Booster dose of BNT162b2 after two doses of CoronaVac improves neutralization of SARS-CoV-2 Omicron variant

Abstract

Background The emergence of the new SARS-CoV-2 Omicron variant, which is known to have a large number of mutations when compared to other variants, brought to light the concern about vaccine escape, especially from the neutralization by antibodies induced by vaccination. Methods Based on viral microneutralization assays, we evaluated in 90 individuals the impact on antibody neutralization induction, against Omicron variant, by a booster dose of BNT162b2 mRNA vaccine after the CoronaVac primary vaccination scheme. Results Here we show that the percentage of seroconverted individuals 30 and 60 days after CoronaVac scheme was 16.6% and 10%, respectively. After booster dose administration, the seroconvertion rate increased to 76.6%. The neutralization mean titer against Omicron in the CoronaVac protocol decreased over time, but after the booster dose, the mean titer increased 43.1 times. Conclusions These results indicate a positive impact of this vaccine combination in the serological immune response against SARS-CoV-2 Omicron variant.

Homologous or Heterologous COVID-19 Boosters Regimens Significantly Impact Sero-neutralization of SARS-CoV-2 Virus and Variants

“…Ultimately, in this study, the data show that the use of the BNT162b2 as both first and second booster generated the strongest responses against all strain and variants. An additional dose of BNT162b2 after 2 doses of CoronaVac as the primary vaccination showed a significant increase in the levels of neutralizing antibodies against Omicron in a study conducted in Brazil [18]. Our data support the use of BNT162b2 as a second booster might maintain adequate neutralization against Omicron.…”

Registros de casos acumulados e novos de variantes de preocupação do COVID-19, Brasil, 2021-2022: Ômicron, Gamma e Delta

“…27,28,29 Inicialmente, ela foi considerada enquanto um tipo de variante sob monitoramento (VUM) e, dois (02) dias depois, em 26/11/2021, a OMS declarou a "B.1.529" como uma VOC, com base em evidências de que ela continha inúmeras mutações, influenciando suas características e, também, sendo designada enquanto "Ômicron", ou seja, a décima quinta (15ª) letra do alfabeto grego. 27,28,29,30 A VOC Ômicron, conforme apontado por vários pesquisadores, está agora causando uma rápida disseminação em populações humanas, e ainda, se tornou uma grande preocupação global, mostrando seu significativo potencial de transmissibilidade e consequentemente, de mortalidade. 26,27,28,29,30 Em comparação com outras VOCs, a VOC do tipo Ômicron, tem chamado a atenção, devido ao seu elevado número de mutações em todo do seu genoma, acumulando desta forma, pelo menos quarenta e sete (47) mutações, ou seja, o maior quantitativo entre as variantes conhecidas, das quais, mais da metade, já está presente junto a proteína "Spike", principal alvo da resposta imune sorológica, que é induzida pela maioria das vacinas contra o COVID-19.…”

Mixed formulation of mRNA and protein‐based COVID‐19 vaccines triggered superior neutralizing antibody responses

“…A heterologous prime‐boost immunization strategy, 10 wherein vaccines developed by different technology platforms or antigen sequences are administered sequentially, has been widely studied and proved to be effective in improving the immunogenicity and protection of existing vaccines, including those against HIV, influenza, polio, and hepatitis viruses. 11 , 12 , 13 , 14 , 15 Since nearly all vaccine technologies have been used for COVID‐19 vaccine development, various heterologous prime‐boost regimens, such as mRNA and adenovirus‐vectored vaccines, 16 , 17 , 18 mRNA and inactivated virus vaccines, 19 , 20 adenovirus‐vectored and inactivated virus vaccines, 21 inactivated virus and recombinant protein vaccines, 22 have been investigated in animal models 22 and clinical trials. 16 , 17 , 18 , 19 , 20 , 21 The aforementioned heterologous regimens all showed to be superior or equivalent to a single vaccine regimen in immunogenicity and had a good safety profile.…”

“… 11 , 12 , 13 , 14 , 15 Since nearly all vaccine technologies have been used for COVID‐19 vaccine development, various heterologous prime‐boost regimens, such as mRNA and adenovirus‐vectored vaccines, 16 , 17 , 18 mRNA and inactivated virus vaccines, 19 , 20 adenovirus‐vectored and inactivated virus vaccines, 21 inactivated virus and recombinant protein vaccines, 22 have been investigated in animal models 22 and clinical trials. 16 , 17 , 18 , 19 , 20 , 21 The aforementioned heterologous regimens all showed to be superior or equivalent to a single vaccine regimen in immunogenicity and had a good safety profile. In addition, mixed formulation or co‐delivery of certain COVID‐19 vaccines based on distinct platforms could also elevate the protective immune responses.…”