Nowadays, COVID-19 is getting more serious all around the world. The Agence France-Presse (AFP) reported that the cumulative number of patients with COVID-19 worldwide exceeded 16 million on July 26th. Nearly 75,000 new patients of COVID-19 per day were reported in the United States on July 25th (local time). President Trump admitted that the current situation of COVID-19 infection in the United States was not good, saying the COVID-19 situation would “unfortunately get worse before it gets any better”. The situation in Japan is getting worse, too. A total of 755 patients of COVID-19 were confirmed in Japan on July 26th. Spread all over the country, more than 700 patients have been reported for five straight days. Making the matter worse, the World Health Organization(WHO) has admitted the possibility of the air-borne spread of COVID-19. They stated that “the possibility of near-field air infection cannot be ruled out, especially in certain indoor places where infected people are together, but the place has not been sufficiently ventilated for a long time.” In this situation, many experts pointed out that the only way to overcome the virus is to develop vaccines that target the Corona virus. Therefore, countries around the world are focusing on developing vaccines.
How’s the Vaccine Development Progressing?
According to the WHO, there are more than 130 vaccine candidates being developed, and 23 of them are in clinical trials. Clinical trials are conducted on humans only after their safety is proven through animals. Clinical Phase I confirms drug safety in 20 to 100 healthy adults. In Phase II, 100 to 500 people will be evaluated for proper dosage and usage. Finally in Phase III, 1,000 to 5,000 people will be divided into real drug administration groups with placebo (fake medicine) controls to finally check their safety and effectiveness. After checking the safety and efficiency through these steps, the vaccines will come out to the market. It is known that *AstraZeneca of the U.K, Moderna of the U.S., and CanSino Biologics of China have entered the third phase of clinical trials.
*Companies and research institutes are working together to develop the vaccine. In the text, AstraZeneca collaborated with the Oxford University Research Institute, Moderna with the National Institute of Allergy and Infectious Diseases in the United States, and Cansino with the Institute of Biotechnology of the Academy of Military Medical Sciences.
The vaccine being developed by AstraZeneca is seen as the most promising vaccine by the WHO and the International Vaccine Institute. AstraZeneca announced in the medical journal Lancet on July 20th that early clinical trials of the vaccine induced immune response. This vaccine introduces the Corona 19 gene through the adenovirus (ChAdOx1), triggering a spike protein in the body, causing an immune response. The vaccine is made of a genetically modified chimpanzee cold virus called adenovirus (ChAdOx1), which has few symptoms of infection in humans. AstraZeneca conducted clinical tests on 1,077 healthy adults between the ages of 18 and 55 in Phase I and II and found out that everyone who received the vaccine responded to the antibodies and **T-cell formation in the body. A month after one dose, 91 percent of the drug users were identified as having “neutral antibodies” that neutralized the virus, and a month after two doses, neutralized antibodies were found in all of the drug users. Researchers at AstraZeneca are already conducting a much broader Phase III experiment on thousands of applicants in Britain, Brazil and South Africa. Also, clinical trials for 30,000 people are scheduled to begin in the United States in August.
** T cell is a type of white blood cell that identifies and attacks external intruders, such as viruses. They attack the virus directly or identify and destroy infected cells. This distinguishes it from antibodies that prevent viruses from entering cells.
Moderna is also making efforts to develop vaccines. Their vaccine was the quickest to enter the clinical trial. The researchers have discovered that the Corona virus has a principle of entering the human body by attaching S protein onto human cells. Thus, if this process is interrupted, virus infections can be prevented or slowed down. Usually, S proteins undergo large-scale rearrangement by merging viruses and cell membranes. Researchers have confirmed that the “prefusion conformation S protein”, is likely to be targeted by the vaccine-induced infection-blocking antibodies, a step before infecting the cells. Based on this fact, the Moderna Research Institute has begun designing an ***mRNA vaccine that interrupts the production of S protein. Their clinical trial participants were 45 men and women of various races between the ages of 18 and 55. They were divided into three groups and were given two different doses of vaccines every 28 days, which created antibodies for all test subjects. Moderna is scheduled to enter Phase III clinical trials on July 27th.
*** The mRNA vaccine inhibits viral cloning by preventing surface spike proteins from binding with cells. It also injects genes in antigen areas that induce antibody reactions in the body based on mRNA to induce immune responses in the body.
CanSino Biologics also announced that they have safely derived antibody immune responses from trial vaccination groups. They also use adenovirus, similar with the vaccine of AstraZeneca. The vaccine successfully induced immune response after vaccinating 508 adults once, and confirmed antibodies in 27 out of 36 high-capacity individuals. It is currently conducting Phase III clinical trials for 40,000 people. The countries having clinical trials include Russia, Brazil, Chile and Saudi Arabia.
Is the Vaccine only Beneficial?
There are some things to worry about even when vaccines are being developed. According to the Wall Street Journal on July 26th, the duration of antibodies formed under the vaccine can usually be measured in the second phase of clinical trials. But as the world is engaged in an unprecedented race between drug companies to develop the first vaccine, some procedures have been omitted, and the duration of the antibody effectiveness cannot be verified. Usually, clinical trials should not only observe side effects that occur in a short period of time, but also observe side effects that may occur over a longer period of time. The concern that side effects may occur after commercialization cannot be ignored because the world is now focusing only on quick production and distribution. In addition, in the case of Moderna using mRNA, the results of the clinical trials do not include random testing and are in a very small sample size compared to ChAdOx1, so it is necessary to accept the results with some caution. The biggest problem are concerns about possible side effects. So far, no serious side effects have been reported, only temporary pain in the injection area, headaches, fatigue, chills, fever and muscle aches have been reported, but side effects can be reported again at any time in the future. On the other hand, as in the cases of MERS, if the toxicity of the virus is weakened through mutation before the development period is over, the vaccine development may fizzle out to nothing. Even if the vaccine is commercialized without a problem, the price of the vaccine is already on the rise. The fear is that the exorbitant pricing could lead to the worst-case scenario in which the poor are not even vaccinated.
What Should We Do Now to Keep us Healthy?
Since it is not known when a vaccine will be developed and distributed, it is important to follow the COVID-19 preventative and personal hygiene regulations until then. We have already confirmed through many countries around the world, that the number of patients varies depending on how citizens deal with the recommended preventative measures. Following these regulations, we will keep ourselves healthy and get us one step closer to the end of COVID-19.
Chung Yeongyu ygchung00@naver.com
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