Effectiveness of first and second boost COVID-19 vaccination in healthy adults during BA.5.2/BF.7 surge in China

Figures & data

Figure 1. The daily COVID-19 cases, vaccine doses, and SARS-CoV-2 lineages prevalence in China.

(a) The daily COVID-19 cases and vaccine doses in China from 2021 to 2023. Dark shadows indicate the time frame of this study. (b) SARS-CoV-2 PANGO lineage prevalence in China during late 2022 surge. Prevalence was smoothed using a seven-day moving average. The data of cases and vaccine doses were sourced from the Our World in Data COVID-19 dataset (https://ourworldindata.org/coronavirus). The daily prevalence of SARS-CoV-2 PANGO lineages was sourced from GISAID (https://www.epicov.org).

Table 1. Characteristics of the participants.

Characteristics	Prime vaccination (N = 57)	Any boost vaccination (N = 680)	1st boost vaccination (N = 627)	2nd boost vaccination (N = 53)
Age (median, Q1-Q3)	35 (29–40)	37 (31–45)	37 (31–45)	37 (30–41)
Male (n, %)	43 (75.44)	507 (74.56)	464 (74.00)	43 (81.13)
Blood type (n, %)
A	10 (17.54)	207 (30.44)	192 (30.62)	15 (28.3)
B	15 (26.32)	159 (23.38)	147 (23.44)	12 (22.64)
AB	2 (3.51)	55 (8.09)	49 (7.81)	6 (11.32)
O	30 (52.63)	259 (38.09)	239 (38.12)	20 (37.74)
Education (n, %)
Primary school	0 (0)	2 (0.29)	2 (0.32)	0 (0)
Junior high school	5 (8.77)	49 (7.21)	48 (7.66)	1 (1.89)
Senior high school	4 (7.02)	59 (8.68)	56 (8.93)	3 (5.66)
Technical secondary school	4 (7.02)	41 (6.03)	37 (5.90)	4 (7.55)
Junior college	13 (22.81)	143 (21.03)	133 (21.21)	10 (18.87)
Undergraduate	28 (49.12)	336 (49.41)	308 (49.12)	28 (52.83)
Postgraduate	2 (3.51)	46 (6.76)	39 (6.22)	7 (13.21)
Others	1 (1.75)	4 (0.59)	4 (0.64)	0 (0)
Days after the final vaccination (median, Q1-Q3)^a	520 (494–557) (494–557)	371 (317–423)	379 (332–425)	18 (11–32)

^aFor infected and uninfected individuals, the interval from the date of the final dose to the infection date and the investigation date, respectively. Q1, first quartile. Q3, third quartile.

Table 2. Incidence of outcomes and symptoms in participants receiving different vaccination regimens.

Groups	Prime vaccination	Any boost vaccination	1st boost vaccination	2nd boost vaccination
All participants
N	57	680	627	53
Outcomes (n, %)
SARS-CoV-2 infection	46 (8.70)	458 (67.35)	435 (69.38)	23 (43.40)
Symptomatic infection	45 (78.95)	425 (62.50)	404 (64.43)	21 (39.62)
Symptom duration ≥5 days	21 (36.84)	140 (20.59)	134 (21.37)	6 (11.32)
Infection with fever	33 (57.89)	349 (51.32)	335 (53.43)	14 (26.42)
Participants with symptomatic infection
N	45	425	404	21
Symptoms (n, %)
Dizziness	15 (33.33)	52 (12.24)	48 (11.88)	4 (19.05)
Joint pain	11 (24.44)	61 (14.35)	56 (13.86)	5 (23.81)
Nasal congestion or runny nose	16 (35.56)	89 (20.94)	83 (20.54)	6 (28.57)
Gastrointestinal symptom	2 (4.44)	13 (3.06)	12 (2.97)	1 (4.76)
Fatigue	19 (42.22)	129 (30.35)	120 (29.70)	9 (42.86)
Smell or taste disorder	6 (13.33)	45 (10.59)	43 (10.64)	2 (9.52)
Myalgia	15 (33.33)	115 (27.06)	112 (27.72)	3 (14.29)
Headache	13 (28.89)	106 (24.94)	101 (25.00)	5 (23.81)
Fever >39.1°C	7 (15.56)	64 (15.06)	61 (15.10)	3 (14.29)
Cough	22 (48.89)	226 (53.18)	215 (53.22)	11 (52.38)
Fever >38.1°C	21 (46.67)	220 (51.76)	212 (52.48)	8 (38.10)
Any fever	33 (73.33)	348 (81.88)	334 (82.67)	14 (66.67)
Sore throat	13 (28.89)	154 (36.24)	146 (36.14)	8 (38.10)

Figure 2. Effectiveness of various vaccination regimens in preventing different SARS-CoV-2 infections.

The model was adjusted for age, gender, blood type, and education level. Any boost refers to participants who received any number of COVID-19 boost shots. Prime refers to participants who only received prime vaccination. The 1st and 2nd boost refers to participants who received 1 and 2 COVID-19 boost shots, respectively. rVE, vaccine effectiveness.

Figure 3. Effectiveness of various vaccination regimens in reducing symptoms.

The model was adjusted for age, gender, and blood type. Any boost refers to participants who received any number of COVID-19 boost shots. Prime refers to participants who only received prime vaccination. The 1st and 2nd boost refers to participants who received 1 and 2 COVID-19 boost shots, respectively. HR, hazard ratio.

Data availability statement

The data that support this study are available from the corresponding authors upon request. The Date used for showing the daily COVID-19 cases and vaccine doses in China is available from the Our World in Data COVID-19 dataset (https://ourworldindata.org/coronavirus). The daily prevalence of SARS-CoV-2 PANGO lineages is available from GISAID (https://www.epicov.org).