Effect of homologous or heterologous vaccine booster over two initial doses of inactivated COVID-19 vaccine

INTRODUCTION

Inactivated vaccines were delivered to low- and middle-income countries during the early pandemics of COVID-19. Currently, more than 10 inactivated COVID-19 vaccines have been developed. Most inactivated vaccines contain an inactivated whole-cell index SARS-CoV-2 strain that is adjuvant. Whole virions inactivated with aluminum hydroxide vaccines were among the most commonly used. However, with the emerging of COVID-19 variants and waning of the immunity of two doses of after 3 months, WHO and many local governments have recommended the booster-dose program especially with heterologous platform vaccine.

AREA COVERED

This review was conducted through a literature search of the MEDLINE database to identify articles published from 2020 to 2023 covered the inactivated COVID-19 vaccines primary series with homologous and heterologous booster focusing on safety, immunogenicity, efficacy, and effectiveness.

EXPERT OPINION

The inactivated vaccines, especially whole virion inactivated in aluminum hydroxide appeared to be safe and had good priming effects. Immune responses generated after one dose of heterologous boost were high and able to preventing severity of disease and symptomatic infection. A new approach to inactivated vaccine has been developed using inactivating recombinant vector virus-NDV-HXP-S vaccine.

Pre-existing immunity to SARS-CoV-2 associates with strong T cell responses induced by inactivated COVID-19 vaccines

Individuals with a recent common cold coronavirus infection, which leads to pre-existing immunity against SARS-CoV-2, displayed a less severe course of COVID-19. However, the relationship between pre-existing immunity against SARS-CoV-2 and the inactivated-vaccine-induced immune response is still unknown. Here, thirty-one healthcare workers who received standard two doses of inactivated COVID-19 vaccines (week 0 and 4, respectively) were enrolled, vaccine-induced neutralization and T cell responses were detected, and the correlation between the pre-existing SARS-CoV-2-specific immunity was analyzed. We found the SARS-CoV-2-specific antibodies, pVNT titers, and spike-specific IFN-γ production in CD4⁺ and CD8⁺ T cells were significantly elevated after two doses of inactivated vaccines. Interestingly, the pVNT titers after the second dose of vaccination displayed no significant correlation with the pre-existing SARS-CoV-2-specific antibodies or B cells, nor the pre-existing spike-specific CD4⁺ T cells. Notably, the spike-specific T cell response after the second dose of vaccination was positively correlated with the pre-existing RBD-specific B cells and CD4⁺ T cells, which were documented by the frequencies of RBD-binding B cells, the breadth of RBD-specific B cell epitopes, and the frequency of IFN-γ-expressing RBD-specific CD4⁺ T cells. Overall, the inactivated-vaccine-induced T cell responses, not the inactivated-vaccine-induced neutralization, closely correlated with pre-existing immunity to SARS-CoV-2. Our results provide a better understanding of inactivated-vaccine-induced immunity and help predict the immunogenicity induced by inactivated vaccines in individuals. This article is protected by copyright. All rights reserved.

Humoral and cellular immunity of two-dose inactivated COVID-19 vaccination in Chinese children: A prospective cohort study

Children are the high-risk group for COVID-19, and in need of vaccination. However, humoral and cellular immune responses of COVID-19 vaccine remain unclear in vaccinated children. To establish the rational immunization strategy of inactivated COVID-19 vaccine for children, the immunogenicity of either one dose or two doses of the vaccine in children was evaluated. A prospective cohort study of 322 children receiving inactivated COVID-19 vaccine was established in China. The baseline was conducted after 28 days of the first dose, and the follow-up was conducted after 28 days of the second dose. The median titers of receptor binding domain (RBD)-IgG, and neutralizing antibody (NAb) against prototype strain and Omicron variant after the second dose increased significantly compared to those after the first dose (first dose: 70.0, [interquartile range, 30.0-151.0] vs. second dose: 1261.0 [636.0-2060.0] for RBD-IgG; 2.5 [2.5-18.6] vs. 252.0 [138.6-462.1] for NAb against prototype strain; 2.5 [2.5-2.5] vs. 15.0 [7.8-26.5] for NAb against Omicron variant, all p < 0.05). The flow cytometry results showed that the first dose elicited SARS-CoV-2 specific cellular immunity, while the second dose strengthened SARS-CoV-2 specific IL-2⁺ or TNF-α⁺  monofunctional, IFN-γ⁺ TNF-α⁺  bifunctional, and IFN-γ^- IL-2⁺ TNF-α⁺ multifunctional CD4⁺ T cell responses (p < 0.05). Moreover, SARS-CoV-2 specific memory T cells were generated after the first vaccination, including the central memory T cells and effector memory T cells. The present findings provide scientific evidence for the vaccination strategy of the inactive vaccines among children against COVID-19 pandemic.

Web-Based Reporting of Post-Vaccination Symptoms for Inactivated COVID-19 Vaccines in Jordan: A Cross-Sectional Study

BACKGROUND

The perception of COVID-19 vaccines as being unsafe is a major barrier to receiving the vaccine. Providing the public with accurate data regarding the vaccines would reduce vaccine hesitancy.

METHODS

A cross-sectional study was conducted to collect data on the side effects experienced by the vaccinated population to assess the safety of the inactivated COVID-19 vaccine.

RESULTS

The majority of the study participants (n = 386) were female (71.9%), and 38.6% of them were under 30 years old. Around half of the participants (52.8%) reported side effects after receiving the inactivated COVID-19 vaccine. Fatigue (85.1%), a sore arm at the site of the injection (82.1%), and discomfort (67.2%) were the most commonly reported side effects after the first dose. Reporting side effects was significantly associated with the female sex (p-value = 0.027). Significant associations between being female and experiencing chills, muscle or joint pain, anorexia, drowsiness, and hair loss were also found, as well as being above the age of 30 and experiencing a cough. Being a smoker was significantly associated with experiencing a cough, and a headache. Furthermore, chills, and a sore throat were significantly associated with individuals who had not been infected before.

CONCLUSION

Mild side effects were reported after receiving the inactivated COVID-19 vaccine. Fatigue was the most commonly reported side effect. Females, older adults, smokers, and those who had never been infected with COVID-19 had a greater susceptibility to certain side effects.

Safety and immunogenicity of inactivated COVID-19 vaccine in patients with metabolic syndrome: A cross-sectional observational study

Background and aims

The prevalence of metabolic syndrome (MS), wich mainly including hypertension, hyperglycemia, hyperlipidemia, remains high, and the safety and antibody response of inactivated coronavirus disease 2019 (COVID-19) vaccination in patients with metabolic syndrome (MS) is still inconsistency, therefore it is necessary to explore the safety and antibody responses of inactivated COVID-19 vaccination in MS patients in clinical practice.

Methods

157 adults patients who were suffering from MS and 117 health controls (HC) at an interval of at least 21 days after full-course (2nd dose) vaccination were enrolled. The safety of inactivated COVID-19 vaccination was evaluated through collected adverse events (AEs) by questionnaire. The immunogenicity of included participant to inactivated COVID-19 vaccination was represented by serum seropositivity rate of anti-receptor binding domain (RBD) IgG, SARS-CoV-2 neutralizing antibodies (CoV-2 Nab) and titers of anti-RBD IgG, CoV-2 Nab. The B cells, mainly including RBD-specific B cells, RBD-specific memory B cell (MBC), RBD⁺ resting MBC cells, RBD⁺ activated MBC cells, RBD⁺ atypical MBC cells (atyMBCs), and RBD⁺ intermediate MBC cells, were also analyzed.

Results

In terms of safety, all AEs in MS patients were mild and self-limiting, and the incidence was comparable to that of HC participants, with overall AEs within seven days reported in 9.6% (15/157) of 3H and 11.1% (13/117) of HC. Both groups experienced no serious adverse events. As for immunogenicity of MS patients to inactivated COVID-19 vaccination, compared with health controls, the seroprevalence of anti-RBD IgG and CoV-2 Nab was significantly decreased in MS patients (p = 0.000, p = 0.003, respectively), while the titers of anti-RBD IgG (AU/ml) and CoV-2 Nab (μg/ml) were also significant lower in MS patients (p = 0.014, p = 0.002, respectively). As for frequencies of B cells, MS patients had lower frequencies of RBD-specific B cells, RBD⁺ resting MBCs, and RBD⁺ intermediate MBCs (p = 0.003, p = 0.000, p = 0.000, respectively), but had a higher frequencies of RBD⁺ atypical MBCs (p = 0.000) than HC. In comorbidity number subgroups analysis of MS, except frequencies of RBD⁺ resting MBC cells, RBD⁺ activated MBC cells and RBD⁺ intermediate MBC cells had significant difference among three groups (p = 0.035, p = 0.042, p = 0.046, respectively), antibody response had no significant difference among 1H, 2H, and 3H groups (p > 0.05). And took 70 years old as a boundary, also no statistically significant differences (p > 0.05) were found in age subgroups. Lastly, comprehensive analysis in MS patients indicated that interval time after 2nd dose vaccine was the statistical significant factor which impacting antibody response in MS individuals.

Conclusions

Inactivated COVID-19 vaccines were well-tolerated, but induced a poorer antibody response against SARS-CoV-2 in MS patients comparing to HC participants. Patients with MS should therefore be more proactive in receiving inactivated COVID-19 vaccine, and a booster vaccination may be considered necessary.

Clinical trial registration

https://clinicaltrials.gov/, identifier: NCT05043246.

Failure to seroconvert after three doses of inactivated COVID-19 vaccines in a patient co-infected with HBV and HIV: A case report

In the global context of the COVID-19 pandemic, the overall benefits of getting any COVID-19 vaccine approved by the World Health Organization for emergency use outweigh the potential risks, even in people with weakened immune systems, including people living with HIV (PLWH). At present, there are no reports of HIV/hepatitis B virus (HBV) co-infected patients receiving a booster dose of the inactivated COVID-19 vaccine. Here, we describe a patient with HIV/HBV co-infection who did not seroconvert to three doses of the inactivated COVID-19 vaccine.

Vaccine Adverse Events Following COVID-19 Vaccination with Inactivated Vaccines in Zimbabwe

Vaccination is one of the most effective methods for preventing morbidity and mortality from COVID-19. Vaccine hesitancy has led to a decrease in vaccine uptake; driven by misinformation, fear, and misperceptions of vaccine safety. Whole inactivated vaccines have been used in one-fifth of the vaccine recipients in Africa, however there are limited real-world data on their safety. We evaluated the reported adverse events and factors associated with reported adverse events following vaccination with whole inactivated COVID-19 vaccines-BBiBP-CorV (Sinopharm) and CoronaVac (Sinovac). A quantitative survey evaluating attitudes and adverse events from vaccination was administered to 1016 adults presenting at vaccination centers. Two follow-up telephone interviews were conducted to determine adverse events after the first and second vaccination dose. Overall, the vaccine was well tolerated; 26.0% and 14.4% reported adverse events after the first and second dose, respectively. The most frequent local and systemic adverse events were pain at the injection site and headaches, respectively. Most symptoms were mild, and no participants required hospitalization. Participants who perceived COVID-19 vaccines as safe or had a personal COVID-19 experience were significantly less likely to report adverse events. Our findings provide data on the safety and tolerability of whole inactivated COVID-19 vaccines in an African population, providing the necessary data to create effective strategies to increase vaccination and support vaccination campaigns.

Humoral responses after inactivated COVID-19 vaccination in individuals with and without prior SARS-CoV-2 infection: A prospective cohort study

We evaluated and compared humoral immune responses after inactivated coronavirus disease 2019 (COVID-19) vaccination among naïve individuals, asymptomatically infected individuals, and recovered patients with varying severity. In this multicenter, prospective cohort study, blood samples from 666 participants were collected before and after 2 doses of inactivated COVID-19 vaccination. Among 392 severe acute respiratory syndrome coronavirus 2-naïve individuals, the seroconversion rate increased significantly from 51.8% (median antispike protein pan-immunoglobulins [S-Igs] titer: 0.8 U/ml) after the first dose to 96% (median S-Igs titer: 79.5 U/ml) after the second dose. Thirty-two percent of naïve individuals had detectable neutralizing antibodies (NAbs) against the original strain but all of them lost neutralizing activity against the Omicron variant. In 274 individuals with natural infection, humoral immunity was significantly improved after a single vaccine dose, with median S-Igs titers of 596.7, 1176, 1086.5, and 1828 U/ml for asymptomatic infections, mild cases, moderate cases, and severe/critical cases, respectively. NAb titers also improved significantly. However, the second dose did not substantially increase antibody levels. Although a booster dose is needed for those without infection, our findings indicate that recovered patients should receive only a single dose of the vaccine, regardless of the clinical severity, until there is sufficient evidence to confirm the benefits of a second dose.

Case Report: Anti-NF186+ CIDP After Receiving the Inactivated Vaccine for Coronavirus Disease (COVID-19)

Corona Virus Disease 2019 (COVID-19), the novel coronavirus disease, is now a global pandemic. Vaccination can significantly reduce the mortality rate caused by the severe acute respiratory syndrome of coronavirus 2 (SARS-CoV-2). There are currently several effective vaccines that have been introduced. Inactivated COVID-19 vaccine is one of these options and is generally considered safe. Neurofascin (NF) plays an important role in keeping the functionality of the node of Ranvier. We report here a rare case of anti-NF186+ chronic inflammatory demyelinating polyneuropathy (CIDP) in a 23-year-old male patient who was vaccinated with inactivated COVID-19 vaccine prior to the onset. This report adds a new possible rare side effect of a COVID-19 vaccine and provides a case for the clinical effectiveness of rituximab (RTX) in patients with anti-NF186+ CIDP.

Evaluation of Immunogenicity by Pseudovirus Neutralization Assays for Coronavirus Disease 2019 (COVID-19) Variants after Primary and Booster Immunization

OBJECTIVES

To determine the status of immune responses after primary and booster immunization for coronavirus disease 2019 (COVID-19) variants and evaluate the differences in disease-resistance based upon titers of neutralizing antibodies (NAbs) against the variants.

METHODS

Participants aged 18 - 59 y received two doses of inactivated COVID-19 vaccine, 14 days apart, and a booster dose after 12 m. Blood samples were collected before vaccination (baseline), 1 and 6 m after primary immunization, and at multiple instances within 21 d of booster dose. NAbs against the spike protein of Wuhan-Hu-1 and three variants were measured using pseudovirus neutralization assays.

RESULTS

Out of 400 enrolled participants, 387 completed visits scheduled within 6 m of the second dose, and 346 participated received the booster dose in the follow-up research. After 1 m of primary immunization, geometric mean titers (GMTs) of NAbs peaked for Wuhan-Hu-1, while GMTs of other variants were < 30. After 6 m of primary immunization, GMTs of NAbs against all strains were < 30. After 3 d of booster immunization, GMTs were unaltered, seroconversion rates reached approximately 50% after 7 d, and GMTs of NAbs against all strains peaked at 14 d.

CONCLUSION

Two-dose of inactivated COVID-19 vaccine induced the formation of NAbs and memory-associated immune responses, and high titers of NAbs against the variants obtained after booster immunization may further improve the effectiveness of the vaccine.