARS-CoV-2疫苗。使用SARS-CoV-2 IgG II定量检测法对靶向SARS-CoV-2刺突蛋白S1受体结合域（RBD）亚单位的IgG抗体进行定量，并在雅培Architect i2000SR仪器上进行检测。抗RBD抗体的校正血清阳性率显示，接种两剂ChAdOx1-S后再接种一剂BBIBP-CorV加强针的参与者血清阳性率为99.68%（95%置信区间：99.39-99.83%），而接种BNT162b2加强针的参与者血清阳性率为99.67%（95%置信区间：99.38-99.82%）。这两个比率均高于其他疫苗接种方案所观察到的比率。加强剂量效果评估显示，不同疫苗接种方案的抗RBD抗体水平存在显著差异：两剂BBIBP-CorV与三剂BBIBP-CorV相比（P＜0.0001），两剂BNT162b2与三剂BNT162b2相比（P = 0.023），两剂ChAdOx1-S与两剂ChAdOx1-S后接种一剂BNT162b2加强针相比（P = 0.023），以及两剂BBIBP-CorV与两剂BBIBP-CorV后接种一剂BNT162b2加强针相比（P＜0.0001）。然而，两剂ChAdOx1-S与三剂ChAdOx1-S之间未发现显著差异（P = 0.23）。先前接触过SARS-CoV-2的参与者接种两剂ChAdOx1-S后再接种一剂BBIBP-CorV或BNT162b2加强针，其抗RBD IgG抗体水平较高（分别为P = 0.042和P = 0.001）。有趣的是，患有合并症的个体接种BNT162b2加强针后表现出显著更强的体液免疫反应（P＜0.05）。总之，我们的研究结果突出了BNT162b2加强针在引发强烈免疫反应方面的有效性。BNT162b2和BBIBP-CorV加强针所达到的高血清阳性率反映了该国强有力的疫苗接种策略。
