Okay Bob. I got through it once at 2.5 hours. In addition to the post I made above here is the entire section in which the snippet you posted is taken. Wherever you got that. I think the entire article is impossible for laypeople to read butyou should get the drift. As I have been saying they do not know. They see a diminished immune response with both repeated infections and vaccinations but they don't know what that means long term or whether variant-specific vaccines will change that.
As additional variants of SARS-CoV-2 appear over time, individuals
will acquire distinct immunological histories depending
on which vaccines they received and which viral variants infected
them. The idea that ‘‘imprinting’’ by a prior antigen exposure
can shape, either positively or negatively, the response to a
subsequent variant is well established in studies of influenza viruses
and has been implicated in birth-year differences in susceptibility
to particular avian influenza viruses (Gostic et al.,
2016). We find that prior vaccination with Wuhan-Hu-1-like antigens
followed by infection with Alpha or Delta variants gives rise
to plasma antibody responses with apparent Wuhan-Hu-1-specific
imprinting manifesting as relatively decreased responses to
the variant virus epitopes, compared with unvaccinated patients
infected with those variant viruses. While current booster vaccinations
are still based on the Wuhan-Hu-1-like antigens, vaccine
manufacturers are in the process of evaluating updated vaccine encoding
sequences from one or more circulating variants.
Initial
results from the third-dose boosting with Beta-spike-encoding
mRNA vaccines after prior second-dose mRNA-1273 vaccination
are consistent with our findings of significant imprinting of
serological responses by the first antigen encountered (Choi
et al., 2021; Chu et al., 2021), indicating that vaccine-derived
imprinting affects subsequent antibody responses stimulated
by vaccination as well as infection. The extent to which vaccine
boosting or infection with different variants will effectively elicit
antibody responses to new epitopes or rather increase responses
to the epitopes of antigens encountered previously,
as in the ‘‘original antigenic sin’’ phenomenon described for influenza
virus infection and vaccination (Arevalo et al., 2020; Zhang
et al., 2019), will be an important topic of ongoing study. T
he degree
of imprinting may depend on the particular variants and the
order in which they are introduced to the individual’s immune
system and the number of exposures, such as the number of
vaccine doses received. Additional data for evaluating the
magnitude of these effects and their consequences for protection
from infection are likely to become available in coming
months, as individuals with different histories of SARS-CoV-2
vaccination or viral variant infection become infected with the
more highly mutated Omicron variant (https://covdb.stanford.
edu/page/mutation-viewer/#omicron).