References:
1. Seekircher L, Bánki Z, Kimpel J, et al. Immune response after two
doses of the BNT162b2 COVID-19 vaccine and risk of SARS-CoV-2
breakthrough infection in Tyrol, Austria: an open-label, observational
phase 4 trial. The Lancet Microbe 2023.
2. Nilles EJ, Paulino CT, De St Aubin M, et al. Tracking immune
correlates of protection for emerging SARS-CoV-2 variants. The
Lancet Infectious Diseases 2023; 23 (2): 153-4.
3. Khoury DS, Cromer D, Reynaldi A, et al. Neutralizing antibody levels
are highly predictive of immune protection from symptomatic SARS-CoV-2
infection. Nat Med 2021; 27 (7): 1205-11.
4. Carr EJ, Wu MY, Gahir J, et al. Neutralising immunity to omicron
sublineages BQ.1.1, XBB, and XBB.1.5 in healthy adults is boosted by
bivalent BA.1-containing mRNA vaccination and previous Omicron
infection. Lancet Infect Dis 2023.
5. Wherry EJ, Barouch DH. T cell immunity to COVID-19 vaccines.Science 2022; 377 (6608): 821-2.
6. Tarke A, Coelho CH, Zhang Z, et al. SARS-CoV-2 vaccination induces
immunological T cell memory able to cross-recognize variants from Alpha
to Omicron. Cell 2022; 185 (5): 847-59 e11.
7. Tan NH, Geers D, Sablerolles RSG, et al. Immunogenicity of bivalent
omicron (BA.1) booster vaccination after different priming regimens in
health-care workers in the Netherlands (SWITCH ON): results from the
direct boost group of an open-label, multicentre, randomised controlled
trial. Lancet Infect Dis 2023.
8. Bayart JL, Douxfils J, Gillot C, et al. Waning of IgG, Total and
Neutralizing Antibodies 6 Months Post-Vaccination with BNT162b2 in
Healthcare Workers. Vaccines (Basel) 2021; 9 (10).
9. Favresse J, Gillot C, Bayart JL, et al. Vaccine-induced binding and
neutralizing antibodies against Omicron 6 months after a homologous
BNT162b2 booster. J Med Virol 2023; 95 (1): e28164.
10. Lin DY, Xu Y, Gu Y, Zeng D, Sunny SK, Moore Z. Durability of
Bivalent Boosters against Omicron Subvariants. N Engl J Med 2023;388 (19): 1818-20.
Figure 1: (A) Evolution of neutralizing antibodies against the
BA.5 omicron variant before and after the bivalent booster with a
6‐month follow‐up in a population of 51 healthy-volunteers. GMT were 157
(95% CI: 112–219), 598 (470–761), 1,095 (903–1,327), 106
(83.4–134), and 47.4 (36.6–61.6) at baseline and after 14, 28, 90, and
180 days. (B ) Kinetic models of the neutralizing capacity
against the BA.5 omicron variant. (C ) Comparison of the
neutralizing capacity against the D614G strain, the delta and BA.5
omicron variants, and the XBB.1.5 omicron subvariant in a population of
30 healthy-volunteers 6 months after having received the bivalent
booster. GMT were 319 (95% CI: 241–423), 162 (119–220), 61.4
(42.7–88.2), and 29.5 (21.4–40.6) for the D614G strain, the delta
variant, the BA.5 omicron variant, and the XBB.1.5 omicron subvariant.
The dotted line represents the positivity cut‐off for neutralizing
antibodies (dilution titer of 1:20). (D ) Evolution of the
cellular response by means of the measurement of IFNγ. GMT were 0.53
UI/mL (95% CI: 0.37–0.75), 0.95 (0.72–1.24), 0.87 (0.65–1.17), 0.65
(0.48–0.87), and 0.52 (0.34–0.79) at baseline and after 14, 28, 90,
and 180 days. The positivity cut‐off for IFNγ was 0.013 IU/mL. Geometric
means and 95% CIs are represented. Only p values <0.05 were
graphically represented.