In the early morning of May 18, Moderna, a biotechnology company, revealed the preliminary findings of the highly anticipated Phase I trial of the mRNA COVID-19 vaccine. This information has caused Moderna's share price to soar by more than 20% and fueled Wall Street's rebound.
Despite the overwhelming response to this news, the purpose of all Phase I trials is mainly to prove safety and tolerability. Although the early results are encouraging, Moderna ’s undisclosed content raises some questions.
I am a data scientist. Until last month, he had been developing vaccines for Zika and Dengue. Since the beginning of the COVID-19 pandemic, I have taken the lead in establishing an alliance of more than 100 cancer centers to collect data about cancer patients infected with COVID-19. The purpose of COVID-19 and the Cancer Society is to quickly collect and disseminate information about this particularly vulnerable group. With a background in vaccine development, I found that Moderna ’s press release lacked some key details.
What is a vaccine?
A vaccine can mimic an infection, making it easier for the immune system to understand the disease. After Edward Jenner proved in 1796 that vaccination with low-toxic vaccinia can prevent smallpox, vaccination became a public health tool. After his son died of smallpox, Benjamin Franklin regretted his decision not to vaccinate his son. Today, vaccines are widely considered to prevent and eradicate many once-frightening deadly diseases.
Vaccines prepare the immune system by producing disease-resistant proteins called antibodies, and if real infectious viruses appear, they will seek and attack.
Traditional vaccines against viruses are either weakened versions of the entire virus that cannot cause disease; or they are made from characteristic viral proteins called antigens and then trigger an immune response. The antigen in the new coronavirus SARS-CoV-2 is the coronary spike (S) protein, through which the virus can be locked in the lungs and respiratory cells.
However, because it is difficult to mass produce pure proteins on medical standards, the development of vaccines based on viral proteins is a slow process. But now scientists have developed another vaccine: the mRNA vaccine.
The researchers did not provide humans with protein vaccines, but instead provided them with mRNA, which is the biological code that cells read and translate to produce their own proteins. Therefore, instead of the traditional viral protein vaccine, the mRNA vaccine provides a synthetic copy of the mRNA encoding a single protein in the virus, which the host uses to produce the viral protein itself. Like other vaccines, the presence of this protein also activates the body's immune system against viruses.
A major advantage of mRNA vaccines is that scientists can directly inject molecular instructions to make proteins, thereby skipping the protein production in the laboratory and entering the body itself.
Lessons learned from previous keratovirus epidemiology
based on Moderna Inc. of Massachusetts has rapidly developed and tested the experiment The COVID-19 mRNA vaccine is called mRNA-1273. The collaborators of the National Institute of Allergy and Infectious Diseases (NIAID) are already studying the experimental Middle East Respiratory Syndrome (MERS) vaccine, which targets a spike protein closely related to coronavirus. Therefore, once the genetic sequence of SARS-CoV-2 is available, Moderna and its collaborators at NIAID seize the opportunity.
Moderna has up to US $ 483 million in federal funds to accelerate the development of coronavirus vaccines, and began testing the 2019-nCoV vaccine (mRNA-1273) on February 25, 2020.
The first phase of the research study is a vaccine led by NIAID, part of the National Institutes of Health (NIH), designed to assess the safety, tolerability, and induction of immune responses at three dose levels of 25, 100, or 250 micrograms Ability.
On May 18, Moderna announced interim data for the first phase. In general, mRNA-1273 is safe and well tolerated, but it is slightly red and swollen at higher doses.
During the six-week study, no volunteers encountered any life-threatening events.
In all 45 volunteers (18 to 55 years of age), antibodies produced by mRNA-1273 can bind the target spike protein at each injected dose. The production of a binding antibody response from mRNA-1273 injection was similar to that found in patients who recovered from previous SARS-CoV-2 infection. It is important to emphasize that, despite this, even among the survivors of COVID-19, the antibody response is highly variable.
This is unconventional for scientific research, only neutralizing antibodies from eight 45 volunteers-four volunteers in 25 and 100 microgram doses, respectively.
Neutralizing antibodies are essential for effective long-acting vaccines because they not only bind to the virus but also prevent infection. The age of the eight volunteers is unknown. This is important information because COVID-19 is much more deadly for elderly patients. It is important to know whether this immune response is limited to young participants.
In addition, neutralizing antibody responses in the remaining 37 volunteers were not disclosed. Therefore, it is impossible to know whether mRNA-1273 is invalid for them, or whether the results cannot be obtained at this time.
Phase 2 trial of mRNA-1273 has been approved by the US Food and Drug Administration. In this trial, each subject will receive two vaccinations-the first and booster vaccinations-28 days apart, with 50 mg or 250 mg of placebo, respectively.
Modified choices for higher doses indicate that the lowest 25 microgram phase 1 dose is not very effective. Moderna expects that the third phase of trials will begin in July and is expected to produce 1 billion doses of vaccine shortly thereafter.
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Sanjay Mishra, project coordinator and staff scientist at Vanderbilt University Medical Center, Vanderbilt University
This article has been based on The Creative Commons license was republished from The Conversation. Read the original article.