Hybrid immunity from SARS-CoV-2 infection and mRNA BNT162b2 vaccine among Thai school-aged children
Kanchanok Saraban,
Piyarat Suntarattiwong,
Napaporn Chantasrisawad,
Sophida Boonsathorn,
Pope Kosalaraksa,
Wanatpreeya Phongsamart,
Auchara Tangsathapornpong,
Peera Jaruampornpan,
Suchada Srisarang,
Thanyawee Puthanakit
Affiliations
Kanchanok Saraban
Queen Sirikit National Institute of Child Health, Bangkok, Thailand; Corresponding author at: Division of Infectious Diseases, Queen Sirikit National Institute of Child Health, Department of Medical Services, Ministry of Public Health, 420/8 Rajavithi Road, Rajatevee, Bangkok 14000, Thailand.
Piyarat Suntarattiwong
Queen Sirikit National Institute of Child Health, Bangkok, Thailand
Napaporn Chantasrisawad
Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand; Center of Excellence for Pediatric Infectious Diseases and Vaccines, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand; Thai Red Cross Emerging Infectious Diseases Clinical Center, King Chulalongkorn Memorial Hospital, Bangkok, Thailand
Sophida Boonsathorn
Department of Pediatrics, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
Pope Kosalaraksa
Pediatric Infectious Disease Unit, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
Wanatpreeya Phongsamart
Division of Infectious Diseases, Department of Pediatrics, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
Auchara Tangsathapornpong
Division of Infectious Diseases, Department of Pediatrics, Faculty of Medicine, Thammasat University, Pathum Thani, Thailand
Peera Jaruampornpan
Virology and Cell Technology Research Team, National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), Pathum Thani, Thailand
Suchada Srisarang
Queen Sirikit National Institute of Child Health, Bangkok, Thailand
Thanyawee Puthanakit
Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand; Center of Excellence for Pediatric Infectious Diseases and Vaccines, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
Objective: To compare the immune response of hybrid immunity – arising from SARS-CoV-2 infection and mRNA BNT162b2 vaccination – to that of 2-doses of vaccine. Methods: In a subanalysis of BNT162b2 vaccine trial in 5 to 11-year-old children, There were 179 children who had hybrid immunity compared with 134 children with solely 2-dose vaccine. The immunological outcome was a surrogate virus neutralization test (sVNT) against the Omicron strain, BA.1, (%inhibition). An sVNT level ≥68 % inhibition was considered as protective immune response. Results: From February to April 2022, 179 children had COVID-19 natural infection resulting in hybrid immunity included: Group1;prior vaccination(n = 17), Group2;after the first dose(n = 61), and Group3;after the second dose(n = 97). The proportion of children with protective immune response was higher in Group 3 and Group 1 – 61.9 % and 58.8 %, compared to 36.1 % and 34.3 % in Group 2 and comparator group (2 doses of vaccine), respectively. The geometric mean % inhibition of sVNT was higher in Group 1 (68.5, 95 %CI 55.5–84.6) and Group 3 (63.5, 95 %CI 55.5–72.6), followed by comparator group (49.6, 95 %CI 44.8–54.9) and Group 2 (42.1, 95 %CI 34.6–51.3), p < 0.001. Conclusions: Immune response that arises from BNT162b2 vaccine after natural infection and infection after 2 doses of BNT162b2 was higher than infection after partially-vaccinated children.
