The COVID-19 epidemic is the most serious infectious disease pandemic that has occurred in the world in a century. It is also a major public health emergency that my country has encountered with the fastest spread, the widest range of infection, and the most difficult prevention

The COVID-19 epidemic is the most serious infectious disease pandemic that has occurred in the world in a century. It is also a major public health emergency that my country has encountered with the fastest spread, the widest range of infection, and the most difficult prevention and control. The Nanjing epidemic some time ago brought the Delta mutant strain into the public eye, and now a new mutant strain "Mu" has appeared. In the face of the ever-changing virus, the topic of booster shots of the new coronavirus vaccine has been mentioned repeatedly. The following will bring you detailed booster vaccination strategies.

What is the booster shot of the COVID-19 vaccine? Is it useful? Do you need to fight? Who gets priority for vaccination? When can I fight?

The so-called booster shot: Dr. Zhang Yujiao said that the booster shot refers to supplementary vaccination after completion of vaccination according to the disappearance of antibodies to maintain the body's immunity to the virus.

Why do we need booster shots?

This is because the protective effect of some vaccines may weaken over time. In order to provide additional protection, vaccination needs to be done again to stimulate the body's immune system and increase antibody levels.

establish herd immunity ?

Zhong Nanshan said that this is related to the effectiveness of the vaccine and also depends on the transmission coefficient of the virus. "The effectiveness of China's vaccine is about 70%, so China needs more than 80% of the entire population to be vaccinated to establish an effective herd immunity. Now, China's vaccination rate will probably reach more than 80% by the end of this year. "Academician Zhong Nanshan also said that if a booster shot is given 6 months after vaccination, the antibody level will increase by more than 10 times.

Is it safe after vaccination with a booster shot?

After the third dose of vaccination, the recipient's antibody level increased rapidly. It began to rise after 3 days, and rose to a higher level after 7 days. By 14 days, it was approximately equivalent to the original 15 -Varies from 30 times.

Who needs to fight?

expert analysis believes that the current epidemic prevention and control situation in our country is very good, with the focus being on preventing foreign imports. For those with high risk of importation, such as staff at customs, border inspection, aviation, isolation points, designated medical institutions, etc., after completing the immunization program for 6 days After 6 months, booster vaccination can be carried out; in addition, some people with low immune function and people over 60 years old can be carried out booster vaccination.

Are there any different opinions about "booster shots"?

Previously, the UAE national press conference announced the policy of booster shots of the new crown vaccine.

Image source: UAE National Press Conference

UAE residents will be able to receive booster vaccines six months after receiving the second dose, said Dr. Noura Al Ghaithi, Acting Chief Executive Officer of External Treatment Services at Abu Dhabi Health Services (SEHA), The elderly and those with chronic diseases will be prioritized for booster shots. She confirmed that getting a booster shot will further improve immunity and produce antibodies that can help fight off the virus.

As the number of people who have completed two doses of vaccination increases, the British government has also begun to consider implementing a third dose booster plan as soon as possible. According to previous news released by the British Ministry of Health, the government's independent expert group "Joint Committee on Vaccination and Immunization" recommended that the third dose of booster shots be started in September for the most vulnerable groups in the epidemic in order to strengthen the treatment of these groups before this winter. Protect.

Oxford University researchers used AstraZeneca vaccine as their research object and found that receiving the third dose of the vaccine can greatly enhance the immune response. But they also said there is currently no indication that a third booster dose is needed and stressed that the "top priority" is to ensure that people around the world receive the first dose of the vaccine.

Fosun’s mRNA vaccine is expected to become a domestic “booster shot”?

As the delta strain of the new coronavirus is raging around the world, most parts of the world are still shrouded in the shadow of the epidemic. To deal with the mutated strains, vaccines are still the main means of protection. In addition to the inactivated vaccine , which is currently an advanced and Fosun's mRNA vaccine (BNT162b2, Fubitai), which is effective against the new coronavirus, has been used for vaccination.

The new coronavirus Delta (Delta) variant strain was first discovered in India in October last year. It is more contagious than the original strain. According to data released by Public Health England, two doses of the BNT162b2 vaccine are effective in preventing Delta was 88% effective in symptomatic infection and 95% effective in preventing hospitalization.

In addition, on May 5, the results of a study on COVID-19 cases in Qatar published in NEJM ("New England Journal of Medicine") showed that the BNT162b2 vaccine is effective against the British variant (B.1.1.7) and the South African variant. The strains (B.1.351) all have high protective efficacy. Thirteen days after the second dose, the BNT162b2 vaccine was 89.5% protective against infection with the B.1.1.7 mutant strain and 75% protective against B.1.351. The protective efficacy against severe disease, critical illness and death caused by the two mutant strains was 97.4%.

BNT162b2 vaccine protective efficacy against B.1.1.7 and B.1.351 mutant strains

Image source: NEJM Paper screenshot

According to Israeli vaccination data [1], the third dose of BNT162b2 vaccination campaign was launched in August 2021, aiming to In assessing the initial short-term effectiveness of three-dose versus two-dose regimens against SARS-CoV-2 Delta variant infection, two complementary approaches were used; a test-negative design and a matched case-control design.

During the trial period, a total of 153,753 MHS members participated, with 149 379 tests conducted in the two-dose group and 8 285 positive results (5.5%), and 32 697 total tests conducted in the three-dose group with 1 188 positive results ( 3.6%). The odds of testing positive for SARS-CoV-2 infection were reduced by 48-68% 7-13 days after a booster shot, and marginal effectiveness increased to 70-84% 14-20 days after a booster shot.

Fosun's mRNA vaccine is different from traditional inactivated vaccines and attenuated vaccines. It is a masterpiece of the most cutting-edge biomedical technology. The mRNA vaccine is a nucleic acid vaccine and has an overwhelming advantage over other vaccines.

This vaccine can effectively deal with more than 20 mutated viruses, and has high protective efficacy for the elderly and people with various chronic diseases. Fosun's mRNA vaccine (BNT162b2, Fubitai) can provide double immunity and protection after large-scale population vaccination Efficacy is as high as 95%.

Currently, the BNT162b2 vaccine has been authorized for use by health regulatory authorities in more than 70 countries and regions, including the United Kingdom, the United States, Canada, Israel, the European Union , and more.

On September 2, 2021, Shanghai Fosun Pharma (Group) Co., Ltd. ("Fosun Pharma" or the "Group", stock code: 600196.SH, 02196.HK) announced that on September 2, Fosun Pharma The first batch of the mRNA COVID-19 vaccine BNT162b2 produced by BioNTech and supplied to Taiwan arrived at Taoyuan Airport in Taiwan from Europe, with the first batch of 932,000 doses arriving. This vaccine will be donated to Taiwanese compatriots through donations from private institutions in Taiwan. It is suitable for active immunization of adolescents and adults over 12 years old to prevent diseases caused by new coronavirus infection.

In this way, in response to the situation where mutant strains of the new coronavirus have repeatedly "broken defenses", causing ordinary vaccines to be ineffective or even triggering the ADE (antibody-dependent enhancemen) effect, the mRNA vaccine has become a more reliable vaccination option. A person familiar with the matter said that Fosun’s mRNA vaccine is expected to become a “booster shot” in China.

Regarding the mRNA vaccine, you want to ask...

Why should people aged ≥65 years be vaccinated?

As age increases, the immune function of the elderly declines or the immune response weakens. The body is unable to produce sufficient antibodies in time, and the risk of infection with the new coronavirus increases. At the same time, the elderly often suffer from multiple comorbidities, and infection with COVID-19 will cause more serious health problems.

Fosun’s mRNA vaccine was successfully developed in such a short period of time. Is it safe to vaccinate?

Dr. Hui Aimin, Global R&D President and Chief Medical Officer of Fosun Pharma, said that mRNA technology is a technology with very broad application prospects. The smallest living unit of human life is protein. If something goes wrong with the protein, various diseases may occur. It can be at the DNA level, or it can be at the RNA level, or the protein itself.The mRNA technology means that no matter where problems occur, it can give you an mRNA that the human body can produce normal and good proteins.

On March 16, 2020, Fosun Pharma and BioNTech announced a strategic cooperation agreement. The two parties will jointly develop and commercialize novel coronavirus based on their proprietary mRNA technology platform in mainland China, Hong Kong, Macao and Taiwan. vaccine products.

In July 2021, Fosun Industrial (Hong Kong) Co., Ltd., a holding subsidiary of Fosun Pharmaceuticals, signed contracts with companies including TSMC , Hon Hai , Yongling Foundation, Tzu Chi Foundation and Zuellig Pharma for a total of 15 million doses. Sales agreement for the mRNA COVID-19 vaccine BNT162b2.

Currently, the preventive biological product BNT162b2 (Fosun mRNA vaccine) has been approved by the U.S. Food and Drug Administration (FDA) for emergency use in people aged 16 and above. It is available in many countries including the United States, the United Kingdom, and the European Union. and regional emergency use authorizations, approved for vaccination worldwide.

Image source: U.S. Food and Drug Administration (FDA) official website

In addition to domestic trials, according to the results of the global Phase III clinical trial previously announced by Pfizer, BioNTech’s mRNA COVID-19 vaccine has reached all major efficacy endpoints. It is 95% effective in preventing new coronavirus infection, more than 94% effective in adults over 65 years old, and shows consistent effectiveness across age, gender, racial and ethnic groups.

Fosun Pharma Chairman and CEO Wu Yifang said, "We are very happy to see that this mRNA COVID-19 vaccine, jointly developed by Fosun Pharma and BioNTech, can play a positive role in the prevention and control of the epidemic among Taiwan compatriots. , to help Taiwanese compatriots build an immune barrier against the new crown virus. "

The public can be very confident that this vaccine meets high standards of safety, effectiveness and manufacturing quality. When used, it takes two shots of "basic and booster" (vaccinated 21 days apart). Immunization program.

Under what circumstances will one be infected with the new coronavirus after receiving the Fosun mRNA vaccine?

According to the results of Phase III clinical trials, the final effectiveness of the vaccine can reach 95%, which means that this vaccine can effectively reduce the chance of infection.

How long does it take for the Fosun mRNA vaccine to take effect after vaccination? How effective is it?

clinical trial results show that the mRNA vaccine has a vaccine effectiveness of 52% during the 21-day interval between two doses, 91% effectiveness within 7 days after the second dose of vaccine, and 95% effectiveness 7 days later.

If the virus mutates, will Fosun’s mRNA vaccine still be useful?

According to July 22, 2021, the "New England Journal of Medicine" [2] (NEJM) published a research paper online on the protective efficacy of vaccines against delta variant strains. The results showed that the mRNA vaccine BNT162b2 and the adenovirus vector vaccine ChAdOx1 nCoV-19 It can effectively prevent symptomatic infections caused by the Delta variant first discovered in India (also known as B.1.617.2). The protective efficacy of two doses of BNT162b2 vaccine against the Delta variant is 88.0%.

Picture from Effectiveness of Covid-19 Vaccines against the B.1.617.2 (Delta) Variant

In other words, after being vaccinated, for yourself, if you are infected with the virus, the antibodies induced by the vaccine can reduce the risk of disease. 88%. For groups, vaccinated people can reduce the incidence rate by 88% compared with unvaccinated people.

Now that there are very few confirmed cases in mainland China, is it still necessary to vaccinate with the Fosun mRNA vaccine?

Before we can completely defeat the new coronavirus, it is necessary to get vaccinated against the new coronavirus. If we want to end the COVID-19 epidemic, it is estimated that 60%-70% of the population will need to be vaccinated to gain immunity. Therefore, vaccination is urgent and necessary.

So far, more than 2.1 billion doses of COVID-19 vaccines have been administered nationwide, mainly inactivated vaccines, which have been widely used and have proven safety and immunogenicity. As a new generation of nucleic acid vaccines, mRNA vaccines have the advantage of relatively strong cellular immune response, which can complement well with inactivated vaccines that mainly induce humoral immunity and . The powerful combination of mRNA vaccines and inactivated vaccines will provide people with new weapons to deal with various mutant strains.

Reference:

[1]Short Term Reduction in the Odds of Testing Positive for SARS-CoV-2; a Comparison Between Two Doses and Three doses of the BNT162b2 Vaccine

doi: https://doi.org/10.1101/2021.08.29.21262792

[2]Bernal JL, et al. N Engl J Med. 2021 Jul 21. doi: 10.1056/NEJMoa2108891.

https://www.nejm.org/doi/full/10.1056/NEJMoa2108891