Safety and immunogenicity of the SARS-CoV-2 BNT162b1 mRNA vaccine in younger and older Chinese adults: a randomized, placebo-controlled, double-blind phase 1 study

Nat Med. 2021 Jun;27(6):1062-1070. doi: 10.1038/s41591-021-01330-9. Epub 2021 Apr 22.


An effective vaccine is needed to end the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. Here, we assess the preliminary safety, tolerability and immunogenicity data from an ongoing single-center (in Jiangsu province, China), parallel-group, double-blind phase 1 trial of the vaccine candidate BNT162b1 in 144 healthy SARS-CoV-2-naive Chinese participants. These participants are randomized 1:1:1 to receive prime and boost vaccinations of 10 µg or 30 µg BNT162b1 or placebo, given 21 d apart, with equal allocation of younger (aged 18-55 years) and older adults (aged 65-85 years) to each treatment group (ChiCTR2000034825). BNT162b1 encodes the SARS-CoV-2 spike glycoprotein receptor-binding domain (RBD) and is one of several messenger RNA-based vaccine candidates under clinical investigation. Local reactions and systemic events were generally dose dependent, transient and mild to moderate. Fever was the only grade 3 adverse event. BNT162b1 induced robust interferon-γ T cell responses to a peptide pool including the RBD in both younger and older Chinese adults, and geometric mean neutralizing titers reached 2.1-fold (for younger participants) and 1.3-fold (for the older participants) that of a panel of COVID-19 convalescent human sera obtained at least 14 d after positive SARS-CoV-2 polymerase chain reaction test. In summary, BNT162b1 has an acceptable safety profile and produces high levels of humoral and T cell responses in an Asian population.

Publication types

  • Clinical Trial, Phase I
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Antibodies, Neutralizing / immunology
  • Antibodies, Neutralizing / therapeutic use
  • Antibodies, Viral / genetics
  • Antibodies, Viral / immunology
  • BNT162 Vaccine
  • COVID-19 / immunology
  • COVID-19 / prevention & control*
  • COVID-19 / virology
  • COVID-19 Vaccines / administration & dosage*
  • COVID-19 Vaccines / adverse effects
  • China / epidemiology
  • Female
  • Humans
  • Male
  • Middle Aged
  • Pandemics
  • RNA, Messenger / genetics
  • RNA, Messenger / immunology
  • SARS-CoV-2 / drug effects
  • SARS-CoV-2 / pathogenicity
  • Spike Glycoprotein, Coronavirus / genetics
  • Spike Glycoprotein, Coronavirus / immunology*
  • Vaccines, Synthetic / administration & dosage
  • Vaccines, Synthetic / genetics
  • Vaccines, Synthetic / immunology*
  • Young Adult


  • Antibodies, Neutralizing
  • Antibodies, Viral
  • COVID-19 Vaccines
  • RNA, Messenger
  • Spike Glycoprotein, Coronavirus
  • Vaccines, Synthetic
  • mRNA Vaccine
  • spike glycoprotein, SARS-CoV
  • BNT162 Vaccine

Associated data

  • ChiCTR/2000034825