Diagnosis of COVID-19 for controlling the pandemic: A review of the state-of-the-art.

To date, health organizations and countries around the world are struggling to completely control the spread of the coronavirus disease 2019 (COVID-19). Scientists and researchers are developing tests for the rapid detection of individuals who may carry the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), while striving to find a suitable vaccine to immunize healthy individuals. As there are clinically reported cases of asymptomatic carriers of SARS-CoV-2, fast and accurate diagnosis plays an important role in the control and further prevention of this disease. Herein, we present recent technologies and techniques that have been implemented for the diagnosis of COVID-19. We summarize the methods created by different research institutes as well as the commercial devices and kits developed by companies for the detection of SARS-CoV-2. The description of the existing methods is followed by highlighting their advantages and challenges. Finally, we propose some promising techniques that could potentially be applied to the detection of SARS-CoV-2, and tracing the asymptomatic carriers of COVID-19 rapidly and accurately in the early stages of infection, based on reviewing the research studies on the detection of similar infectious viruses, especially severe acute respiratory syndrome (SARS) coronavirus, and Middle East respiratory syndrome (MERS) coronavirus.

Optimized dose of synthetic analogues of Monophosphoryl lipid A as an effective alternative for formulating recombinant human papillomavirus vaccine.

Adjuvants are a crucial component of recombinant vaccines such as the human papillomavirus (HPV) vaccine. Monophosphoryl lipid A (MPL) extracted from Salmonella Minnesota lipopolysaccharide is used as an adjuvant for the HPV vaccine. Due to the limitations in accessibility and reproducibility of MPL, investigating synthetic analogues of MPL (synMPL) is urgently needed to overcome these limitations. In this study, female BALB/c mice were vaccinated by HPV vaccine formulated with synMPL and aluminum hydroxide gel in which the concentration of synMPL ranged from 0 to 100 µg/dose. Anti-HPV L1 VLP antibody was measured for each group through Indirect ELISA and compared with Cervarix and Gardasil vaccines as approved anti-HPV vaccines. SynMPL showed a concentration-dependent increase up to 50 µg/dose in the immunogenicity of the vaccine. Therefore, synMPL at concentration of 50 µg/dose was selected as optimum concentration. The GMT profiling of synMPL-formulated vaccine (named Papilloguard) and Cervarix was not statistically different (Mann-Whitney test). The Gardasil vaccine showed 10-fold lower GMT for anti-HPV 18 L1 VLP antibody but anti-HPV 16 L1 VLP antibody was similar to Cervarix and Papilloguard. The current findings suggest that the synMPL in combination with aluminum hydroxide could be used as a potential adjuvant candidate for human vaccine.

Immunogenicity of HPV and HBV vaccines: adjuvanticity of synthetic analogs of monophosphoryl lipid A combined with aluminum hydroxide.

Monophosphoryl lipid A (MPL), a purified and detoxified product of lipopolysaccharide (LPS) of Salmonella minnesota R595, has been used as an adjuvant in different vaccines. In this study, the efficacy of human papillomaviruses (HPV) and hepatitis B virus (HBV) vaccines formulated with aluminum hydroxide combined with two different synthetic MPLs, 3D-(6-acyl)-PHAD or 3D-PHAD, or aluminum hydroxide combined with the mixtures of such MPLs, has been assessed. The immunogenicity in female BALB/c mice was verified by two intramuscular injections of differently formulated HPV and HBV vaccines and the total immunoglobulin G (IgG) antibody response was considered to compare the employed adjuvants. As verified experimentally, a mixture of 3D-(6-acyl)-PHAD and 3D-PHAD was able to induce significantly higher antibody titer than that of either 3D-(6-acyl)-PHAD or 3D-PHAD, when used individually. Interestingly, based on the responses achieved in terms of the total antibody levels, such mixture of synthetic MPLs was found to be even more effective than the bacterially derived MPL. Accordingly, the obtained results indicated that, if designed appropriately, synthetic MPL molecules could provide improved adjuvanticity with high level of consistency.