less neutralization, but still waterproof

As the acute respiratory syndrome coronavirus 2 (SARS-CoV-2) progresses, a number of viral changes have been manifested by mutations in the structural and non-structural proteins. The SARS-CoV-2 spike protein binds to the host receptor angiotensin-converting enzyme 2 (ACE2), enabling viral entry into the host cell. Studies have shown many mutations in the spike protein over the past twelve months.

The first significant spike protein differentiation was demonstrated by a mutation from aspartic acid (D) to glycine (G) at position 614, leading to increased viral fitness, reproduction, and binding to ACE2 and intra-conformal changes. the protein. Several other changes have emerged in recent months, raising concerns about changes in transmission, the nature of the disease, and viral fitness.

When SARS-CoV-2 affects humans, our immune system quickly responds against the viral spike protein. The receptor binding motif in the spike protein interacts with the ACE2 receptor and is a major target of neutralization for antibodies. Longitudinal studies have found that the antibodies to the spike protein can remain in the body for at least a year after infection.

The mRNA-1273 vaccine encodes the spike protein SARS-CoV-2 and stimulates a strong neutral immune response to the virus that lasts several months. The variant B.1.351 originated in South Africa with three mutations in the receptor binding domain and many other mutations in the spike protein, all of which can affect viral binding to the ACE2 receptor and strain against neutralization with antibodies.

Comparing antibody binding and viral neutralization against two SARS-CoV-2 variants

Researchers from the USA recently compared antibody binding and viral neutralization against 2 SARS-CoV-2 differences that have emerged in different parts of the world. The researchers used sera from vaccine mRNA spike and people with natural disease against circulating B.1 variant and the emerging B.1.351 variant. The review is published on the preprint server bioRxiv*.

EHC-083E (variant B.1) belongs to PANGO line B.1 and was separated in March 2020 from a nasopharyngeal swab of a patient in Atlanta, GA. This variant is a mutation of D614G in the viral spike protein. Variant B.1.351 was separated in November 2020 from an oropharyngeal swab of a patient in KwaZulu-Natal, South Africa. This variant of the virus induces amino acid mutations (L18F, D80A, D215G) within viral spike proteins and eliminates at 242-244 (L242del, A243del, and L244del) positions, K417N, E484K , N501Y, and D614G.

Neutral antibodies are produced for B.1.351 conversion early in the disease stage

The researchers monitored the reduction of antibody binding to receptor binding derivatives derived from B.1.351 of SARS-CoV-2 spike protein and neutralizing power against the B.1.351 mutation in sera from both humans. individual and vaccine. Their long-term COVID-19 cohort evaluated the effect of antibody binding to the receptor binding domain and neutralization over the SARS-CoV-2 variants. Interestingly, the majority of COVID-19 individuals showed less of an effect on neutralization against the B.1.351 version at later times after infection. This showed that neutralizing antibodies for the B.1.351 version are secreted early during infection and last for several months.

The majority of people with SARS-CoV-2 infection showed binding and neutral titers against the B.1.351 difference in both a hungry and reconstituted serum

According to the observations, the majority of sera samples from acute and convalescent COVID-19 individuals showed antibody binding to B.1.351-dervied receptor binding domain. Most samples also showed a neutral potential for the B.1.351 variable, and the influencing actions of these neutral antibodies may contribute to the control of SARS-CoV-2 infection.

To summarize, although reduced by a few folds, the majority of people with SARS-CoV-2 infection showed binding and neutral titers against the B.1.351 version in hungry sera as well as convalescent seva. In addition, all mRNA-1273 vaccines still maintained viral neutralization. These findings agree with previous observations that natural immunity and vaccine-induced immunity may provide protection against COVID-19 in the context of the SARS-CoV-2 B.1.351 variant.

“Our results show that, despite very little compound reduction, the majority of people with connective and neutral titers showed disease against the B.1.351 difference in starvation and next year. -inforcement, and in addition, all mRNA-1273 vaccines maintained neutralization. ”

* Important message

bioRxiv publish preliminary scientific reports that are not peer-reviewed and, therefore, should not be seen as final, guiding health-related clinical practice / behavior, or be treated as information established.