Electronic Theses and Dissertation

Coronavirus disease 2019 (COVID-19) ditemukan pertama kali di Wuhan, Cina, pada Desember 2019. Seiring munculnya varian Delta dan Omicron, tingkat protektif pasca vaksinasi dosis primer mengalami penurunan sehingga diperlukan pemberian dosis booster. Tujuan dari penelitian ini adalah untuk mengetahui titer neutralizing antibody (NAb) anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pada individu pasca vaksinasi booster dengan vaksin COVID-19 berbasis mRNA dan faktor yang mempengaruhinya. Penelitian ini merupakan penelitian analitik observasional dengan desain cross-sectional. Teknik sampling yang digunakan adalah purposive sampling. Jumlah responden penelitian ini sebanyak 158. Darah responden diambil sebanyak 3 cc dan titer NAb diperiksa menggunakan uji kuantitatif enzyme-linked immunosorbent assay (ELISA). Pada penelitian ini sebanyak 86 responden menerima vaksin BNT162b2 dan 72 menerima vaksin mRNA-1273. Median titer NAb anti-SARS-CoV-2 pasca vaksinasi booster adalah 957,73 BAU/mL pada vaksin gabungan (mRNA-1273 dan BNT162b2), 989,41 BAU/mL pada vaksin mRNA-1273 dan 957,73 BAU/mL pada vaksin BNT162b2. Hasil analisis Mann-Whitney dan Kruskal-Wallis menunjukkan tidak ada pengaruh usia (p = 0,295) dan jenis kelamin (p = 0,425) terhadap titer NAb anti-SARS-CoV-2. Analisis multiple regresi linier menunjukkan adanya pengaruh jangka waktu antara vaksinasi booster dengan waktu pemeriksaan antibodi dan indeks massa tubuh (IMT) terhadap titer NAb anti-SARS-CoV-2. Dibandingkan dengan waktu ≤ 3 bulan pasca vaksinasi booster, titer NAb pada kelompok waktu 4–6 bulan pasca vaksinasi booster lebih rendah (p = 0,004), begitu juga pada kelompok waktu 7–9 bulan (p = 0,006), 10–12 bulan (p = 0,005), dan > 12 bulan (p = 0,035) pasca vaksinasi booster. Titer NAb anti-SARS-CoV-2 pada kelompok IMT overweight lebih tinggi dibandingkan dengan kelompok IMT normal (p = 0,007). Hasil uji korelasi Spearman menunjukkan arah korelasi negatif antara waktu pasca vaksinasi booster dengan titer NAb anti-SARS-CoV-2, tetapi tidak signifikan (rs = -0,008; p = 0,919).

Kata kunci: COVID-19, SARS-CoV-2, booster, vaksin mRNA, neutralizing antibody

Coronavirus disease 2019 (COVID-19) was first emerged in Wuhan, China, in December 2019. The emergence of Delta and Omicron variants, the protective level after the primary doses of vaccination was expected sub-optimal and therefore a booster dose is needed. The aim of this study was to measure the neutralizing antibody (NAb) titer of anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in post a booster dose with the COVID-19 mRNA-based vaccine and its associated factors. This study was an analytical observational cross-sectional study using purposive sampling technique. A total of 158 respondents were recruited. Approximately three ml of venous blood were collected from each respondent and the NAb titer was measured using the quantitative enzyme-linked immunosorbent assay (ELISA). Out of total respondents, 86 received the BNT162b2 vaccine and received the mRNA-1273 vaccine. The median of anti-SARS-CoV-2 NAb titer was 957.73 BAU/mL in both of mRNA vaccines (mRNA-1273 and BNT162b2), 989.41 BAU/mL in mRNA-1273 vaccine, and 957.73 BAU/mL in BNT162b2 vaccine. Mann-Whitney and Kruskal-Wallis analyses showed that age (p = 0.295) and gender (p = 0.425) had no association with anti-SARS-CoV-2 NAb titer. Multiple linear regression analysis found that the time interval between booster vaccination and the time of antibody testing, and body mass index (BMI) were associated with NAb titer (R2 = 0.103; F = 2.466; p = 0.020). Compared to ≤ 3-month post-booster vaccination group, the NAb titer in the 4–6 months post-booster vaccination group were lower (p = 0.004), as well as in the 7–9 months (p = 0.006), 10–12 months (p = 0.005), and > 12 months group (p = 0.035). The NAb titer in the overweight group was higher than those in the normal BMI group (p = 0.007). The Spearman rank correlation showed a negative correlation between time interval and anti-SARS-CoV-2 NAb titer, but it was not significant (rs = -0.008; p = 0.919). Keywords: COVID-19, SARS-CoV-2, booster, mRNA vaccine, neutralizing antibody