Long-Term Results of Immunogenicity of Booster Vaccination against SARS-CoV-2 (Hybrid COV-RAPEL TR Study) in Turkiye: A Double-Blind, Randomized, Controlled, Multicenter Phase 2 Clinical Study
Ihsan Ates,
Ayse Batirel,
Mehtap Aydin,
Fatma Yilmaz Karadag,
Abdulsamet Erden,
Orhan Kucuksahin,
Berkan Armagan,
Serdar Can Guven,
Ozlem Karakas,
Selim Gokdemir,
Lutfiye Nilsun Altunal,
Aslihan Ayse Buber,
Emin Gemcioglu,
Oguzhan Zengin,
Osman Inan,
Enes Seyda Sahiner,
Gulay Korukluoglu,
Zafer Sezer,
Aykut Ozdarendeli,
Ahmet Omma,
Ates Kara
Affiliations
Ihsan Ates
Department of Internal Medicine, University of Health Sciences, Ankara City Hospital, 06800 Ankara, Türkiye
Ayse Batirel
Department of Infectious Diseases and Clinical Microbiology, University of Health Sciences, International Medical School, Kartal Dr. Lutfi Kirdar City Hospital, 34865 Istanbul, Türkiye
Mehtap Aydin
Department of Infectious Diseases and Clinical Microbiology, University of Health Sciences, Umraniye Training and Research Hospital, 34760 Istanbul, Türkiye
Fatma Yilmaz Karadag
Department of Infectious Diseases, University of Health Sciences, Sancaktepe Sehit Prof. Dr. Ilhan Varank Training and Research Hospital, 34785 Istanbul, Türkiye
Abdulsamet Erden
Clinic of Rheumatology, Ankara City Hospital, 06800 Ankara, Türkiye
Orhan Kucuksahin
Clinic of Rheumatology, Ankara City Hospital, 06800 Ankara, Türkiye
Berkan Armagan
Clinic of Rheumatology, Ankara City Hospital, 06800 Ankara, Türkiye
Serdar Can Guven
Clinic of Rheumatology, Ankara City Hospital, 06800 Ankara, Türkiye
Ozlem Karakas
Clinic of Rheumatology, Ankara City Hospital, 06800 Ankara, Türkiye
Selim Gokdemir
Department of Clinical Pharmacology, University of Health Sciences, Kartal Dr. Lutfi Kirdar City Hospital, 34865 Istanbul, Türkiye
Lutfiye Nilsun Altunal
Department of Infectious Diseases and Clinical Microbiology, University of Health Sciences, Umraniye Training and Research Hospital, 34760 Istanbul, Türkiye
Aslihan Ayse Buber
Department of Infectious Diseases, University of Health Sciences, Sancaktepe Sehit Prof. Dr. Ilhan Varank Training and Research Hospital, 34785 Istanbul, Türkiye
Emin Gemcioglu
Department of Internal Medicine, University of Health Sciences, Ankara City Hospital, 06800 Ankara, Türkiye
Oguzhan Zengin
Department of Internal Medicine, University of Health Sciences, Ankara City Hospital, 06800 Ankara, Türkiye
Osman Inan
Department of Internal Medicine, University of Health Sciences, Ankara City Hospital, 06800 Ankara, Türkiye
Enes Seyda Sahiner
Department of Internal Medicine, University of Health Sciences, Ankara City Hospital, 06800 Ankara, Türkiye
Gulay Korukluoglu
Virology Laboratory, General Directorate of Public Health, 06560 Ankara, Türkiye
Zafer Sezer
Department of Pharmacology, Erciyes University, 38030 Kayseri, Türkiye
Aykut Ozdarendeli
Vaccine Research, Development and Application Center, Erciyes University, 38280 Kayseri, Türkiye
Ahmet Omma
Clinic of Rheumatology, University of Health Sciences, Ankara City Hospital, 06800 Ankara, Türkiye
Ates Kara
Division of Pediatric Infectious Diseases, Department of Pediatrics, Hacettepe University, 06230 Ankara, Türkiye
The immunogenicity of vaccines decreases over time, causing a need for booster doses. This study aimed to present the long-term (Day 84) immunogenicity results of the double-blind, randomized, controlled, phase II Hybrid COV-RAPEL TR Study (NCT04979949), in which the TURKOVAC or CoronaVac vaccines were used as a booster after the second dose of primary vaccination with CoronaVac. A total of 190 participants from the Hybrid COV-RAPEL TR Study, who had both Day 28 and Day 84 immunogenicity results, were included. The immunogenicity on Day 84, regarding the neutralizing antibody positivity (Wuhan and Delta variants) and anti-spike immunoglobulin (Ig) G (IgG) antibody positivity, was compared between TURKOVAC and CoronaVac vaccine arms according to sex and age groups. Overall, antibody positivity showed a slight decrease on Day 84 vs. Day 28, but was not different between TURKOVAC and CoronaVac arms either for sexes or for age groups. However, TURKOVAC produced better antibody response against the Delta variant than CoronaVac, while CoronaVac was superior over TURKOVAC regarding neutralizing antibody positivity in the 50–60 years age group, regardless of the variant. A single booster dose, after the completion of the primary vaccination, increases antibody positivity on Day 28 which persists until Day 84 with a slight decrease. However, an additional booster dose may be required thereafter, since the decrease in antibody titer may be faster over time.
