Characteristics of humoral and cellular responses to coronavirus disease 2019 (COVID-19) inactivated vaccine in central China: A prospective, multicenter, longitudinal study

Abstract

IntroductionIn China, the long-term immunogenicity and adverse effects of inactivated vaccines produced by different or the same manufacturer remain unclear. Therefore, the objective of this study was to evaluate the cellular immune responses and neutralizing antibody kinetics of homologous and heterologous administrations of an inactivated coronavirus disease 2019 (COVID-19) vaccine 240 days after the second vaccination.MethodsThis prospective, multicenter, observational, longitudinal study involved 595 participants with a negative SARS-CoV-2 polymerase chain reaction result who were serologically tested and followed for 8 months after vaccination. Neutralizing antibodies, interferon-gamma (IFN-γ), interleukin (IL)-6, CD4+ T-lymphocyte, and B-lymphocyte counts were evaluated in serum samples after stimulation with 2 μg/mL SARS-CoV-2 spike protein for 16 h at follow-up intervals of 2 months.ResultsMost participants [582/595; 146 male participants, 449 female participants; mean age 35 (26–50 years)] rapidly developed neutralizing antibodies after two doses of the vaccine administered 3-weeks apart. The positive rate of neutralizing antibodies peaked at 97.7% at 60–90 days, decreased, and stabilized at 82.9% at 181–240 days post-vaccination. Lower antibody concentrations were correlated with older age, longer duration after vaccination, non-health care workers, mixed-manufacturer vaccinations, and intervals of less than 40 days between two doses of vaccination, whereas lower IFN-γ levels and B-lymphocyte counts were associated with older age, blood type A, and non-health care workers. A higher IL-6 level was associated with older age, mixed-manufacturer vaccinations, intervals of less than 40 days between two doses of vaccination, and medical staff. Adverse reactions were mild or moderate and self-limited, with no serious events reported.DiscussionTwo doses of the Chinese inactivated vaccine induced robust and rapid antibody expression and cellular immune responses. Boosting vaccination is considered important, as antibodies and cellular immune responses were reduced in susceptible populations.

Prolonged SARS-CoV-2 T Cell Responses in a Vaccinated COVID-19-Naive Population

“…Similarly, mRNA vaccines conferred high cellular responses almost eight months post-vaccination, whereas antibody levels had drastically waned [ 26 ]. On the other hand, in a multicenter, longitudinal study, robust cellular responses with detectable humoral immunity were documented up to eight months after complete vaccination [ 27 ].…”

SARS-CoV-2 Vaccine Uptake among Patients with Chronic Liver Disease: A Cross-Sectional Analysis in Hebei Province, China

“…The variation was due to the differences in the population size, vaccine brand, survey time, etc. (http://health.people.com.cn/n1/2021/0528/c14739-32116490.html, accessed on 27 July 2023) [20][21][22][23][24][25][26][27]. Moreover, considering the differences in physical function, the impact of the vaccines on liver function needed to be further analyzed in CLD patients to reflect vaccine safety.…”

Retrospective analysis of COVID-19 among 391 hospitalized patients in the Henan province of China

“…Vaccination status against influenza or COVID-19 vaccines can affect the immune status of COVID-19 patients and uninfected individuals, which is the primary factor affecting the severity of the disease. [26,27] Patient vaccinations were not included in this analysis since this information was missing from the electronic medical records.…”

“…The 2 groups were similar in sex composition (P > .005). There were more patients with severe COVID-19 among those aged > 50 years (27,15.2%) than in the 0 to 50 years group (1, 0.5%; P < .001). The > 50 years age group was characterized by a higher proportion of comorbidities (64% vs 36%; P < .001).…”