Vaccines (Mar 2022)

The Pilot Study of Immunogenicity and Adverse Events of a COVID-19 Vaccine Regimen: Priming with Inactivated Whole SARS-CoV-2 Vaccine (CoronaVac) and Boosting with the Adenoviral Vector (ChAdOx1 nCoV-19) Vaccine

  • Surakameth Mahasirimongkol,
  • Athiwat Khunphon,
  • Oraya Kwangsukstid,
  • Sompong Sapsutthipas,
  • Mingkwan Wichaidit,
  • Archawin Rojanawiwat,
  • Nuanjun Wichuckchinda,
  • Wiroj Puangtubtim,
  • Warangluk Pimpapai,
  • Sakulrat Soonthorncharttrawat,
  • Asawin Wanitchang,
  • Anan Jongkaewwattana,
  • Kanjana Srisutthisamphan,
  • Daraka Phainupong,
  • Naphatcha Thawong,
  • Pundharika Piboonsiri,
  • Waritta Sawaengdee,
  • Thitiporn Somsaard,
  • Kanokphon Ritthitham,
  • Supaporn Chumpol,
  • Nadthanan Pinyosukhee,
  • Rattanawadee Wichajarn,
  • Panadda Dhepakson,
  • Sopon Iamsirithaworn,
  • Supaporn Phumiamorn

DOI
https://doi.org/10.3390/vaccines10040536
Journal volume & issue
Vol. 10, no. 4
p. 536

Abstract

Read online

In response to the SARS-CoV-2 Delta variant, which partially escaped the vaccine-induced immunity provided by two doses of vaccination with CoronaVac (Sinovac), the National Vaccine Committee recommended the heterologous CoronaVac-ChAdOx1 (Oxford–AstraZeneca), a prime–boost vaccine regimen. This pilot study aimed to describe the immunogenicity and adverse events of the heterologous CoronaVac-ChAdOx1 regimen, in comparison with homologous CoronaVac, and homologous ChAdOx1. Between May and August 2021, we recruited a total of 354 participants from four vaccination groups: the CoronaVac-ChAdOx1 vaccinee (n = 155), the homologous CoronaVac vaccinee (n = 32), the homologous ChAdOx1 vaccinee (n = 47), and control group of COVID-19 patients (n = 120). Immunogenicity was evaluated by measuring the level of IgG antibodies against the receptor-binding domain (anti-SRBD) of the SARS-CoV-2 spike protein S1 subunit and the level of neutralizing antibodies (NAbs) against variants of concern (VOCs) using the plaque reduction neutralization test (PRNT) and pseudovirus neutralization test (pVNT). The safety profile was recorded by interviewing at the 1-month visit after vaccination. The anti-SRBD level after the second booster dose of the CoronaVac-ChAdOx1 group at 2 weeks was higher than 4 weeks. At 4 weeks after the second booster dose, the anti-SRBD level in the CoronaVac-ChAdOx1 group was significantly higher than either homologous CoronaVac, the homologous ChAdOx1 group, and Control group (p 50 level against the wild-type (434.5 BAU/mL) was the highest; followed by Alpha variant (80.4), Delta variant (67.4), and Beta variant (19.8). The PVNT50 level was also found to be at its highest against the wild-type (432.1); followed by Delta variants (178.3), Alpha variants (163.9), and Beta variant (42.2), respectively. The AEs in the CoronaVac-ChAdOx1 group were well tolerated and generally unremarkable. The CoronaVac-ChAdOx1 heterologous regimen induced higher immunogenicity and a tolerable safety profile. In a situation when only CoronaVac-ChAdOx1 vaccines are available, they should be considered for use in responding to the Delta variant.

Keywords