TY - JOUR
T1 - Immune escape and waning immunity of COVID-19 monovalent mRNA vaccines against symptomatic infection with BA.1/BA.2 and BA.5 in Japan
AU - Arashiro, Takeshi
AU - Arima, Yuzo
AU - Kuramochi, Jin
AU - Muraoka, Hirokazu
AU - Sato, Akihiro
AU - Chubachi, Kumi
AU - Oba, Kunihiro
AU - Yanai, Atsushi
AU - Arioka, Hiroko
AU - Uehara, Yuki
AU - Ihara, Genei
AU - Kato, Yasuyuki
AU - Yanagisawa, Naoki
AU - Nagura, Yoshito
AU - Yanai, Hideki
AU - Ueda, Akihiro
AU - Numata, Akira
AU - Kato, Hideaki
AU - Oka, Hideaki
AU - Nishida, Yusuke
AU - Ishii, Koji
AU - Ooki, Takao
AU - Nidaira, Yuki
AU - Asami, Takahiro
AU - Jinta, Torahiko
AU - Nakamura, Akira
AU - Taniyama, Daisuke
AU - Yamamoto, Kei
AU - Tanaka, Katsushi
AU - Ueshima, Kankuro
AU - Fuwa, Tetsuji
AU - Stucky, Ashley
AU - Suzuki, Tadaki
AU - Smith, Chris
AU - Hibberd, Martin
AU - Ariyoshi, Koya
AU - Suzuki, Motoi
N1 - Publisher Copyright:
© 2023 The Author(s)
PY - 2023/11/13
Y1 - 2023/11/13
N2 - Background: Repeated emergence of variants with immune escape capacity and waning immunity from vaccination are major concerns for COVID-19. We examined whether the surge in Omicron subvariant BA.5 cases was due to immune escape or waning immunity through vaccine effectiveness (VE) evaluation. Methods: A test-negative case-control study was conducted in 16 clinics/hospitals during the BA.1/BA.2-dominant and BA.5-dominant periods. VE against symptomatic infection was estimated after adjusting for age, sex, comorbidity, occupation, testing frequency, prior infection, close contact history, clinic/hospital, week, and preventive measures. Absolute VE (aVE) was calculated for 2/3/4 doses, compared to the unvaccinated. Relative VE (rVE) was calculated, comparing 3 vs 2 and 4 vs 3 doses. Results: 13,025 individuals were tested during the BA.1/BA.2-dominant and BA.5-dominant periods with similar baseline characteristics. For BA.1/BA.2, aVE was 52 % (95 %CI:34–66) 14 days-3 months post-dose 2, 42 % (29–52) > 6 months post-dose 2, 71 % (64–77) 14 days-3 months post-dose 3, and 68 % (52–79) 3–6 months post-dose 3. rVE was 49 % (38–57) 14 days-3 months post-dose 3 and 45 % (18–63) 3–6 months post-dose 3. For BA.5, aVE was 56 % (27–73) 3–6 months post-dose 2, 32 % (12–47) > 6 months post-dose 2, 70 % (61–78) 14 days-3 months post-dose 3, 59 % (48–68) 3–6 months post-dose 3, 50 % (29–64) > 6 months post-dose 3, and 74 % (61–83) ≥ 14 days post-dose 4. rVE was 56 % (45–65) 14 days-3 months post-dose 3, 39 % (27–48) 3–6 months post-dose 3, 25 % (-2–45) > 6 months post-dose 3, and 30 % (-6–54) ≥ 14 days post-dose 4. Conclusions: Booster doses initially provided high protection against BA.5 at a level similar to that against BA.1/BA.2. However, the protection seemed shorter-lasting against BA.5, which likely contributed to the surge. Furthermore, rVE post-dose 4 was low even among recent vaccinees. These results support the introduction of variant-containing vaccines and emphasize the need for vaccines with longer duration of protection.
AB - Background: Repeated emergence of variants with immune escape capacity and waning immunity from vaccination are major concerns for COVID-19. We examined whether the surge in Omicron subvariant BA.5 cases was due to immune escape or waning immunity through vaccine effectiveness (VE) evaluation. Methods: A test-negative case-control study was conducted in 16 clinics/hospitals during the BA.1/BA.2-dominant and BA.5-dominant periods. VE against symptomatic infection was estimated after adjusting for age, sex, comorbidity, occupation, testing frequency, prior infection, close contact history, clinic/hospital, week, and preventive measures. Absolute VE (aVE) was calculated for 2/3/4 doses, compared to the unvaccinated. Relative VE (rVE) was calculated, comparing 3 vs 2 and 4 vs 3 doses. Results: 13,025 individuals were tested during the BA.1/BA.2-dominant and BA.5-dominant periods with similar baseline characteristics. For BA.1/BA.2, aVE was 52 % (95 %CI:34–66) 14 days-3 months post-dose 2, 42 % (29–52) > 6 months post-dose 2, 71 % (64–77) 14 days-3 months post-dose 3, and 68 % (52–79) 3–6 months post-dose 3. rVE was 49 % (38–57) 14 days-3 months post-dose 3 and 45 % (18–63) 3–6 months post-dose 3. For BA.5, aVE was 56 % (27–73) 3–6 months post-dose 2, 32 % (12–47) > 6 months post-dose 2, 70 % (61–78) 14 days-3 months post-dose 3, 59 % (48–68) 3–6 months post-dose 3, 50 % (29–64) > 6 months post-dose 3, and 74 % (61–83) ≥ 14 days post-dose 4. rVE was 56 % (45–65) 14 days-3 months post-dose 3, 39 % (27–48) 3–6 months post-dose 3, 25 % (-2–45) > 6 months post-dose 3, and 30 % (-6–54) ≥ 14 days post-dose 4. Conclusions: Booster doses initially provided high protection against BA.5 at a level similar to that against BA.1/BA.2. However, the protection seemed shorter-lasting against BA.5, which likely contributed to the surge. Furthermore, rVE post-dose 4 was low even among recent vaccinees. These results support the introduction of variant-containing vaccines and emphasize the need for vaccines with longer duration of protection.
KW - Coronavirus disease 2019 (COVID-19)
KW - SARS-CoV-2 variants
KW - Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)
KW - Test-negative design
KW - Vaccine effectiveness
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U2 - 10.1016/j.vaccine.2023.10.021
DO - 10.1016/j.vaccine.2023.10.021
M3 - Article
C2 - 37839947
AN - SCOPUS:85173988601
SN - 0264-410X
VL - 41
SP - 6969
EP - 6979
JO - Vaccine
JF - Vaccine
IS - 47
ER -