New study shows booster dose of Novovax NVX-CoV2373 vaccine effective against SARS-CoV-2 Omicron subvariants

The newest analysis is revealed Study Area* A preprint server evaluated neutralizing antibody titers against extreme acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant and its sub-lines after two and three doses of Novovax protein nanoparticle vaccine NVX-CoV2373.

Research: Novavax NVX-COV2373 exerts potent neutralization of Omicron sub-lines. Image credit score: Benjamin Poturak / Shutterstock


Emerging SARS-CoV-2 Omicron subvariants carry a number of mutations within the spike protein area that improve their immune evasion talents, permitting the subvariants to evade neutralizing antibodies induced by vaccines and former SARS-CoV-2 infections. Omicron subvariants BA.4 and BA.5 predominate globally and confer resistance to most vaccines.

However, booster doses with reporter ribonucleic acid (mRNA) vaccines confirmed some neutralizing exercise against these Omicron subvariants. In addition, section III trials with the NVX-CoV2373 protein nanoparticle vaccine had been discovered to be 90% effective against symptomatic infections and 100% effective against extreme coronavirus illness 2019 (COVID-19). This protein nanoparticle vaccine has the added benefit of improved stability and decreased chilly chain necessities. However, the efficacy of booster doses of NVX-CoV2373 vaccine against Omicron BA.4/BA.5 and different subvariants stays unexplored.

About studying

In this study, serum samples had been collected from individuals in South Africa who acquired two or three doses of the Novovax NVX-CoV2373 vaccine. Samples had been collected 14 and 35 days after the second and third doses, respectively. The researchers additionally chosen individuals vaccinated with two doses of the AD26.COV2.S adenoviral vector vaccine or two and three doses of the BNT162b22 mRNA vaccine.

Pseudoviruses containing the ancestral pressure (D614G) and the Beta and Omicron BA.1 variants, in addition to the firefly luciferase gene and spike mutation for the BA.4 and BA.5 subvariants, had been used to check the neutralization effectivity of NVX-CoccV237. – induced antibodies. Modified 293T/ACE2. MF cells overexpressing human angiotensin-converting enzyme-2 (ACE-2) had been used to check the neutralizing efficacy.


The outcomes confirmed that geometric imply titers (GMT) against the D614G pressure peaked at 1401 two weeks after the second NVX-CoV2373 vaccine. Neutralization titers confirmed an 8.1-fold lower against the Beta variant of GMT 173. Neutralization titers against the Omicron BA.1 variant and BA.4/BA.5 subvariants had been 41 and 30 instances decrease, with GMT values ​​of 34 and 47, respectively. 59% of samples against subvariants had been beneath the detection restrict.

However, neutralization titers measured one month after the booster (third) dose of NVX-CoV2373 had been considerably larger in comparison with Omicron BA.1 and BA.4/BA.5 subvariants.

Neutralization titers against the ancestral D614G pressure elevated to 10862 GMT, whereas titers against Beta, Omicron BA.1, and Omicron BA.4/BA.5 elevated to 1733, 1197, and 582 GMT values, 10-, 35-, and 12-fold, respectively. -indicate the increments. However, the titers of Beta, Omicron BA.1, and Omicron BA.4/BA.5 had been nonetheless six to 18 instances decrease than the parental pressure.

In comparability, two doses of the AD26.COV2.S adenoviral vector vaccine confirmed considerably decrease neutralization titers than three doses of the NVX-CoV2373 vaccine or the BNT162b22 mRNA vaccine. GMT values ​​against Omicron BA.1 had been 10- and 14-fold decrease in topics vaccinated with two doses of AD26.COV2.S than these vaccinated with three doses of NVX-CoV2373 and BNT162b22. Against the BA.4/BA.5 subvariants, AD26.COV2.S has 11- and 12-fold decrease neutralizing titers induced by NVX-CoV2373 and BNT162b22, respectively.

Furthermore, all plasma samples from people with three doses of NVX-CoV2373 or BNT162b22 vaccine confirmed neutralizing exercise against Omicron BA.1 and BA.4/BA.5 subvariants, whereas solely 13% to 50% of plasma samples from people AD26.COV2.S confirmed neutralizing exercise against Omicron subvariants with two doses.


In conclusion, on this study, a bunch of researchers from South Africa evaluated the neutralization titers generated against the ancestral SARS-CoV-2 pressure, the Beta and Omicron BA.1 variants, and the BA.4/BA.5 Omicron subvariants. NVX-CoV2373 in people vaccinated with three doses of protein nanoparticle vaccine. They additionally in contrast neutralizing titers with titers induced by two doses of AD26.COV2.S adenoviral vector vaccine or three doses of BNT162b22 mRNA vaccine against Omicron BA.1 and BA.4/BA.5.

The outcomes confirmed that two doses of NVX-CoV2373 vaccine considerably decreased neutralizing titers against Beta, Omicron BA.1 and Omicron BA.4/BA.5 in comparison with the ancestral D614G pressure. vaccine considerably elevated GMT values ​​against all variants examined. Three doses of BNT162b22 vaccine confirmed comparable outcomes, however two doses of AD26.COV2.S didn’t present ample safety against Omicron subvariants.

*Important be aware

Research Square publishes non-peer-reviewed preliminary scientific studies and, subsequently, shouldn’t be thought of conclusive, medical follow/health-related habits steering or prescribed info.


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