The anticipation for the COVID-19 vaccines in development is soaring as a number of global pharmaceutical companies have announced successful clinical trial results. The health authority and the public would closely follow the vaccines’ further development to confirm their effect, safety and reasonable pricing.

▲The COVID-19 vaccine candidates currently in Phase III trial

Total 11 candidate vaccines have initiate their Phase III clinical trials globally, categorized in three major types of mRNA, virus vector and inactivated vaccine.

BNT162, in development by Pfizer and BioNTech, and mRNA-1273 by Moderna are mRNA vaccines. Instead of an attenuated vaccine that reduces virulence for the injection, mRNA vaccine uses mRNA strand from a virus to manufacture the vaccines fast.

On the contrary, AstraZeneca, Janssen, Gamaleya (Russia) and CanSino Biologics (China) are developing viral vector vaccines. The type of vaccine injects viral vector to transport the viral gene. AstraZeneca’s candidate vaccine uses chimpanzee adenovirus-based vector to combine the spike-like protrusions on COVID-19 virus.

Moderna has also applied for the use approval on Nov. 30 in the U.S. and EU for its 100-percent effective vaccine proven through Phase III trial findings. The U.S. Food and Drug Administration (FDA) scheduled the vaccine approval review on Dec. 11 and 17 for Pfizer and Moderna, respectively.

▲Clinical results for each vaccine disclosed but AstraZeneca leaves questionable findings

On Nov. 23, AstraZeneca presented the results of Phase II/III on its developing vaccine AZD1222. The clinical protocol was to confirm the COVID-19 prevention effect shown two weeks after two doses of vaccine administered in one-month interval on 10,000 volunteer subjects aged 18 and over.

The trial found the vaccine was 90 percent effective in 2,741 subjects who were administered with a half-dose, whereas it was 62 percent effective in 8,895 subjects who had a full-dose. Total 131 subjects were reportedly infected with the virus.

AstraZeneca claimed the vaccine is average 70 percent effective by combining the two trial findings from 11,636 volunteers. Apparently, the company had no reports of severe adverse reaction.

The medical experts are clashing over the AstraZeneca’s vaccine; they are conflicted over the facts that the half-dose was more effective and the company insisting on the average efficacy deducted from using two different doses. Also the experts are suspecting the use of half-dose could have been an unintentional error in the trial.

An insider from the Korean Society of Infectious Diseases (KSID) commented, “It is odd to calculate average by adding the results from two different dose groups, but also we are questioning the credibility in the efficacy data extracted from only 2,741 people. FDA requires data analysis from at least 30,000 people.”

Regarding the skepticism, Dr. Kim Woo-joo at Korea University Guro Hospital Department of Infectious Disease said, “A half-dose vaccination showing higher efficacy is an exceptional result. A lot of news media is reporting it as an error, but a clinical trial cannot possibly have such error.”

▲mRNA vaccine competition, Moderna 94.5% vs. Pfizer 95%

An interim analysis of Moderna’s COVID-19 vaccine Phase III COVE study was announced on Nov. 16. The protocol targeted 30,000 people administering two doses in four-week interval to confirm the COVID-19 infection after two weeks.

In the first interim analysis, total 95 people were infected, including 90 people receiving placebo and five people receiving the mRNA vaccine. The vaccine was 94.5 percent effective. The reports on the adverse reactions were of mild cases, such as pain around the injected area and fatigue.

The second endpoint was the number of COVID-19-infected people after using the vaccine. The placebo group had a total of 11 severe cases, but none of the mRNA vaccine group reported a severe case. Based on the findings, Moderna claims their vaccine is 100-percent effective against severe case of COVID-19.

Pfizer administered two doses of their vaccines on 43,661 people in 21-day interval. Total 10 cases were confirmed with the virus, where nine were from the placebo group and one was from the vaccine group. Analyzing the result, the company states the vaccine is 95-percent effective. The vaccine had no reports of adverse reaction so far.

Dr. Kim Woo-joo mentioned, “In regards to the efficacy, Moderna and Pfizer’s vaccine demonstrating 94.5 percent and 95 percent efficacy is outstanding. Now the problem is distribution of these vaccines.”

▲Taking account of cost-effectiveness, which could be accessible from South Korea?

The experts say all three vaccines are over 90-percent effective, if they were to directly quote AstraZeneca with their 90-percent effective vaccine trial result.

However, the three vaccines have widely contrasting distribution methods and pricing.

First, Pfizer’s vaccine requires to be stored at minus 70 degrees Celsius. The vaccine is priced at USD 19.50 (approximately 21,600 won) per dose (requires two-dose administration). And as the vaccine distribution would need a cold chain to maintain the minus 70 degrees Celsius, the actual administration cost would be much higher.

Considering South Korean flu vaccine distribution struggled to maintain 2 to 8 degrees Celsius, distributing Pfizer’s vaccine soon may be out of question.

The Ministry of Food and Drug Safety (MFDS) official commented, “Pfizer’s COVID-19 vaccine requires an ultra-cold chain to deliver them at minus 70 degrees Celsius. It is questionable a company in South Korea would be able to handle mass distribution of Pfizer vaccine in such challenging environment.”

Moderna vaccine, on the other hand, has to be stored at minus 20 degrees Celsius. As normal refrigerated distribution is kept at around minus 20 degrees Celsius, the vaccine distribution would be more manageable by private companies. But the issue is its pricing. Moderna says it would be priced at 32 to 37 dollars, or approximately 35,500 won to 41,000 won. For the two-dose administration, it would cost more or less 80,000 won.

Meanwhile, AstraZeneca’s vaccine can be distributed at around 2 to 8 degrees Celsius and is priced at around 4 dollars per dose (approximately 4,400 won). The experts argue the vaccine would be most preferred with the cost of about 10,000 won for two-dose administration.

Regardless of the emergency approval given to the vaccine in other countries, the company would be able to start the distribution in the first quarter next year at earliest as it would need to wait for the MFDS approval, vaccine procurement contracting and manufacturing.

MFDS official added, “We would have to wait and see first if the actual vaccination result would match its clinical finding, as it started its emergency use approval application procedure in other countries. If AstraZeneca can prove the low-dose vaccine efficacy through additional clinical trials, their vaccine would be most adequate to be used in South Korea.”