Akiko Iwasaki: Thus, CoronaVac recipients may need 2 additional booster doses to reach levels needed against Omicron

Posted on February 9, 2022 by weehingthong

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This is what Pharmaniaga is supposed to have said:

In a statement, Pharmaniaga said the research conducted by Yale University, the Dominican Republic’s Ministry of Health and other institutions, demonstrated that the primary two doses of Sinovac Covid-19 vaccine with the booster shot of Pfizer produced an antibody response similar to a two-dose mRNA vaccine.

The country’s sole distributor of Sinovac vaccine also noted that Yale University School of Medicine Immunobiology Professor Akiko Iwasaki, in her official Twitter account said, “Sinovac Covid-19 vaccine’s two-dose recipients boosted with Pfizer mRNA vax, prior infection made no difference to the neutralisation capacity against Omicron.”

https://www.theedgemarkets.com/article/combination-sinovac-and-pfizer-proven-less-effective-fight-omicron-says-pharmaniaga

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This is Prof Akiko Iwasaki’s actual tweet:

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Immunogenicity of heterologous BNT162b2 booster in fully vaccinated individuals with CoronaVac against SARS-CoV-2 variants Delta and Omicron: the Dominican Republic Experience

Eddy Pérez-Then, View ORCID ProfileCarolina Lucas, Valter Silva Monteiro, Marija Miric, Vivian Brache, Leila Cochon, Chantal B. F. Vogels, Elena De la Cruz, Aidelis Jorge, Margarita De los Santos, Patricia Leon, Mallery I. Breban, Kendall Billig, Inci Yildirim, Claire Pearson, Randy Downing, Emily Gagnon, Anthony Muyombwe, Jafar Razeq, Melissa Campbell, View ORCID ProfileAlbert Ko, Saad B. Omer, Nathan D. Grubaugh, Sten H. Vermund, View ORCID ProfileAkiko Iwasaki

doi: https://doi.org/10.1101/2021.12.27.21268459

This article is a preprint and has not been peer-reviewed [what does this mean?]. It reports new medical research that has yet to be evaluated and so should not be used to guide clinical practice.

Abstract

The recent emergence of the SARS-CoV-2 Omicron variant is raising concerns because of its increased transmissibility and by its numerous spike mutations with potential to evade neutralizing antibodies elicited by COVID-19 vaccines. The Dominican Republic was among the first countries in recommending the administration of a third dose COVID-19 vaccine to address potential waning immunity and reduced effectiveness against variants. Here, we evaluated the effects of a heterologous BNT162b2 mRNA vaccine booster on the humoral immunity of participants that had received a two-dose regimen of CoronaVac, an inactivated vaccine used globally. We found that heterologous CoronaVac prime followed by BNT162b2 booster regimen induces elevated virus-specific antibody levels and potent neutralization activity against the ancestral virus and Delta variant, resembling the titers obtained after two doses of mRNA vaccines. While neutralization of Omicron was undetectable in participants that had received a two-dose regimen of CoronaVac vaccine, BNT162b2 booster resulted in a 1.4-fold increase in neutralization activity against Omicron, compared to two-dose mRNA vaccine. Despite this increase, neutralizing antibody titers were reduced by 6.3-fold and 2.7-fold for Omicron compared to ancestral and Delta variant, respectively. Surprisingly, previous SARS-CoV-2 infection did not affect the neutralizing titers for Omicron in participants that received the heterologous regimen. Our findings have immediate implications for multiples countries that previously used a two-dose regimen of CoronaVac and reinforce the notion that the Omicron variant is associated with immune escape from vaccines or infection-induced immunity, highlighting the global need for vaccine boosters to combat the impact of emerging variants.

https://www.medrxiv.org/content/10.1101/2021.12.27.21268459v1

https://www.medrxiv.org/content/10.1101/2021.12.27.21268459v1

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