Five technical routes for COVID-19 vaccines. The recombinant protein vaccine , which Dr. Tao has been optimistic about, is finally on the market.
On Monday, the European Commission approved the COVID-19 vaccine Nuvaxovid of the US company Novavax (Novavax) for use throughout the EU . The latter is the fifth official vaccine approved by the EU.
Nuvaxovid is a recombinant protein vaccine. Recombinant protein technology is commonly used in conventional vaccines, such as hepatitis B vaccine , hepatitis E vaccine, cervical cancer vaccine , and some influenza vaccines. Compared with adenovirus vector technology and mRNA technology, recombinant protein technology has been tested for a long time, and its safety and effectiveness can be assured.
EU officials hope that recombinant protein vaccines, which are more traditional than newer technologies, will help persuade those hesitant to get vaccinated to come forward and take them.
Nova is a US company. Nuvaxovid has currently received emergency use approval in Indonesia and the Philippines. Japan has agreed to purchase 150 million doses of the vaccine, while also supplying goods to the United Kingdom, India, Australia, New Zealand , Canada and the World Health Organization. submitted an application for approval. However, there is a slight embarrassment: in the United States, although Novavax has applied to the FDA, its production and vaccine review processes have been plagued by delays.
Unlike Pfizer and Moderna's mRNA vaccines, Nuvaxovid does not require ultra-low temperature storage, giving it a clear advantage in terms of operability and cost of cold chain logistics .
In addition, commonly used recombinant protein vaccines mostly use traditional aluminum adjuvants, but Nuvaxovid uses Novavax's innovative adjuvant - Matrix-M, a saponin from the South American saponaria tree.
Matrix-M adjuvant can strongly stimulate the immune system, so the immune effect of this vaccine is better than that of traditional aluminum adjuvant vaccines. It is like the protagonist of a video game using a plug-in to enhance it. Dr. Tao jokingly called it: a cheating version of the recombinant protein vaccine. However, the strong stimulation leads to more adverse reactions than traditional aluminum-adjuvanted vaccines.
All current inactivated COVID-19 vaccines and recombinant protein COVID-19 vaccines for emergency use in my country use traditional aluminum adjuvants, so they are very safe.
The EU’s approval of Nuvaxovid is a major progress for Nuvaxovid and a big step forward for recombinant protein vaccine technology.
China’s recombinant protein vaccine - Zhikweide (Zhifeilong Kema Company), although it is the world’s first large-scale use of recombinant protein vaccine (approved for emergency use in China at the end of March, it was also approved in Uzbekistan Approved for marketing and approved for emergency use in Indonesia), but more applications and international recognition are needed.
The EU is a large market with 27 member states and a population of nearly 500 million. Nuvaxovid's victory in the EU means that the recombinant protein vaccine technology has received heavyweight recognition (although it has not yet been approved for emergency use in the United States and the World Health Organization).
So, in the face of the menacing Omicron mutant strain (jokingly called the Big Devil), does the recombinant protein vaccine perform well?
Let’s talk about Nuvaxovid first.
Novavax released the results of the Nuvaxovid antibody study against Big Devil on its official website on December 22 (http://t.cn/A6xdoUam):
After 2 regular doses of Nuvaxovid, the neutralizing antibody level against Big Devil It is more than 4 times lower than the neutralizing antibodies against the original strain.
A booster dose was given about 6 months apart from the second dose of Nuvaxovid. The levels of neutralizing antibodies against the original strain and the big devil were 5.4 times and 9.3 times higher than those after the second dose, respectively.
Glenn, President of Nova's R&D, said: Nuvaxovid has shown a strong immune response against the devil and other mutant strains... This shows that Nuvaxovid can play an important role in the continued fight against new mutant strains.
let’s talk about Chikweide.
Before, Dr. Tao introduced that the South African hypermutated strain was coming fiercely. Zhang Wenhong’s allogeneic booster study on the vaccine came at the right time. He also introduced that three shots of the mRNA vaccine were able to suppress the big devil, reminding China: Variants with higher antibodies. Source enhancement is very important, and they are all research on my country's recombinant protein vaccine Chikvaide against the big devil.Today, Dr. Tao will introduce to you two more studies, respectively from Zhang Wenhong's team and Institute of Microbiology, Chinese Academy of Sciences team.
The research results of Zhang Wenhong's team have been officially published in Emerging Microbes & Infections on December 22, as follows:
http://t.cn/A6xdKZDJ
Main findings:
Bad news: Vaccination with the second dose of Sinopharm Beisheng Inactivation Fourteen days after vaccination, the levels of neutralizing antibodies against other strains ranged from 8.9 to 67.4, while the neutralizing antibodies against the big devil were undetectable in 8 out of 10 people.
Good news: People who had received 2 doses of Sinopharm Beisheng inactivated vaccine 6 months ago were tested on the 14th day after the booster immunization. The same vaccine booster group or Zhikweide booster group had significant neutralizing antibodies against Big Devil. The increases, from almost undetectable to 48.7 and 95.9 respectively, were increased to 108.7 in neutralizing antibodies in the ChicVide booster group on day 28.
However: the neutralizing antibody titers of the two vaccines against Big Devil are not as good as those against the original strain. After booster immunization, the level of neutralizing antibodies against Big Devil is only 6.7% to 17.1% of that of the original strain.
Main conclusion: Two doses of inactivated vaccine cannot protect against the big devil. Only the third dose of booster can withstand the big devil. The level of neutralizing antibodies boosted by the recombinant protein vaccine is better than that of the inactivated vaccine.
The results of the Institute of Microbiology, Chinese Academy of Sciences team were published online on biorxiv. It is not officially released yet, but it is very worthy of reference. This study has given us some new knowledge about the pattern of the devil's antibody response in 4 groups of people. The vaccine groups are all compared based on 3 doses. Each of these four groups has 16 people, namely: natural infection recovery group, inactivated vaccine group (3 doses, 0.16 intervals), short-interval recombinant protein vaccine group (3 doses, 0.12 intervals) and long-interval recombinant protein vaccine group Vaccine group (3 doses, 015 intervals).
http://t.cn/A6x1NVGf
Main findings:
Long interval is better than short interval (picture below): Whether it is against the original strain or the big devil, the IgG antibody level of the long interval recombinant protein vaccine group is higher than that of the short interval In the spacer group, the IgG antibodies against Big Devil are lower than those against the original strain, which shows that Big Devil's ability to escape the current vaccine is indeed very high. The Big Devil IgG antibody in the short-interval recombinant protein vaccine group seems to be lower than that in the inactivated vaccine group. Since the interval between the second and third doses of the inactivated vaccine is 5 months, it can be considered that the long interval has an advantage over the short interval again.
The long-interval recombinant protein vaccine group had the highest neutralizing antibody positive rate: the infection recovery group, inactivated vaccine group, short-interval and long-interval recombinant protein vaccine groups had the highest neutralizing antibody positive rates of 6.3% (1/ 16), 62.5% (10/16), 56.3% (9/16) and 100% (16/16). The
long-interval recombinant protein vaccine group has the smallest decrease in neutralizing antibodies of Daemon (picture below): for the five virus strains, the neutralizing antibodies of Dabo are the lowest; compared with the neutralizing antibodies of the original strain, the infection recovered The reduction proportions of neutralizing antibodies in the group, inactivated vaccine group, short-interval and long-interval recombinant protein vaccine groups were 94.2%, 80.3%, 90.6% and 67.7% respectively.
The recombinant protein vaccine group has a great advantage over the Delta strain: If you don’t look at the bad devil, but the Delta strain currently making waves in the country, then the neutralizing antibodies of the two recombinant protein vaccine groups are higher than those of the inactivated vaccine , the neutralizing antibody titer against Delta in the long interval group was 12.5 times that of the inactivated vaccine (2133 Vs 171), and 1/3 higher than the neutralizing antibody against the original strain (2133 Vs 1599).
Main conclusion: Regardless of recovery from infection or vaccination with 3 doses of inactivated vaccine or recombinant protein vaccine, the neutralizing antibodies against the big devil decreased significantly, among which 3 doses of recombinant protein vaccine with long interval performed the best. For the neutralizing antibodies of the Delta strain, 3 doses of recombinant protein vaccine with long intervals are far better than the inactivated vaccine.
Dr. Tao's point of view:
The big devil poses a serious challenge to the protective effect of various vaccines currently in use. Two doses are definitely not enough. Three doses can temporarily suppress it, but it is hard to say how long it can be suppressed. If we consider containing the Delta strain, then the neutralizing antibodies of 3 doses of the recombinant unilateral vaccine have a crushing advantage over the inactivated vaccine, and there is no doubt that the protective effect is better.
Any efforts to improve the protective effect are worthy of priority, including long-interval vaccination of 3 doses of recombinant protein vaccines, and boosting with vaccines from other technical routes after 2 doses of inactivated vaccines.
