Background: Coronavirus disease 2019, otherwise known as COVID-19 is caused by the novel coronavirus. The WHO stated that as of April 24, 2020, no study has evaluated if the antibodies against COVID-19 confer immunity. The aim therefore of this research is to determine the presence of neutralizing antibodies among fully vaccinated Health Care workers and staff of Notre Dame de Chartres Hospital. Methods: This study is a single-center, cross-sectional study conducted at Notre Dame de Chartres Hospital in Baguio City. This study was designed to determine the presence of neutralizing antibodies 6 months after the 2nd dose of COVID-19 vaccine, either with Sinovac (CoronaVac®), an inactivated virus, or Oxford AstraZeneca, a non-replicating viral vector. The study was approved by the Ethics Review Board of the Baguio General Hospital Medical Center. A total of 206 participants enrolled voluntarily in the study. Descriptive statistics such as frequency and percentage were used to determine the baseline characteristics of the research participants. The mean amounts of antibodies after vaccination against COVID-19 were determined. Independent-sample t-test was utilized to determine if there was a significant difference in antibody production when comparing the two brands of vaccine, according to sex, employee status, presence of at least one comorbidity, and history of COVID-19 vaccination. One-way analysis of variance (ANOVA) was used for the variable age. All statistical tests were conducted at p<0.05 level of significance. Computations were done using SPSS version 22.0. Results: A total of 236 healthcare workers and staff of Notre Dame de Chartres Hospital were included in the study. Among the study participants given either Sinovac or AstraZeneca, 52.97% belong to the 20-30 years old age group. Most of them were females (69.92%). For employment status, healthcare workers comprised the majority of the study population at 71.61% while the rest (28.36%) were hospital staff. Most did not have any comorbidities, while 26.27% reported having comorbidities, with hypertension and asthma identified as the predominant diseases at 9.75% and 9.32%, respectively; followed by allergic rhinitis (5.32%) and diabetes mellitus (2.97%). Among the participants, 74.6% were never diagnosed with COVID-19, while 25.4% reported to have been infected, with 16.5% having only mild symptoms. Most of the study participants (67.4%) were inoculated with Sinovac® while the rest (32.6%) received AstraZeneca. Conclusion There was no significant difference in the mean amount of antibodies when grouped according to each of the following variables: age, sex, employee status, and comorbidities. These results apply to both SINOVAC and AstraZeneca groups. There was a significantly higher mean amount of antibodies in those who had previously contracted COVID-19 than in those who never had a previous infection. On the other hand, comparing the mean amount of antibodies between the two brands of vaccines, SinovacTM and AstraZenecaTM, those who were vaccinated with AstraZenecaTM developed higher amounts of antibodies than those who were vaccinated with SinovacTM.
Neutralizing antibodies ; COVID-19 vaccine ; healthcare workers

Background: Baguio General Hospital and Medical Center (BGHMC) and Benguet General Hospital (BeGH) started COVID-19 vaccination among its employees in March 2021. Although there was an observed substantial increase in vaccine acceptance, a better understanding on the factors associated with hesitancy toward COVID-19 vaccine is necessary to further strengthen efforts and focus on the caveats regarding vaccine acceptance. Objective: The study aimed to determine the factors influencing COVID-19 vaccine hesitancy among healthcare workers (HCW) in two general hospitals in Benguet. Methods: A cross-sectional study was conducted among HCW in BGHMC and BeGH for 1 month. Total enumeration sampling was used which included 222 participants but only 85 responded. A modified questionnaire was used to describe the factors influencing COVID-19 vaccine hesitancy. Categorical variables were presented as frequencies and percentages. Pearson’s Chisquare test was used to observe the association between clinicodemographic factors and COVID-19 vaccine hesitancy among the HCW in BGHMC and BeGH. Results: The results showed that young, female, non-clinical workers with direct contact with COVID-19 patients, previous COVID-19 infection, and without comorbidities were more likely to be hesitant. The study identified various internal, external, and vaccination-specific factors that influenced vaccine hesitancy, such as concerns about adverse effects, their impending risk in contracting COVID-19 at workplace, and thoughts about yearly booster dose. These findings suggest that vaccine hesitancy among healthcare workers in the Philippines is complex and influenced by a range of factors. Conclusion The study can be used to develop targeted interventions to address concerns about vaccine hesitancy and improve vaccine uptake among healthcare workers. The development of an equitable approach such as an effective and inclusive vaccine policy that does not feel mandatory for this population will foster trust in the healthcare system.
COVID-19 vaccine ; Vaccine hesitancy ; Healthcare workers ; General Hospital

Humans ; BNT162 Vaccine ; Anaphylaxis/etiology* ; COVID-19/prevention & control*

BACKGROUND: Asymptomatic or symptomatic infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can be followed by reinfection. The protection conferred by prior infection among coronavirus disease 2019 (COVID-19) patients is unclear. We assessed the incidence of SARS-CoV-2 reinfection and the protection effect of previous infection against reinfection. METHODS: We searched PubMed, EMBASE, Cochrane, Scopus, Web of Science, and ClinicalTrials.gov for publications up until the end date of May 1, 2021. The reinfection rate of recovered patients and the protection against reinfection were analyzed using meta-analysis. RESULTS: Overall, 19 studies of 1096 reinfection patients were included. The pooled reinfection rate was 0.65% (95% confidence interval [CI] 0.39-0.98%). The symptomatic reinfection rate was a bit lower (0.37% [95% CI 0.11-0.78%], I2 = 99%). The reinfection rate was much higher in high-risk populations (1.59% [95% CI 0.30-3.88%], I2 = 90%). The protection against reinfection and symptomatic reinfection was similar (87.02% [95% CI 83.22-89.96%] and 87.17% [95% CI 83.09-90.26%], respectively). CONCLUSIONS The rate of reinfection with SARS-CoV-2 is relatively low. The protection against SARS-CoV-2 after natural infection is comparable to that estimated for vaccine efficacy. These data may help guide public health measures and vaccination strategies in response to the COVID-19 pandemic. High-quality clinical studies are needed to establish the relevant risk factors in recovered patients.
COVID-19 ; Humans ; Pandemics ; Reinfection ; SARS-CoV-2 ; Vaccine Efficacy

Confronted with the Coronavirus disease 2019 (COVID-19) pandemic, China has become an asset in tackling the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission and mutation, with several innovative platforms, which provides various technical means in this persisting combat. Derived from collaborated researches, vaccines based on the spike protein of SARS-CoV-2 or inactivated whole virus are a cornerstone of the public health response to COVID-19. Herein, we outline representative vaccines in multiple routes, while the merits and plights of the existing vaccine strategies are also summarized. Likewise, new technologies may provide more potent or broader immunity and will contribute to fight against hypermutated SARS-CoV-2 variants. All in all, with the ultimate aim of delivering robust and durable protection that is resilient to emerging infectious disease, alongside the traditional routes, the discovery of innovative approach to developing effective vaccines based on virus properties remains our top priority.
Humans ; COVID-19 Vaccines ; COVID-19/prevention & control* ; SARS-CoV-2 ; China/epidemiology* ; Vaccine Development

The Delta variant of the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has caused a new global wave of the Coronavirus Disease 2019 (COVID-19) pandemic. COVID-19 vaccines currently available in China show high effectiveness against severe illness and death. However, transmission of the virus is not fully stopped by vaccination alone, therefore, integrated vaccination and non-pharmacological interventions is necessary to prevent and control the epidemic in the near future. Further expanded vaccine coverage of primary doses as well as booster shots in China's domestic population are needed to reduce severe illness and death. In order to provide evidence necessary for adjusting and optimizing immunization strategies and pandemic control measures, it is essential to conduct research on vaccine effectiveness against emerging variants, persistence of vaccine-induced protection, surveillance of adverse event following immunization with large-scale vaccine use, and modelling studies on strategic combinations of vaccination and non-pharmacological interventions.
COVID-19 ; COVID-19 Vaccines ; China ; Humans ; Immunization, Secondary ; SARS-CoV-2 ; Vaccination ; Vaccine Efficacy

Messenger RNA (mRNA) vaccines emerge as promising vaccines to prevent infectious diseases. Compared with traditional vaccines, mRNA vaccines present numerous advantages, such as high potency, safe administration, rapid production potentials, and cost-effective manufacturing. In 2020, two COVID-19 vaccines (BNT162b2 and mRNA-1273) were approved by the Food and Drug Administration (FDA). The two vaccines showed high efficiency in combating COVID-19, which indicates the great advantages of mRNA technology in developing vaccines against emergent infectious diseases. Here, we summarize the type, immune mechanisms, modification methods of mRNA vaccines, and their applications in preventing infectious diseases. Current challenges and future perspectives in developing mRNA vaccines are also discussed.
United States ; Humans ; mRNA Vaccines ; BNT162 Vaccine ; COVID-19 Vaccines/genetics* ; Communicable Diseases ; RNA, Messenger/genetics*

Since the Global Polio Eradication Initiative was launched by the World Health Assembly in 1988, significant progress has been made in global polio prevention and control. But the occurrence of vaccine-associated paralytic poliomyelitis cases and vaccine-derived poliovirus related cases have become a major challenge during the post-polio era. While coronavirus disease 2019(COVID-19) has brought serious disease burden and economic burden to all countries in the world, prevention and control of vaccine-preventable infectious diseases such as polio should not be neglected under the background of the global common fight against COVID-19. Taking the type Ⅲ VDPV cycle event in Shanghai as an example, the paper discussed how to do a good job of routine inoculation under the prevention and control of COVID-19 to strictly prevent the outbreak of vaccine-preventable infectious diseases.
COVID-19 ; China ; Humans ; Poliovirus ; Poliovirus Vaccine, Oral ; SARS-CoV-2 ; Vaccination

Inducing durable and effective immunity against severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2) via vaccination is essential to combat the current pandemic of coronavirus disease 2019 (COVID-19). It has been noticed that the strength of anti-COVID-19 vaccination-induced immunity fades over time, which calls for an additional vaccination regime, as known as booster immunization, to restore immunity among previously vaccinated populations. Here we report a pilot open-label trial of a third dose of BBIBP-CorV, an inactivated SARS-CoV-2 vaccine (Vero cell), on 136 participants aged between 18 to 63 years. Safety and immunogenicity in terms of neutralizing antibody titers and cytokine/chemokine responses were analyzed as the main endpoint until day 28. While systemic reactogenicity was either absent or mild, SARS-CoV-2-specific neutralizing antibody titers rapidly arose in all participants within 4 weeks, surpassing the peak antibody titers elicited by the initial two-dose immunization regime. Broad increases of cellular immunity-associated cytokines and chemokines were also detected in the majority of participants after the third vaccination. Furthermore, in an exploratory study, a newly developed recombinant protein vaccine, NVSI-06-08 (CHO Cells), was found to be safe and even more effective than BBIBP-CorV in eliciting humoral immune responses in BBIBP-CorV-primed individuals. Together, these results indicate that a third immunization schedule with either homologous or heterologous vaccine showed favorable safety profiles and restored potent SARS-CoV-2-specific immunity, providing support for further trials of booster vaccination in larger populations.
Adolescent ; Adult ; Antibodies, Neutralizing ; Antibodies, Viral ; COVID-19/prevention & control* ; COVID-19 Vaccines/adverse effects* ; China ; Humans ; Immunogenicity, Vaccine ; Middle Aged ; SARS-CoV-2 ; Vaccination ; Young Adult

BACKGROUND: Data on the immunogenicity and safety of heterologous immunization schedules are inconsistent. This study aimed to evaluate the immunogenicity and safety of homologous and heterologous immunization schedules. METHODS: Multiple databases with relevant studies were searched with an end date of October 31, 2021, and a website including a series of Coronavirus disease 2019 studies was examined for studies before March 31, 2022. Randomized controlled trials (RCTs) that compared different heterologous and homologous regimens among adults that reported immunogenicity and safety outcomes were reviewed. Primary outcomes included neutralizing antibodies against the original strain and serious adverse events (SAEs). A network meta-analysis (NMA) was conducted using a random-effects model. RESULTS: In all, 11 RCTs were included in the systematic review, and nine were ultimately included in the NMA. Among participants who received two doses of CoronaVac, another dose of mRNA or a non-replicating viral vector vaccine resulted in a significantly higher level of neutralizing antibody than a third CoronaVac 600 sino unit (SU); a dose of BNT162b2 induced the highest geometric mean ratio (GMR) of 15.24, 95% confidence interval [CI]: 9.53-24.39. Following one dose of BNT162b2 vaccination, a dose of mRNA-1273 generated a significantly higher level of neutralizing antibody than BNT162b2 alone (GMR = 1.32; 95% CI: 1.06-1.64), NVX-CoV2373 (GMR = 1.60; 95% CI: 1.16-2.21), or ChAdOx1 (GMR = 1.80; 95% CI: 1.25-2.59). Following one dose of ChAdOx1, a dose of mRNA-1273 was also more effective for improving antibody levels than ChAdOx1 (GMR = 11.09; 95% CI: 8.36-14.71) or NVX-CoV2373 (GMR = 2.87; 95% CI: 1.08-3.91). No significant difference in the risk for SAEs was found in any comparisons. CONCLUSIONS: Relative to vaccination with two doses of CoronaVac, a dose of BNT162b2 as a booster substantially enhances immunogenicity reactions and has a relatively acceptable risk for SAEs relative to other vaccines. For primary vaccination, schedules including mRNA vaccines induce a greater immune response. However, the comparatively higher risk for local and systemic adverse events introduced by mRNA vaccines should be noted. REGISTRATION PROSPERO; https://www.crd.york.ac.uk/PROSPERO/ ; No. CRD42021278149.
Adult ; Humans ; BNT162 Vaccine ; 2019-nCoV Vaccine mRNA-1273 ; Network Meta-Analysis ; Immunization Schedule ; COVID-19/prevention & control* ; COVID-19 Vaccines/adverse effects* ; Viral Vaccines ; mRNA Vaccines ; Antibodies, Neutralizing ; Antibodies, Viral