Pfizer’s Protease Inhibitor New Drug Development for SARS-CoV-2 for 2021 Looks Promising

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By Lawrence Jones, PhD

Protease inhibitor technology used commonly as a strategy to treat HIV and hepatitis C is now a strategy for SARS-CoV-2 antiviral therapy development. Researchers for SARS-CoV-2 have focused on “main protease (Mpro) which plays a dominant role in processing CoV-encoded polyproteins which mediate the assembly of replication-transcription machinery and is thus recognized as an ideal antiviral target (Cui, et. al, 2020.” The SARS-CoV-2 antiviral therapy development may consist of repurposed drugs as the push for a breakthrough is not only a goal by Pfizer but other biopharma companies in pursuit. “The first protease inhibitor to be approved by the US Food and Drug Administration (FDA) was saquinavir, in December 1995, and within months, two other protease inhibitors, ritonavir, and indinavir were approved (Cully, 2018).”

So far, Pfizer has been able to deliver to the public. Thus, the company has been a significant player during the SARS-CoV-2 vaccine production and distribution with effective outcomes regarding their vaccine efficacy and ability to produce the quantity of vaccine needed. Pfizer’s protease inhibitor outlook for the first U.S.-approved SARS-CoV-2 therapeutics is fast-tracked to their initial clinical phase 1 trial. Pfizer’s early stage one clinical trial on an oral antiviral therapy that can treat a SARS-CoV-2 patient effectively is now on the horizon. The quest to get the SARS-CoV-2 pandemic under control is continuing with urgency and caution.

The aim of the drug is for the first developing symptoms, which according to Pfizer (March 23, 20201), would make it the first oral antiviral treatment of its kind for coronavirus. Pfizer (March 23, 2021) “the trial is randomized and includes placebo groups with both single and multiple-dose studies.” What is promising is that the Pfizer company “is also studying an intravenous antiviral to treat SARS-CoV-2, which will become an option for some hospitalized patients over time.” Pfizer’s “PF-07321332 “protease inhibitor” has been formulated to attack the “spine” of the SARS-CoV-2 virus and stop it replicating in our nose, throats, and lungs.”

Pfizer’s Chief Scientific Officer, Mikael Dolsten reports that he is hopeful that their early raises the prospects of a cure for future pandemic threats. For now, laboratory “invitro” for animal tolerance is of the foremost importance before being tested in humans. Clinical trials will be intensive, and the screening and dosing steps and outcomes of the dosing step will be crucial for determining the drug’s safety and tolerability. The upcoming months of 2021 and early 2022 look very promising for technology combination therapies to mitigate SARS-CoV-2 infections.


Butz, B. (March 23, 2021). Pfizer launches trial for novel oral SARS-COV-2 therapeutic.

Cui, W., Yang, K., & Yang, H. (2020). Recent progress in the drug development targeting SARS-CoV-2 main protease as treatment for COVID-19. Frontiers in molecular biosciences,

Cully, M. (November 28, 2018). Protease inhibitors give wings to combination therapy.

Holzberg, E. (March 23, 2021). Pfizer Testing A Pill To Treat Covid. Pfizer Testing A Pill To Treat Covid (

Lucy, P. (April 28, 2021). Pfizer CEO says oral SARS-COV-2 pill could be ready by the end of the year.

Pfizer (March 23, 2021). Pfizer initiates phase 1 study of novel oral antiviral therapeutic agent against sars-cov-2.

The Quest for Universal Vaccines

Blog Post by: Lawrence Jones, Ph.D.

Universal vaccines may be a game changer for future infections. Researchers say a universal flu vaccine could be within reach sooner rather than later, although though it may be years before a vaccine is ready for human use (Farzan, 2020).Farzan (2020) mentions on National Public Radio (NPR) that: “in the future, one vaccination for a given pathogen could provide protection from multiple flu strains, and perhaps last longer than a single season.” Routh (April 3, 2019) reported last year that the first clinical trial of an innovative universal influenza vaccine candidate was successfully initiated and the main effort for now is to assess the vaccine’s safety and tolerability.

Ultimately, the objective is the vaccine’s ability to induce an immune response in healthy volunteers. The CDC (2020) estimates that the flu shot reduces your risk of getting infected by 40% to 60%, assuming the statistically determined strains for the upcoming season match the vaccine. The end of the school year for many schools across the United States will take place withinthe next week or so. Many discussions and strategies are already in the planning phase for face-to-face school interactions in the fall, as it reflects the various phases of easing state restrictions pertaining to COVID-19 containment. What will the fall look like for student and employee health?

Currently, influenza vaccinations records are, in most instances, a requirement for a child’s health profile. The 2021-2022 school year in the United States may be the first year where there may be real promise of a COVID-19 vaccine. Although a vaccination for COVID-19 is still six to 12 months away, the discussion of a universal vaccine has become even more important. A universal SARS vaccine for combatting future outbreaks and coronavirus infections will be ideal. Severe acute respiratory syndrome coronavirus (SARS-CoV-1) is a contagious and sometimes fatal respiratory illness that was identified about 18 years ago and it looks like it is here to stay.

For most day care facilities, elementary and secondary schools, most likely, health updates and school records will require certain health standards as they pertain to vaccination records, necessary for school enrollment and employment. Conventional influenza vaccines are designed to stimulate distinct neutralizing antibodies to attack highly variable hemagglutinin antigens. Sometimes these seasonal vaccines are suboptimal for rapidly changing influenza viruses. Nevertheless, some protection is needed and new technologies for developing influenza vaccines are on the horizon. Achieving a consensus among scientists and health professionals on a common definition, “including scope of protection and clinical endpoints, may help to focus research efforts.”

The National Institute of Allergy and Infectious Diseases, a branch of the NIH, says it will likely be another 10 to 15 years before a universal flu vaccine is on the market.Vaccines for smallpox, mumps and rubella are longer lasting but the changes and mutations in influenza and now SARS-CoV-2 will be a tough battle. Given the current need, is it likely that a universal SARS vaccine may be available before a universal flu vaccine?


Farzan, S. (February 27, 2020). Researchers Step Up Efforts To Develop A ‘Universal’ Flu Vaccine. National Public Radio.

Ostrowsky, J., Arpey, M., Moore, K., Osterholm, M., Friede, M., Gordon, J., … & Bresee, J. (2020). Tracking progress in universal influenza vaccine development. Current Opinion in Virology, 40, 28-36.

Routh, J. (April 3, 2019). NIH begins first-in-human trial of a universal influenza vaccine candidate. National Institutes of Health.

Reprint from the Hopkins Biotech Network:

​Using Aptamers in Vaccine Innovation for 2020

Blog Post by: Lawrence Jones, Ph.D.

In these times of the COVID-19 pandemic there is a race to find cures and vaccines throughout the world get control of the viral threat. According to Marketwatch (April 9, 2020) they report that 21 companies are working tirelessly on coronavirus treatments or vaccines. I am not going to review those 21 company vaccine efforts however, the link below in the references has been provided. More so I am touching on the use of aptamers in vaccine development and pharmaceutical therapy in times such as this. With time being of the essence for faster production of vaccines and other pharmaceuticals, aptamer use in vaccine technology has emerged among topics of discussion. From what I understand, aptamer technology has been around for decades but in the recent decade it was been used more in the development of vaccine technology.

The use of aptamers has attracted the attention of many scientists that are seeking customized ways that would otherwise takes perhaps a year or years to develop in an antibody production. “Aptamers are oligonucleotides, such as ribonucleic acid (RNA) and single-strand deoxyribonucleic acid (ssDNA) or peptide molecules that can bind to their molecular targets with high affinity and specificity due to their specific three-dimensional structures”( Song, 2012). Aptamers have all the general advantages of antibodies, but also have benefits of thermal stability, low cost production, and increasingly unlimited applications. Aptamers are known as alternatives to antibodies. Lui and associates (2020)point out in their recent publication that there are “two Korean patents that describe the use of RNA aptamers for inhibition of SARS viruses: patent (1) application (KR2009128837) identifies RNA aptamers as anti-SARS agents capable of binding to and inhibiting the double-stranded DNA unwinding of the SARS virus helicase; patent (2) application (KR 2012139512) describes RNA aptamers with distinct affinity for the nucleocapsid of SARS-CoV for potential pharmaceutical use.

Numerous analytical techniques, such as electrochemical, colorimetric, optical, and mass-sensitive methods, can be utilized to detect targets, due to convenient modifications and the stability of aptamers. Finally, several medical and analytical applications of aptamers are presented. In summary, aptamers are promising materials for diverse areas, not just as alternatives to antibodies, but as the core components of medical and analytical equipment

“Aptamers usually consist of 15 to 50 nucleotides and have an molecular weight ranging from 5 to 15 kDa.37” (Kaur, et. al, 2018). They have a low immunogenicity because nucleic acids are generally not recognized by the human immune system.Hidding (2016) points out that disadvantages of aptamers may be solved by using antibodies instead and choosing both in combination with aptamers in order to get synergistic effects could amplify each other’s strengths(p.17). Combinations of the two during this covid-19 viral threat could result in very promising therapeutics. Aptamers are an alternative to antibodies in many biological applications based on the literature.I highly encourage reading more about apatamers. More to come about the applications in the upcoming months and years.


Baird, G. (2014) .Application of Aptamers in the Clinical Laboratory - Geoffrey Baird, MD, PhD

Hidding, J. (2016). A therapeutic battle: Antibodies vs. Aptamers. Nanoscience master program, 1-20.

Kaur, H., Bruno, J. G., Kumar, A., & Sharma, T. K. (2018). Aptamers in the therapeutics and diagnostics pipelines. Theranostics, 8(15), 4016.

Lee, J. (April 9. 2020).These 21 companies are working on coronavirus treatments or vaccines here’s where things stand.

Liu, C., Zhou, Q., Li, Y., Garner, L. V., Watkins, S. P., Carter, L. J., ... & Albaiu, D. (2020). Research and development on therapeutic agents and vaccines for COVID-19 and related human coronavirus diseases.

Reinemann, C., & Strehlitz, B. (2014). Aptamer-modified nanoparticles and their use in cancer diagnostics and treatment. Swiss medical weekly, 144(0102).

Song, K. M., Lee, S., & Ban, C. (2012). Aptamers and their biological applications. Sensors, 12(1), 612-631

Wolter, O., & Mayer, G. (2017). Aptamers as valuable molecular tools in neurosciences. Journal of Neuroscience, 37(10), 2517-2523.

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