npj Vaccines (Mar 2023)

Booster vaccination with Ad26.COV2.S or an Omicron-adapted vaccine in pre-immune hamsters protects against Omicron BA.2

  • Maarten Swart,
  • Joan van der Lubbe,
  • Sonja Schmit-Tillemans,
  • Ella van Huizen,
  • Johan Verspuij,
  • Ana Izquierdo Gil,
  • Ying Choi,
  • Chenandly Daal,
  • Aditya Perkasa,
  • Adriaan de Wilde,
  • Erwin Claassen,
  • Rineke de Jong,
  • Katrin E. Wiese,
  • Lisette Cornelissen,
  • Marieke van Es,
  • Marjolein van Heerden,
  • Eleni Kourkouta,
  • Issam Tahiri,
  • Michel Mulders,
  • Jessica Vreugdenhil,
  • Karin Feddes - de Boer,
  • Leacky Muchene,
  • Jeroen Tolboom,
  • Liesbeth Dekking,
  • Jarek Juraszek,
  • Jort Vellinga,
  • Jerome Custers,
  • Rinke Bos,
  • Hanneke Schuitemaker,
  • Frank Wegmann,
  • Ramon Roozendaal,
  • Harmjan Kuipers,
  • Roland Zahn

DOI
https://doi.org/10.1038/s41541-023-00633-x
Journal volume & issue
Vol. 8, no. 1
pp. 1 – 12

Abstract

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Abstract Since the original outbreak of the SARS-CoV-2 virus, several rapidly spreading SARS-CoV-2 variants of concern (VOC) have emerged. Here, we show that a single dose of Ad26.COV2.S (based on the Wuhan-Hu-1 spike variant) protects against the Gamma and Delta variants in naive hamsters, supporting the observed maintained vaccine efficacy in humans against these VOC. Adapted spike-based booster vaccines targeting Omicron variants have now been authorized in the absence of human efficacy data. We evaluated the immunogenicity and efficacy of Ad26.COV2.S.529 (encoding a stabilized Omicron BA.1 spike) in naive mice and in hamsters with pre-existing immunity to the Wuhan-Hu-1 spike. In naive mice, Ad26.COV2.S.529 elicited higher neutralizing antibody titers against SARS-CoV-2 Omicron BA.1 and BA.2, compared with Ad26.COV2.S. However, neutralizing titers against the SARS-CoV-2 B.1 (D614G) and Delta variants were lower after primary vaccination with Ad26.COV2.S.529 compared with Ad26.COV2.S. In contrast, we found comparable Omicron BA.1 and BA.2 neutralizing titers in hamsters with pre-existing Wuhan-Hu-1 spike immunity after vaccination with Ad26.COV2.S, Ad26.COV2.S.529 or a combination of the two vaccines. Moreover, all three vaccine modalities induced equivalent protection against Omicron BA.2 challenge in these animals. Overall, our data suggest that an Omicron BA.1-based booster in rodents does not improve immunogenicity and efficacy against Omicron BA.2 over an Ad26.COV2.S booster in a setting of pre-existing immunity to SARS-CoV-2.