Assessment of safety and intranasal neutralizing antibodies of HPMC-based human anti-SARS-CoV-2 IgG1 nasal spray in healthy volunteers.

An HPMC-based nasal spray solution containing human IgG1 antibodies against SARS-CoV-2 (nasal antibody spray or NAS) was developed to strengthen COVID-19 management. NAS exhibited potent broadly neutralizing activities against SARS-CoV-2 with PVNT values ranging from 0.0035 to 3.

The immunogenicity and reactogenicity of four COVID-19 booster vaccinations against SARS-CoV-2 variants following CoronaVac or ChAdOx1 nCoV-19 primary series.

Background: The appropriate COVID-19 booster vaccine following inactivated or adenoviral vector COVID-19 vaccination is unclear.

Objective: To investigate the immunogenicity of four COVID-19 booster vaccines.

Methods: We prospectively enrolled healthy adults who received a two-dose CoronaVac or ChAdOx1 8-12 weeks earlier and allocated them to receive one of the following booster vaccine: inactivated (BBIBP-CorV), ChAdOx1 or mRNA (BNT162b2 at full [30 μg] and half [15 μg] dose) vaccines.

CHO-produced RBD-Fc subunit vaccines with alternative adjuvants generate immune responses against SARS-CoV-2.

Subunit vaccines feature critical advantages over other vaccine platforms such as stability, price, and minimal adverse effects. To maximize immunological protection of subunit vaccines, adjuvants are considered as main components that are formulated within the subunit vaccine. They can modulate adverse effects and enhance immune outcomes.

Evaluation of the Safety and Immunogenicity of Fractional Intradermal COVID-19 Vaccines as a Booster: A Pilot Study.

Intradermal vaccination using fractional dosages of the standard vaccine dose is one strategy to improve access to COVID-19 immunization. We conducted a pilot study in healthy adults in Thailand to evaluate the safety and immunogenicity of intradermal administration of fractional doses of ChAdOx1 (1/5th of standard dosage) or BNT162b2 (1/6th of standard dosage) to individuals previously vaccinated (prime) with two-dose intramuscular CoronaVac, ChAdOx1 or BNT162b2. Following an initial immunogenicity exploratory phase for each vaccine combination group ( = 10), a total of 135 participants ( = 45 per group) were recruited to 3 groups (CoronaVac prime-intradermal BNT162b2 boost, CoronaVac prime-intradermal ChAdOx1 boost and ChAdOx1 prime-intradermal BNT162b2 boost) and their immunogenicity data were compared to a previous cohort who received the same vaccine intramuscularly.

Immunogenicity and safety of an intradermal ChAdOx1 nCoV-19 boost in a healthy population.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a global pandemic. Two doses of an inactivated SARS-CoV-2 vaccine (CoronaVac) have been shown to be insufficient to protect against variants of concern (VOCs), while viral vector vaccines remain protective against the infection. Herein, we conducted a preliminary study to evaluate the safety and immunity in an adult population who received the conventional 2 dosage-regimen of inactivated SARS-CoV-2 vaccine; with an additional intradermal ChAdOx1 nCoV-19 reciprocal dosage (1:5).

The Pilot Study of Immunogenicity and Adverse Events of a COVID-19 Vaccine Regimen: Priming with Inactivated Whole SARS-CoV-2 Vaccine (CoronaVac) and Boosting with the Adenoviral Vector (ChAdOx1 nCoV-19) Vaccine.

In response to the SARS-CoV-2 Delta variant, which partially escaped the vaccine-induced immunity provided by two doses of vaccination with CoronaVac (Sinovac), the National Vaccine Committee recommended the heterologous CoronaVac-ChAdOx1 (Oxford−AstraZeneca), a prime−boost vaccine regimen. This pilot study aimed to describe the immunogenicity and adverse events of the heterologous CoronaVac-ChAdOx1 regimen, in comparison with homologous CoronaVac, and homologous ChAdOx1. Between May and August 2021, we recruited a total of 354 participants from four vaccination groups: the CoronaVac-ChAdOx1 vaccinee (n = 155), the homologous CoronaVac vaccinee (n = 32), the homologous ChAdOx1 vaccinee (n = 47), and control group of COVID-19 patients (n = 120).

Comparison of safety and immunogenicity of CoronaVac and ChAdOx1 against the SARS-CoV-2 circulating variants of concern (Alpha, Delta, Beta) in Thai healthcare workers.

Background: Inactivated vaccine (CoronaVac) and chimpanzee adenovirus-vector vaccine (ChAdOx1) have been widely used in resource-limited settings. However, the information on the reactogenicity and immunogenicity of these two vaccines in the same setting are limited.

Methods: Healthy health care workers (HCWs) aged 18 years or older were randomly assigned to receive either two doses of CoronaVac at 4 weeks interval or two doses of ChAdOx1 at 10 weeks interval.

Immunogenicity and Safety of an Intradermal BNT162b2 mRNA Vaccine Booster after Two Doses of Inactivated SARS-CoV-2 Vaccine in Healthy Population.

Effective vaccine coverage is urgently needed to tackle the COVID-19 pandemic. Inactivated vaccines have been introduced in many countries for emergency usage, but have only provided limited protection. Heterologous vaccination is a promising strategy to maximise vaccine immunogenicity.

Intranasal Administration of RBD Nanoparticles Confers Induction of Mucosal and Systemic Immunity against SARS-CoV-2.

Mucosal immunity plays a significant role in host defense against viruses in the respiratory tract. Because the upper respiratory airway is a primary site of SARS-CoV-2 entry, immunization at the mucosa via the intranasal route could potentially lead to induction of local sterilizing immunity that protects against SARS-CoV-2 infection. In this study, we evaluated the immunogenicity of a receptor-binding domain (RBD) of SARS-CoV-2 spike glycoprotein loaded into -trimethyl chitosan nanoparticles (RBD-TMC NPs).

Plant-Produced Receptor-Binding Domain of SARS-CoV-2 Elicits Potent Neutralizing Responses in Mice and Non-human Primates.

The emergence of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has affected global public health and economy. Despite the substantial efforts, only few vaccines are currently approved and some are in the different stages of clinical trials. As the disease rapidly spreads, an affordable and effective vaccine is urgently needed.

DNA vaccine candidate encoding SARS-CoV-2 spike proteins elicited potent humoral and Th1 cell-mediated immune responses in mice.

More than 65 million people have been confirmed infection with SARS-CoV-2 and more than 1 million have died from COVID-19 and this pandemic remains critical worldwide. Effective vaccines are one of the most important strategies to limit the pandemic. Here, we report a construction strategy of DNA vaccine candidates expressing full length wild type SARS-CoV-2 spike (S) protein, S1 or S2 region and their immunogenicity in mice.

Establishment of the national reference standard for tetanus toxoid in Thailand.

The use of reference materials is the basis of standardization and quality control of biologicals such as vaccines produced by different manufacturers and lot-to-lot consistency. The aim of this study was to establish a secondary local and national reference standard of adsorbed tetanus toxoid that can be used for tetanus toxoid vaccine potency testing. Concentrated bulk of tetanus toxoid was adjuvanted and aliquoted before lyophilization.

Review of the current use and evaluation of cell substrates for producing biologicals in selected countries.

In 2010, the WHO guidance document for the evaluation of cell substrates for producing biologicals was replaced with updated recommendations and in May 2013 an implementation workshop on the new recommendations was held in Beijing, China. As part of this workshop, a survey of the use and evaluation of cell substrates for producing biologicals was undertaken and the information obtained was updated in June 2014. The purpose of survey was to capture the status of national requirements related to cell substrates in various countries with particular emphasis on whether or not the updated WHO recommendations had been, or were to be, incorporated into national requirements.

Induction of humoral and cell-mediated immunity to hepatitis B surface antigen by a novel adjuvant activity of Oka varicella vaccine.

Oka varicella vaccine induces humoral and cell-mediated immunity to varicella-zoster virus (VZV), even in immunocompromised hosts. This vaccine showed novel adjuvant activity against co-inoculated hepatitis B surface antigen (HBsAg). Either a mixed inoculation of HBsAg with heat-inactivated Oka varicella vaccine at one site or a separate inoculation of HBsAg and live vaccine at different sites induced an antibody response but failed to induce delayed type hypersensitivity (DTH) to HBsAg.