This real-world study explores the effect of coronavirus disease 2019 (COVID-19) inactivated vaccines on the prevention of asymptomatic or mild Delta or Omicron variant infections progressing to pneumonia. Association between severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pneumonia cases and vaccination was measured with a multivariable logistic regression, stratified by genotype and age groups. We recruited 265 cases (111 (41.9%) infected with Delta and 154 (58.1%) with Omicron variants). There were 22 asymptomatic infected individuals, 156 mild cases without pneumonia, and 87 moderate cases with pneumonia. There was a markedly increased risk of progression to pneumonia in Delta infected cases, unvaccinated, or partially vaccinated COVID-19 patients with diabetes and those aged ≥60 years. Patients who had completed booster doses of inactivated vaccines had a reduced risk of 81.6% (95% CI: 55.6–92.4%) in progressing to pneumonia over those who were unvaccinated or partially vaccinated. The risk of progressing to pneumonia was less reduced by 88.7% (95% CI: 56.6–97%) and 73.9% (95% CI: 1.4–93.1%) among Delta and Omicron-infected patients, and was reduced by 78.5% (95% CI: 45.3–91.6%) and 94.1% (95% CI: 21.5–99.6%) among patients aged <60 and ≥60 years, respectively. Our data indicated that a complete vaccination with a booster reduced the risk of asymptomatic or mild Delta or Omicron variant COVID-19 progressing to pneumonia and, thus, reduced the pressure of severe illness on medical resources.

Hospital-based case control studies have found family history of herpes zoster (HZ) was associated with risk of HZ, but the role of family history is not fully examined for other HZ-associated outcomes such as recurrent HZ, occurrence of postherpetic neuralgia (PHN), and HZ with different pain severities. We conducted a population-based matched case control study. HZ cases that occurred during December 1, 2011 to November 30, 2012 were identified by face-to-face interview with all residents of eight selected communities/villages from three districts of Beijing, China. Medical records were reviewed for those who sought healthcare for HZ. For each case-patient, three, age-matched controls (±5 years) without HZ were enrolled from the same community/village of the matched case. Data on family history of HZ were collected by interview and only defined among first-degree relatives. A total of 227 case-patients and 678 matched controls were enrolled. Case-patients were more likely to report a family history of HZ [odds ratio (OR) =2.4, P = 0.002]. Compared with controls, association of family history decreased from HZ with PHN to HZ without PHN (OR = 6.0 and 2.3, respectively; P = 0.002 for trend), from recurrent HZ to primary HZ (OR = 9.4 and 2.2, respectively; P = 0.005 for trend), and from HZ with moderate or severe pain to HZ with mild or no pain (OR = 3.2 and 0.8, respectively; P < 0.001 for trend). Family history of HZ was associated with HZ occurrence and was more likely in HZ case-patients with PHN, recurrences, and painful HZ.

Numerous post-licensure studies, mostly from field epidemiological evidences such as outbreak surveys, have demonstrated the effectivenesss and insufficiency of one-dose varicella vaccine in outbreak control. Serological evidence of immunization failure is, however, relatively less reported in contrast. A cross-sectional seroepidemiological survey of Beijing residents was performed in 2012 in the People’s Republic of China, after the one-dose varicella vaccine had been widely used for several years. Multistage stratified random sampling method was designed to recruit 2 144 subjects. The ELISA method was used to test the present blood samples collected and the reserve samples collected in 2008 to assess the trends of anti-VZV seroprevalence in the past 5 years and to determine the risk factors for varicella infection. The age- and sex- adjusted overall anti-VZV seropositivity of Beijing residents in 2012 was 84.5 %. Two groups’ adjusted overall anti-VZV seroprevalence in 2012 showed obvious growth compared with 2008 (<1 yr old: from 6.3 % to 16.9 %; 1-4 yr old: from 27.6 % to 57.2 %). Reported one-dose vaccination history was 71.6 % (149/208), 80.9 % (182/225) and 82.2 % (180/219) in the 1-4 yr, 5-9 yr, 10-14 yr age groups, respectively. Of subjects who had received the one-dose vaccine, 36 % (216/603) showed negative anti-VZV concentrations (<110 mIU/mL); additionally 15.9 % (96/603) of such subjects’ anti-VZV concentrations were in the lowest positive concentration group (110-299 mIU/mL). Seropositivity in permanent residents of 1-9 yr old with verified vaccination was merely 61.8 %. Various age groups (1-3 yr, 4-6 yr, and 7-9 yr) all showed seropositivity that gradually decreased with increasing of the interval between vaccination and blood sampling. Mass varicella vaccination significantly improved the immunity of younger Beijing residents. However, vaccine-induced anti-VZV antibody soon became weak in children with high coverage (approximately 80 %) after vaccination for several years which is significantly higher than reported in pre-licensure studies. A government-funded 2-dose immunization program with mandatory vaccination schedule for Beijing residents may need consideration in the near future.

To estimate vaccine effectiveness(VE) against COVID-19-related hospitalization for inactivated vaccines during the Omicron BF.7-predominant epidemic wave in Beijing, China. We recruited a cohort in Beijing on 17 and 18 December 2022, collected status of vaccination and COVID-19-related hospitalization since 1 November 2022 and prospectively followed until 9 January 2023. A Poisson regression model was used to estimate the VE. 16(1.15%) COVID-19-related hospitalizations were reported in 1391 unvaccinated participants; 7(0.25%) in 2765 participants with two doses, resulting in a VE of 70.89%(95% confidence interval[CI] 26.25 to 87.73); 32(0.27%) in 11,846 participants with three doses, with a VE of 65.25%(95% CI 32.24 to 81.83). The VE of three doses remained above 64% at 1 year or more since the last dose. Elderly people aged ≥ 60 years had the highest hospitalization incidence(0.66%), VE for two doses was 74.11%(95%CI: − 18.42 to 94.34) and VE for three doses was 80.98%(95%CI:52.83 to 92.33). We estimated that vaccination had averted 65,007(95%CI: 12,817 to 97,757) COVID-19-related hospitalizations among people aged ≥ 60 years during the BF.7-predominant period in Beijing. Inactivated COVID-19 vaccines were effective against COVID-19-related hospitalization, especially for the elderly population who have increased risk of severe disease owing to SARS-CoV-2 infection.