Immunogenicity of BNT162b2 in children 6 months to under 5 years of age with previous SARS-CoV-2 infection, in the era of Omicron predominance
Rapisa Nantanee,
Peera Jaru-Ampornpan,
Napaporn Chantasrisawad,
Orawan Himananto,
Supawan Papakhee,
Jiratchaya Sophonphan,
Monta Tawan,
Thidarat Jupimai,
Suvaporn Anugulruengkitt,
Thanyawee Puthanakit
Affiliations
Rapisa Nantanee
Center of Excellence for Pediatric Infectious Diseases and Vaccines, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand; Center of Excellence for Allergy and Clinical Immunology, Division of Allergy, Immunology and Rheumatology, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, King Chulalongkorn Memorial Hospital, the Thai Red Cross Society, Bangkok, Thailand
Peera Jaru-Ampornpan
Virology and Cell Technology Research Team, National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), Pathum Thani, Thailand
Napaporn Chantasrisawad
Division of Infectious Diseases, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand; Thai Red Cross Emerging Infectious Diseases Clinical Center, King Chulalongkorn Memorial Hospital, Bangkok, Thailand
Orawan Himananto
Monoclonal and Antibody Production Research Team, National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), Pathum Thani, Thailand
Supawan Papakhee
Center of Excellence for Pediatric Infectious Diseases and Vaccines, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand; Division of Infectious Diseases, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
Jiratchaya Sophonphan
Center of Excellence for Pediatric Infectious Diseases and Vaccines, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
Monta Tawan
Center of Excellence for Pediatric Infectious Diseases and Vaccines, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
Thidarat Jupimai
Center of Excellence for Pediatric Infectious Diseases and Vaccines, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
Suvaporn Anugulruengkitt
Center of Excellence for Pediatric Infectious Diseases and Vaccines, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand; Division of Infectious Diseases, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
Thanyawee Puthanakit
Center of Excellence for Pediatric Infectious Diseases and Vaccines, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand; Division of Infectious Diseases, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand; Corresponding author at: Center of Excellence for Pediatric Infectious Diseases and Vaccines, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, 1873, Rama IV, Pathumwan, Bangkok 10330, Thailand.
Background: Children 6 months to 6 months(N = 40) prior to vaccination. Participants in Group A and B received 2-dose BNT162b2 intramuscularly 1 month apart. COVID-naïve children were enrolled as a control group (N = 40) and received 3-dose BNT162b2 at month 0,1,3. Neutralizing antibody against Omicron variant(BA.2.75 and BA.4/5) was determined by pseudovirus assays(pVNT) as reported by neutralization dilution for 50%inhibition (ID50) at 28 days after the 1st and 2nd dose. Results: From October-November 2022, 120 children with a median age of 2.8 years (IQR 1.6–4.0) were enrolled. The median duration since COVID-19 to vaccination was 4.4 months(IQR 3.8–5.4) in Group A and 7.9 months(7.0–8.5) in Group B. In Group A, the geometric means(GMs) of pVNT-BA.2.75 ID50 were 553 (95%CI 338–906) and 753(516–1098) after 1 and 2 doses, respectively, and the GMs of pVNT-BA.4/5 ID50 were 1936(1402–2673) and 1885(1414–2512), respectively. In Group B, the GMs of pVNT-BA.2.75 ID50 were 1383(1100–1742) and 1419 (1104–1823), and the GMs of pVNT-BA.4/5 ID50 were 2627(2048–3367) and 2056(1546–2735), respectively. Meanwhile in COVID-naïve group, the GMs of pVNT-BA.2.75 and pVNT-BA.4/5 ID50 were 158(98–255) and 59(31–114) after the 3rd dose, respectively. The geometric mean ratio(GMR) of pVNT-BA.2.75 ID50 after 1 dose in Group A and B compared with after 3 doses in COVID-naïve group were 3.50 (1.93–6.34) and 8.74 (4.79–15.95), respectively. The GMR of pVNT-BA.2.75 ID50 after 1 dose in Group B compared with Group A was 2.50 (1.45–4.31). Conclusions: Children previously infected with SARS-CoV-2 Omicron variant, developed robust neutralizing antibody response against Omicron variant after single-dose BNT162b2. Children with an interval of > 6 months since COVID-19 infection developed higher neutralizing antibody response compared to those with a 3-to-6-month interval.
