Vaccine experts say, “There are animal tests that show that it works, but in humans, well.”
Clinical experts say, “More scientific evidence that mixed vaccination is effective”
It is controversial that the UK has declared that it will mix and use the Corona 19 vaccine like a bomb stock in an emergency. Corona 19 vaccine is usually divided into 1st and 2nd doses, but if the same product as the first dosed vaccine cannot be obtained in a pandemic situation, another company’s vaccination will be permitted at the second dose. Domestic experts are in the position that the British policy has a point, but since there is no evidence in the human body, more scientific evidence should be presented.
According to the COVID-19 vaccination guidelines released on the 31st of last month by the UK’s England Department of Public Health (PHE), if the first vaccination vaccine cannot be obtained at the time of the second vaccination, or if the manufacturer of the vaccine administered at the first vaccination cannot be identified, it can be obtained nearby. It is recommended that the vaccine should be given. In the UK, Pfizer vaccine and AstraZeneca vaccine are currently approved, and both vaccines require a second dose after 3 to 4 weeks to maximize efficacy.
For example, if the Pfizer vaccine is not available at the time of the second vaccination after receiving the Pfizer vaccine at the first vaccination, it is better to get the AstraZeneca vaccine quickly rather than waiting for the same vaccine.
British health officials drew the line that this method is a dilemma that can only be used in emergency situations. A PHE official said, “A related study is ongoing, but there is still no evidence for the interchangeability between the Corona 19 vaccines.”
A domestic vaccine expert analyzed that the UK’s choice also had a reasonable factor.
Both vaccines currently approved in the UK use a method of inducing antigen generation and antibody formation in the body by transmitting genetic information about the virus’s spike protein, but the difference between the two vaccines differs in the delivery method that carries the genetic information. The Pfizer vaccine transfers information through lipid-enclosed mRNA, while the AstraZeneca vaccine uses chimpanzee adenovirus as a carrier (vector).
“In theory, mixing vaccines from different platforms may improve efficiency,” said Jae-Hwan Nam, a member of the Vaccine Introduction TF (Task Force) member of the Department of Medical Life Science. “Prime boost), but if different platforms are used for the first and second vaccinations, the interference effect between vaccines can be avoided and the antibody induction effect can be improved.”
However, Professor Nam pointed out that it is a weakness that this phenomenon has not yet been proven to’people’. Professor Nam said, “The heterologos prime boost phenomenon has been proven several times in animal experiments. I also wrote a related paper,” he said. “However, in principle, it is correct to obtain a separate license through a new clinical trial to use this method in humans.”
“In fact, it is rare for a single infectious disease to have a vaccine on multiple platforms. In the case of flu, there are vaccines from several companies, but the platform is the same as an inactivated vaccine that neutralizes the antigen.” He added, “Because the current Corona 19 situation is urgent, we are using such a hurdle.”
If so, how should we decide whether to use vaccines in a similar situation in Korea?
A domestic clinical expert recommended that the minimum scientific evidence should be secured first. A clinical specialist who requested anonymity said, “In fact, if there is accurate data on the ability to generate neutralizing antibodies, we can confirm it based on this, but in the case of AstraZeneca, clinical trials have not yet been completed, and the Pfizer vaccine has not yet been published in public. “In this situation, the UK government has a flexible approach to supplying vaccines,” he said.
“However, it is regrettable that the scientific basis for flexibility is lacking. PHE is an institution with its own rationality, but it did not reveal on what basis the policy was decided. “There should be a result of comparing the properties of antigenic proteins induced by AstraZeneca and Pfizer vaccines. If the two antigens are similar, it can be assumed that similar antibodies can be induced to amplify antibody production. The Korean government should also secure such a minimum scientific basis and then decide whether to mix vaccinations.”
On the other hand, some analyzes say that the UK’s policy of blending vaccines is a skirmish caused by the UK’s unique stiff medical system.
The previous specialist said, “In the case of the UK, the medical system is not developed with regional hospitals as in Korea, and most of them are operated in a way that relies on public health care. It means that the institutions that have the vaccine are limited.” In addition, the UK is currently experiencing an explosion of Corona 19. “If the patient suddenly becomes concentrated, the supply and demand of vaccines may not be smooth depending on the local hospital, so this policy was devised, but it is not suitable for the nationality of Britain, which is in the ranks of advanced countries,” he explained.
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