A series of investigations, recently launched by multiple manufacturers of COVID-19 vaccine candidates, provides reassuring hopes that scientists are on track to develop an effective and safe vaccine at record speed.
On Monday, three research groups separately published early positive results demonstrating that their respective experimental COVID-19 vaccines induced a multiple immune response that may be important for long-term protection against infection.
Those groups included the University of Oxford and its partner AstraZeneca, Pfizer and its partner BioNTech, and the Chinese vaccine company CanSino Biologics. Last week, Moderna also released promising early data.
Experts caution that these early studies, while promising, will need to be confirmed with larger Phase 3 trials, involving tens of thousands of people, to determine if any vaccines could be truly effective.
According to the World Health Organization (WHO), there are at least 23 COVID-19 vaccine candidates who have progressed to various stages of human studies. So far, several of these candidates have shown promising preliminary data from their first clinical trials, either in peer-reviewed journals, directly online to preprint servers, or in press releases.
On Monday, new data from Oxford-AstraZeneca, published in The Lancet, suggested that the vaccine is relatively safe and induces an immune response to combat the new coronavirus. The 1,077 volunteers who received the vaccine in the Phase 1/2 trial developed neutralizing antibodies against COVID-19. These specific antibodies are proteins that fight infections caused by the body and that can prevent the virus from infecting healthy cells. The vaccine also elicited a T-cell response to the virus – another defense method used by the immune system to boost protection and attack cells already infected with the virus.
Professor Adrian Hill, director of the Jenner Institute at Oxford, called the latest data “very encouraging” in an interview with ABC News, adding that experts are “seeing both arms of the immune system being very strongly stimulated by the vaccine.”
Meanwhile, BioNTech and Pfizer also released the results of a Phase 1/2 test on Monday. That study included 60 participants and showed that the vaccine induced both neutralizing antibodies and T-cell responses. The results were published on a prepress server, meaning they have not yet undergone the normal scientific review process.
Also on Monday, CanSino Biologics published data in The Lancet that showed similar results. And last week, the American company Moderna published data in the New England Journal of Medicine that also demonstrated this double effect of neutralizing antibodies and T-cell response.
Francis Collins, director of the National Institutes of Health, told ABC News that many of the vaccines with recently released data look promising.
“Your Phase 1 data looks really good,” Collins said, referring to the Oxford vaccine. “I wouldn’t say it clearly looks better than it does for the Moderna trial or the Pfizer trial. They all look good, which is really encouraging.”
Taken together, these early studies indicate that the four vaccine candidates could confer immunity through multiple pathways to fight COVID-19, although experts caution that more research is still needed.
Dr. Paul Goepfert, director of the Alabama Vaccine Research Clinic at UAB, said that “distinguishing one vaccine candidate from another is very difficult at the moment. They all induce approximately the same number of responses. They all induce one response. neutralizing antibody, which is kind of the gold protection standard for many vaccines. ”
According to Goepfert, the antibodies protect against infection, while T cells, especially a specific subtype known as killer T cells, attack previously infected cells and are very good at preventing disease.
“So, ideally, you want everything. The more the better,” Goepfert said, “the more types of immune responses you can induce with the vaccine, and the greater the number, we think is the best you can have.”
But he cautioned that this is not always the case. Some widely used and effective vaccines, such as the hepatitis B vaccine, do not induce any killer T-cell responses, but remain highly effective.
Although the results reported this week are promising, it is still too early to predict which of the vaccines will be the most effective. The first Phase 1 and Phase 2 studies primarily examine the vaccine’s safety, tolerability, and immune response, but the Phase 3 trials will provide answers to these long-awaited questions about efficacy.
Even Hill admitted that the Oxford team still doesn’t have the data to determine how well their vaccine will actually work. “The truth is, we don’t know when we will have an end result or how well the vaccine works,” Hill said. “It will probably be months. We are targeting September, October … I still think it is a realistic aspiration, but we cannot be sure.”
When it comes to large Phase 3 studies, Oxford is a bit ahead of the pack, having already enrolled more than 10,000 people in Brazil, South America, the UK, and soon in the US.
“Our goal is to vaccinate a total of about 50,000 people in the coming months, so it is promising, but they know that it is not really a race against other vaccines, it is a race against time,” added Hill. “But right now, we are probably ahead in terms of Phase 3 trials and we certainly hope to get a result this year.”
Between vaccination efforts in Europe and North America, Moderna is closely following, slated to begin its Phase 3 trials next week. Similarly, Pfizer-BioNTech is on track to launch its Phase 2/3 trial later this month.
Among Chinese companies, two have already started Phase 3 trials: Sinovac and Sinopharm. According to CanSino Biologics CEO Qiu Dongxu, the company is expected to start Phase 3 trials “soon,” but a clear start date has yet to be released.
Biopharmaceutical companies around the world have now focused their efforts to primarily support the development of COVID-19 vaccines and treatments. Progress has been made at record speeds, and for an unprecedented time, the United States government is taking unprecedented action, increasing the development of some of these vaccines before confirming their efficacy.
According to Dr. Anthony Fauci, the nation’s leading infectious disease doctor, “If everything works as we expect and we don’t get unpredictable potholes and potholes along the way, we should know that as we move through mid to late fall, early winter. , probably late fall, if we have candidates who are really safe and effective. ”
Many scientists and researchers have been working nonstop for the past six months to find a vaccine against COVID-19.
“We feel like there is urgency and pressure really every day,” Hill said. “People work day and night, and we won’t stop until we get a response.”
Eden David, who studied neuroscience at Columbia University and enrolls at the Icahn School of Medicine in Mount Sinai later this year, is a member of the ABC News Medical Unit. Sabina Bera, MD, MS, a psychiatrist in New York, and Shantum Misra, MD, a senior resident in internal medicine at Dartmouth-Hitchcock Medical Center, are contributors to the ABC News Medical Unit.
.
