Now there are many studies of SARS-CoV-2 vaccines in animals and human. One of the concerns relating to safety of vaccine is the immune-enhanced disease. But I wonder which animal experiments could clearly show this concern.
In a recently published paper of Qiang Gao et al (DOI: 10.1126/science.abc1932), they vaccinated three times and then autospied the macaques, estimated the lung inflammation levels without challenge. How do you think of this experiment?
Dear Mr. Nguyen!
Yours question is an essential one! It is vital to know how long immunity exist in animals and humans against this deadly virus. A researcher of microbiology was interviewed some days ago and he stated some new facts I was not aware that time: this virus mutates approximately every second week. In so they could not track it down in Italy after type 1 from China arrived in Europe. There has been many cases where people without symptoms become host to the virus spreading out the disease further out. Even more worrying was the new from Asia when day found a woman who got sick the second time with corona within a moth after recovering from it before. These cases indicate that immunity does not lasts long. The agile mutation capability of this virus is a problem when setting up experiments:
Ana María Rodríguez, Ph.D, Peter J. Hotez, David B. Corry, Maria Elena Bottazzi. (2020). "The challenges of developing a safe and effective COVID-19 vaccine" 12 May 2020, Baylor College of Medicine, Citation: " How to design a vaccine that safely protects against COVID-19..."
Available at:
Article COVID-19 vaccine design: the Janus face of immune enhancement
In the UK, there is a trial-phase going on to test a vaccine on humans:
University of Oxford (2020). "COVID-19 drugs trial rolled out across UK homes and communities" 12 May 2020, © University of Oxford 2020, Available at:
http://www.ox.ac.uk/news/2020-05-12-covid-19-drugs-trial-rolled-out-across-uk-homes-and-communities
Yours sincerely, Bulcsu Szekely
Hello Dr CONG: My input concerning your question:
Importantly, SARS-CoV-2 vaccines will be essential to reducing morbidity and ... (SARS) coronavirus from 2003, earning the new virus the name SARS-CoV-2 . Initial work showed that it can use angiotensin-converting enzyme 2 (ACE2) ... whereas immunity to others seemed to be enhancing disease.
Article SARS-CoV-2 Vaccines: Status Report
https://www.nature.com/articles/d41586-020-00798-8
Article Projecting the transmission dynamics of SARS-CoV-2 through t...
Regards--
Hi
Please check the following link. I believe it will help you.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7161485/
Regards
In December 2019, the outbreak of pneumonia caused by a novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has led to a serious pandemic in China and other countries worldwide. So far, more than 460,000 confirmed cases were diagnosed in nearly 190 countries, causing globally over 20,000 deaths. Currently, the epidemic is still spreading and there is no effective means to prevent the infection. Vaccines are proved to be the most effective and economical means to prevent and control infectious diseases. Several countries, companies, and institutions announced their programs and progress on vaccine development against the virus. While most of the vaccines are under design and preparation, there are some that have entered efficacy evaluation in animals and initial clinical trials.
How to know that a vaccine against SARS-CoV-19 (causing COVID-19) has induced immunity and is effective?
The experimental study on Rhesus macaques (monkeys) clearly showed that the monkey that had developed antibodies, on re-exposure to SARS-CoV-2 did not develop the disease. However, the duration of immunity could not be judged because none of the animals were left alive to check the long-term immunity (1).
It would not be ethical to do a similar study in humans.
Only way is to check the SARS-CoV-2 specific antibodies in COVID-19 recovered patients, check the antibodies quantitatively over every 3-6 months and then check how long the titre of the antibodies last (just like it is done after Hepatitis B vaccination).
If a vaccine is side-effect free and produces antibodies against SARS-Cov-2 in humans at different doses in human volunteers, then the antibody tiers can be followed up at different times every 3 monthly not having had COVID-19, to know the effective dose as well as the need for booster dose of the vaccine.
The duration of immunity after SARS (caused by SARS-CoV-1) was between 1-3 years (2). If we extrapolate those results to SATS-CoV-2 causing COVID-19, immunity may be at least 6-12 months.
Only issue is that the viral vaccines are strain-specific (for example Influenza vaccines need to be prepared every year incorporating the influenza starins of last year), and unless the vaccine is not developed by against all the strains causing COVID-2, its passive immunity caused by such vaccine may not be effective at a global level.
1. Preprint Reinfection could not occur in SARS-CoV-2 infected rhesus macaques
2. Article Duration of Antibody Responses after Severe Acute Respiratory Syndrome
Sorrento Therapeutics Says Antibody Shows Ability To Block Virus
Sorrento soars on positive news from COVID-19 antibody program
Hi everyone,
Thank you so much for giving me the answers. I am appreciative of your help so much.
Dear Mr. Nguyen!
Yours question is an essential one! It is vital to know how long immunity exist in animals and humans against this deadly virus. A researcher of microbiology was interviewed some days ago and he stated some new facts I was not aware that time: this virus mutates approximately every second week. In so they could not track it down in Italy after type 1 from China arrived in Europe. There has been many cases where people without symptoms become host to the virus spreading out the disease further out. Even more worrying was the new from Asia when day found a woman who got sick the second time with corona within a moth after recovering from it before. These cases indicate that immunity does not lasts long. The agile mutation capability of this virus is a problem when setting up experiments:
Ana María Rodríguez, Ph.D, Peter J. Hotez, David B. Corry, Maria Elena Bottazzi. (2020). "The challenges of developing a safe and effective COVID-19 vaccine" 12 May 2020, Baylor College of Medicine, Citation: " How to design a vaccine that safely protects against COVID-19..."
Available at:
Article COVID-19 vaccine design: the Janus face of immune enhancement
In the UK, there is a trial-phase going on to test a vaccine on humans:
University of Oxford (2020). "COVID-19 drugs trial rolled out across UK homes and communities" 12 May 2020, © University of Oxford 2020, Available at:
http://www.ox.ac.uk/news/2020-05-12-covid-19-drugs-trial-rolled-out-across-uk-homes-and-communities
Yours sincerely, Bulcsu Szekely
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