January 21, 2022

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Chinese Adenovirus Vector Recombinant COVID-19 vaccine: Only one dose

Chinese Adenovirus Vector Recombinant COVID-19 vaccine: Only one dose

 

Chinese Adenovirus Vector Recombinant COVID-19 vaccine: Only one dose in the whole process, has been vaccinated in Shanghai, China.

On May 16, The Paper reporter learned from the Shanghai Centers for Disease Control and Prevention that since May 13, all districts of the city have begun to supply the vaccine. This vaccine was developed by CAnSinoBio and the team of Academician Chen Wei of the Institute of Bioengineering of the Academy of Military Medicine of the Chinese People’s Liberation Army Academy of Military Sciences. It will be the first to carry out clinical research in the world on March 16, 2020. On February 25 this year, this vaccine was approved by China State Drug Administration with conditions.

The Shanghai Municipal Center for Disease Control and Prevention revealed that compared with the three previously used inactivated vaccines for the new coronavirus in Shanghai, this adenovirus vector vaccine produced by CAnSinoBio is completely different in terms of technical principles and vaccination procedures, but in terms of vaccination methods and vaccination. The age range and safety are the same.

The first is that the technical principle is different. The adenovirus vector of this vaccine removes the replication-related genes in the adenovirus (human type 5 adenovirus, Ad5), so that the virus will not replicate in the human body. Then insert the new coronavirus spike protein (S protein) gene into it. This newly inserted gene allows the reassembled virus to enter the human body to replicate the new coronavirus spike protein in the body. Our immune system will initiate an immune response after discovering the spike protein and remember its appearance. The new coronaviruses will respond immediately to eliminate them.

This technology has previously been successfully used by Academician Chen Wei in the development of Ebola virus vaccines.

The familiar inactivated vaccine for the new coronavirus directly causes the new coronavirus to lose its infectivity and replication power through chemical methods, while retaining the active part that can cause the human immune response.

Secondly, the vaccination procedure is different. The basic immunization of adenovirus vector vaccine is 1 dose (0.5ml); the current recommended basic immunization procedure for the new coronavirus inactivated vaccine is 2 doses (0.5ml each), and the recommended interval of vaccination is 3-8 weeks. . Data from the Phase III clinical trial of the adenovirus vector vaccine showed that 28 days after a single injection of the vaccine, the total protective efficacy of the vaccine against all symptoms was 65.28%, and the protective efficacy against severe illness was 90.07%. Judging from the results of the neutralizing antibody crossover experiment conducted so far, the vaccine has a protective effect on the mutant strain.

However, the Shanghai Municipal Center for Disease Control and Prevention revealed that this vaccine is the same as the previous three inactivated vaccines in terms of vaccination method, vaccination age range, and safety. All vaccinators are injected into the deltoid muscle of the upper arm and are applicable to people aged 18 and above. .

At the same time, whether it is from the results of clinical trial research, emergency use research results, and post-marketing surveillance results, the COVID-19 vaccines that have been conditionally approved for marketing, including adenovirus vector vaccines and inactivated vaccines, are all Has good security. Adverse reactions after vaccination are the same as other vaccines. They are mainly redness, swelling, induration, pain, etc., as well as fever, fatigue, nausea, headache, and muscle aches. Generally, no special treatment is needed. If necessary, contact the vaccination site and the latter will give disposal instructions.

Experts from the Shanghai Center for Disease Control and Prevention said that the contraindications for this vaccine are similar to the three previous inactivated vaccines used in Shanghai, but it is important to remind people who are infected with HIV, scleroderma, dermatomyositis, and lupus erythematosus. Vaccination is not recommended for patients with immune system diseases at this stage.

At the same time, diabetic patients and those with a history of convulsions, epilepsy, encephalopathy or mental illness or family history should be used with caution; those with a history of asthma should be used with caution; patients with thrombocytopenia and any coagulopathy, intramuscular injection of this product may cause bleeding. Use with caution.

 

How long can the protective effect of adenovirus vector vaccine be maintained?

The Shanghai Municipal Center for Disease Control and Prevention revealed that the effectiveness data collected so far proves that the protection time of CAnSinoBio adenovirus vector vaccine can reach at least 6 months. Because the vaccine development time is not long, the vaccine immunity is persistent. Ongoing observation is still in progress. Previously, the immune durability observation of the Ebola vaccine using the same adenovirus vector technology showed that it still has sufficient protection after two years of vaccination.

Shanghai’s disease control experts suggest that for those who have received one dose of inactivated vaccine, it is recommended to use inactivated vaccine to complete the entire vaccination; for those who have already received two doses of inactivated vaccine, it is not recommended to use adenovirus vaccine for boosting.

In addition, experts also suggested that this vaccine is currently not recommended for simultaneous vaccination with other vaccines. The interval between other vaccines and the new coronavirus vaccine should be greater than 14 days.

When rabies vaccine, tetanus vaccine, and immunoglobulin are required due to animal injuries, trauma, etc., the interval between vaccination with the new coronavirus vaccine may not be considered.

 

(source:internet, reference only)


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