COVID-19 vaccines: development and monitoring
It is increasingly recognized that more SARS-CoV-2 vaccines will be introduced soon and in this sense it is also important to have into consideration that all the available vaccines will need to be monitored in extensive populations. There are a wide range of potential vaccines for COVID-19 in study process at the moment.
However, if any of these vaccines prove to be safe and effective soon, they will need to be approved by national regulators, manufactured following strict standards and then, they will be able to be distributed. There have been global efforts to manufacture effective diagnostic technologies which are the key for the monitoring of COVID-19, specifically, serological testing will be vital in monitoring antibody levels, and the immune response to the different vaccines.
▌ Is there a COVID-19 Vaccine?
Yes. There are three COVID-19 vaccines for which certain national regulatory authorities have authorized the use. Large studies of 5 vaccine candidates efficacy and safety results have been publicly reported through press releases. We expect more such reports in the near future. The types of vaccines that have been investigated so far act in different ways, these are the main ones:
- mRNA Vaccines: They contains material from the SARS-Cov-2 virus and this material will give instructions to our cells about how to make a harmless protein that is unique for the virus. Our body will recognize that the protein should not be there and build T-lymphocytes and B-Lymphocytes that will remember how to fight the virus.
- Inactivated or weakened virus vaccines: They use a dorm of the virus that has been inactivated or weakened so it doesn’t cause disease, so our body will react and will generate a an immune response to fight to the virus.
- Viral Vector Vaccines: these vaccines use a virus which has been genetically engineered in order to prevent it to cause the disease, and its work will be make our system to generate an immune response.
- Protein-based vaccines: They use harmless pieces of proteins or protein shells that copy the SARS-CoV-2 virus, in response to that our immune system will recognize that the proteins don’t belong in the body and will make T-lymphocytes and antibodies to fight against the virus in future infections.
You can follow the progression of the vaccines on this link on WHO’s website.
▌ Is COVID-19 vaccine safe?
As we have seen before in this article, any licensed vaccine is rigorously tested across multiple phases of trials before it is approved for use, and regularly revaluated once it is introduced. Scientists are also constantly monitoring information from several resources for any sign that a vaccine may cause risks. This means this vaccine is not more dangerous than others that have been approved before. The fast development of this vaccine is due to the inversion in investigation and development has been larger than usual, companies have invested in order to go through all the process faster than usual.
Additionally, there have been so many companies and people working simultaneously in order to make this process faster, investigators and scientists have been working non-stop in this vaccine and they keep on working on it worldwide. These vaccines have not been created out of nothing, they are all based on other studies and previously studied technologies for another similar virus and infections, and they have been adapted to the specific characteristics of SARS-CoV-2. Furthermore, to ensure safer vaccines, as we have explained before, these laboratories have followed the whole process established and they will have to be authorized to be commercialized.
▌ How are vaccines tested?
According to WHO’s website, this is the procedure vaccines must follow to be safe:
- Phase I: the vaccine is given to a small number of volunteers to assess its safety confirm it generates an immune response and determine the right dosage.
- Phase II: The vaccines is usually given hundreds of volunteers, who are closely monitored for any side effects, to further assess its ability to generate and immune response. Participants in this phase have the same characteristics (such as age and sex) as the people for whom the vaccine is intended. In this phase, some volunteers receive the vaccine and others do not, which allows comparisons to be made and conclusions drawn about the vaccine.
- In phase III, the vaccine is given to thousands of volunteers – some of whom receive the investigational vaccine, and some of whom do not, just like in phase II trials. Data from both groups is carefully compared to see if the vaccine is safe and effective against the disease it is designed to protect against.
▌ Do I need to be vaccinated if I have already passed the COVID-19?
There is no information about long-term protection of COVID-19 vaccines yet. There will be additional research in order to answer this question, however, available data suggest that most people who recover from COVID-19 develop an immune response that provides some protection against reinfection, although there are still trying to discover how long it will last. For this reason, it is not clear how many doses of a Covid-19 vaccine will be needed, even though the most vaccines being tested at the moment are using two doses.
In this sense, and looking at emerging data, patients are susceptible to second infections of COVID-19 after losing immunity, and due to the severe health risks associated with COVID-19 people may be advised to get the vaccine even if they have been exposed to the virus before. However, serology testing which allow to quantify antibody levels, will be critical in monitoring these patterns.
▌ Why is Serology testing the key to monitor SARS-CoV-2 Vaccine performance?
COVID-19pandemic has shown the important need for molecular diagnostics, and we can analyze how countries that have developed early their testing resources and capability have managed the outbreak more successfully.
In this sense, serological surveys are essential for the next stage of the pandemic we are going to face. Throughout serological surveys we are able to look for antibodies against the SARS-CoV-2 virus in population groups, and the main objectives of these surveys is, firstly to learn how many people of that group have been exposed to the virus, and secondly, which of those groups are more exposed or have had higher rates of infections. Additionally, the public health authorities will have an idea of how infection rates are progressing in a particular area. These tendencies will give us so much information about how the human immune system works against the SARS-CoV-2 virus, how long antibodies last and how long they protect us. These tests also give an opportunity to answer all those questions.
▌ SARS-CoV-2 Serology hihly realiable Tests
On June 2020 Immunostep announced the development of a quantitative antibody test to detect SARS-CoV-2 antibodies in human serum and plasma, these serological tests are now available and will help supporting the evaluation of vaccines in this new phase of the pandemic that we are going to face soon. This new serological test has the main advantage that it can detect antibodies from the onset of symptoms, allowing to confirm patients with recent and past infection, which opens opportunities for a better understanding of the immune response and its evolution over time after vaccination.
This test has been developed to quantify the antibodies that specifically bind to the Cysteine-like Protease protein of the virus, a key in viral replication during the infection process. In this sense, Immunostep is committed to provide reliable and accurate testing products to investigate population immunity.