Vaccination Is Associated With Shorter Time to Target Cycle Threshold Value in Patients With SARS-CoV-2 Omicron Variant

Abstract

BackgroundLimited data are available on the responses to vaccination for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant in the Chinese population. This study aimed to investigate whether vaccination could alter the disease course of SARS-CoV-2 Omicron variant.MethodsA retrospective cohort included 142 patients who had no or mild symptoms and were admitted to our department for centralized isolation after being locally infected with SARS-CoV-2 Omicron variant from March 4 to 30, 2022, in Shanghai, China.ResultsOf the 142 subjects with the mean age of 43.1 years, 53.5% were male and 90.8% had been vaccinated before the infection. Comparing the vaccinated with the unvaccinated patients, there was no difference in patient characteristics, but patients with vaccination had shorter time to target cycle threshold value (TtCT) (vaccinated vs. unvaccinated, 12.6 ± 3.4 vs. 14.8 ± 4.7 days, P = 0.039). There was no difference in TtCT between heterogeneous and homologous vaccination. Of subjects with homologous vaccination, 43.1% were vaccinated with CoronaVac (Sinovac Life Science), 47.2% with Sinopharm BBIBP-CorV, 4.9% with Sinopharm WIBP, 3.3% with CanSinoBio, and 1.6% with Zhifei Longcom. No difference in TtCT was observed among different vaccines. Comparing two-dose primary vaccination with three-dose booster vaccination, we found no difference in TtCT either.ConclusionVaccination is associated with shorter TtCT in patients with SARS-CoV-2 Omicron variant.

Association of clinical characteristics and vaccines with risk of persistently viral clearance in patients infected with SARS-CoV-2 Omicron variant in Shanghai, China

“…This protection waned significantly after 6 months. However, Wu et al [ 10 ] found that a three-dose booster vaccination did not attenuate the target Ct value compared with a two-dose primary vaccination. Munro et al [ 34 ] conducted a multicenter, blinded, phase 2, randomized controlled trial to investigate the effectiveness of four-dose boosters against COVID-19.…”

“…There have been some reports on risk factors that influence the persistence of SARS-CoV-2 RNA shedding [ [7] , [8] , [9] ]. In a recent study of 142 patients with SARS-CoV-2 Omicron variant infection from March 4 to 30, 2022 in China, vaccination was found to be a protective factor against shorter viral shedding time in these patients [ 10 ]. Herein, the effect of SARS-CoV-2 vaccines on viral clearance time was investigated.…”

So Sánh Đặc Điểm Cycle Threshold-Polymerase Chain Reaction Và Kết Quả Điều Trị Giữa Người Bệnh Covid-19 Thể Nhẹ Có Và Không Triệu Chứng

“…Nghiên cứu của chúng tôi cũng thấy rằng giá trị CT giữa 2 nhóm tiêm và không tiêm vắc-xin cũng không có sự khác biệt. Khác với chúng tôi, nghiên cứu của tác giả Wu và cộng sự trên 142 người bệnh COVID-19 cho thấy nhóm tiêm vắc-xin chỉ mất trung bình 12.6 ngày để đạt mức CT≥35, so với 14.8 ngày ở nhóm không tiêm vắc-xin [10]. Sự khác biệt này liên quan đến sự khác nhau về thời điểm khảo sát, do nguồn lực y tế giới hạn nên chúng tôi chỉ có thể đánh giá CT-PCR vào 1 thời điểm ngày 7 sau theo dõi, điều trị.…”

Epidemiological characteristics of patients from fever clinics during the COVID-19 epidemic in 2022 in Shanghai, China

“…Earlier clinical studies on wild strains of SARS-CoV-2 showed that laboratory indicators of infection, such as lymphocyte count, T lymphocyte count, liver enzyme index, myocardial enzyme index, and D-dimer, are useful for predicting whether patients develop severe disease [ 9 , 10 ]. The Omicron variant strain has been reported to have a shorter incubation period, higher infectivity, and pathogenicity and to produce a higher viral load than the original strain [ 11 ]. The local outbreak in Shanghai occurred after widespread vaccination of the population against COVID-19.…”