Encouraging news for your day! A study out of Emory University, Stanford University, and NIAID shows mRNA bivalent boosters ENHANCE neutralization against Omicron subvariants including BA.2.75.2, BQ.1.1, AND XBB! This uses a LIVE virus neutralization assay and IS PEER-REVIEWED!🧵
•Source: nejm.org
NOTE: This study is in regards to NEUTRALIZING ANTIBODY RESPONSES ONLY. YES, there is much more to our immune response than just nAbs. Live neutralization assays tend to be more accurate. Please see below in regards to China AND BF.7.
NOTE: This study is in regards to NEUTRALIZING ANTIBODY RESPONSES ONLY. YES, there is much more to our immune response than just nAbs. Live neutralization assays tend to be more accurate. Please see below in regards to China AND BF.7.
Using a live virus neutralization assay, researchers evaluated serum samples from individuals who had received either one or two monovalent boosters or the bivalent booster to determine neutralizing activity against wild-type (WA1/2020) virus and Omicron subvariants BA.1, BA.5,
BA.2.75.2, and BQ.1.1. In the one monovalent booster cohort, relative to WA1/2020, they observed a reduction in neutralization titers of 9-15-fold against BA.1 and BA.5 and 28-39-fold against BA.2.75.2 and BQ.1.1. In the BA.5-containing bivalent booster cohort, the neutralizing
activity IMPROVED against ALL Omicron subvariants. Relative to WA1/2020, they observed a reduction in neutralization titers of 3.7- and 4-fold against BA.1 and BA.5, respectively, and 11.5- and 21-fold against BA.2.75.2 and BQ.1.1, respectively.
Researchers used an in vitro, live-virus focus neutralization test (FRNT) assay in a VeroE6-TMPRSS2 cell line1 to compare the neutralizing activity of serum from individuals who received one monovalent booster (7-28 days after vaccination), two monovalent boosters (70-100
days after vaccination), or the bivalent booster (16-42 days after vaccination). Fold change in neutralizing antibody response among these three cohorts were quantitated by comparing the FRNT50 GMT (geometric mean titer) values of Omicron against the ancestral SARS-CoV-2 virus.
Samples that fell below the limit of detection (1:20) were given an arbitrary FRNT50 of 10.
In the one monovalent booster cohort, the FRNT50 GMTs were 758 for WA1/2020, 60 for BA.1, 50 for BA.5, 23 for BA.2.75.2 and 19 for BQ.1.1. In the two monovalent booster cohort, the FRNT50
In the one monovalent booster cohort, the FRNT50 GMTs were 758 for WA1/2020, 60 for BA.1, 50 for BA.5, 23 for BA.2.75.2 and 19 for BQ.1.1. In the two monovalent booster cohort, the FRNT50
GMTs were 1812 for WA1/2020, 205 for BA.1, 142 for BA.5, 65 for BA.2.75.2 and 53 for BQ.1.1. In both cohorts, relative to WA1/2020, this corresponded to a reduction in neutralization titers of 9-15 fold against BA.1 and BA.5 and 28-39 fold against BA.2.75.2 and BQ.1.1.
BA.2.75 showed comparable neutralization titers as BA.1 and BA.5 in these cohorts.
In the BA.5-containing bivalent booster cohort, the neutralizing activity improved against all of the Omicron subvariants (Fig 1C). The FRNT50 GMTs were 2312 for WA1/2020, 618 for BA.1, 576
In the BA.5-containing bivalent booster cohort, the neutralizing activity improved against all of the Omicron subvariants (Fig 1C). The FRNT50 GMTs were 2312 for WA1/2020, 618 for BA.1, 576
for BA.5, 201 for BA.2.75.2 and 112 for BQ.1.1. Relative to WA1/2020, this corresponded to a reduction in neutralization titers of 4-fold against BA.1 and BA.5 and 11- and 21- fold against BA.2.75.2 and BQ.1.1, respectively.
The original COVID-19 boosters had a decrease in neutralization activity against Omicron subvariants compared to WA1/2020. This decrease was especially profound for BA.2.75.2 and BQ.1.1, which contain the predicted escape mutation R346T.
Individuals that received the BA.5-containing bivalent booster showed IMPROVED neutralizing activity against ALL Omicron subvariants. These responses are similar to recent observations in individuals with breakthrough Omicron infection showing broadened neutralizing activity
against Omicron variants.
Conclusion: These data demonstrate an overall serological benefit of bivalent booster immunizations and suggest that the bivalent mRNA booster vaccine broadens humoral immunity against all current Omicron subvariants.
Conclusion: These data demonstrate an overall serological benefit of bivalent booster immunizations and suggest that the bivalent mRNA booster vaccine broadens humoral immunity against all current Omicron subvariants.
Loading suggestions...