The Development of COVID-19 Vaccines

The World in COVID-19

A COVID-19 vaccine could not come soon enough. However, it will be some time before we see this come to fruition.

The spread of COVID-19 has caused unprecedented disruptions around the world. Many peoples lives have been severely impacted and many nations are facing unprecedented levels economic hardship. The impacts of this pandemic are being felt far and wide. Even when this virus is under control, the time frame for recovery will be a long one.

As we pass the half-year mark of combating COVID-19, there several nations that have appeared to have the virus under control. Case numbers in these regions are either not increasing or growing at a significantly reduced rate. These countries have begun lifting restrictions and allowing their citizens to return to a state of pseudo-normalcy. Many are calling this a “new normal”. In these places, social-distancing is in place, many are still working from home, and most hospitality-related businesses are running at reduced capacity.

covid-19 vaccine development

As the restriction lifting continues, there is mounting fear of a viral 2nd-wave. Efforts are being made to lessen the chance of this happening. One such strategy is the extensive testing of the population. This can be done with COVID-19 Antigen Rapid Tests and COVID-19 IgM/IgG Rapid Tests. These test for the presence of viral antigens or viral antibodies. These antibodies would be produced by people either currently fighting or have recovered from a viral infection. However, the only true solution that we have for this pandemic, is the development of a COVID-19 vaccine. To discuss vaccines, we should first discuss how the body fights back against infection-causing pathogens.

How does your body fight diseases like COVID-19?

The beginning of this whole process is when a pathogen enters your body and is identified by your immune system. At this point, your body will being producing proteins called antibodies that will fight back against the intruder. With these antibodies, your immune system is now equipped to effectively fight against this specific pathogen.

Antibody production usually begins a few days into an infection. This is the point when you are visibly sick and experiencing symptoms of the illness caused by that pathogen. For some diseases, your body can very effectively produce antibodies and thus fight the infection. This can be an issue for stronger pathogens, as there is the chance that you will die before enough antibodies have been produced. For these stronger pathogens such as the one we are currently dealing with, a COVID-19 vaccine would come in.

What do vaccines do?

If your immune system fighting the pathogen is akin to going into a battle or a fight, a vaccine can be considered immune system training or target practice. There are a few types of vaccines, which we will briefly discuss here, but the basic premise for all of them is that the vaccine allows your body to simulate a real infection. This is done by exposing your body to the pathogen so that your body’s immune system is activated into producing the appropriate antibodies. This exposure can be done by using a significantly weakened or killed version of the pathogen, or only specific parts of the pathogen (like a protein, sugar, or cell portion). Thus, if the vaccine does its job, your body will be well and ready to fight the real pathogen if it encounters it in the wild.

Types of vaccines that you could be used to fight COVId-19

There are a few different vaccine types available, with several respective advantages and disadvantages.

Attenuated Vaccines:

These vaccines are made up of attenuated (weakened) but still viable (alive) pathogenic particles. As such, the immune response is much stronger. This means that all aspects of the body’s immune system are activated, meaning that booster shots are typically not required. If you need a strong vaccine, attenuated is the way to go. Issues related to this include potential complications arising if in the very rare case that the weakened virus mutates back to a virulent strain, and potential health risks in those who are immunocompromised. An additional issue would be the more stringent storage conditions to keep the pathogen alive; this can include the necessity for fresh media or storage solution, as well as the requirement for refrigeration. This can be an issue when extended transportation and storage is required, especially to remote locations. Examples of attenuated vaccines include those used for measles, smallpox, chickenpox, and yellow fever.

Inactivated Vaccines:

These vaccines are made up of previously viable (living) pathogens that have been inactivated (killed), with this being done by heat or chemical means. The benefit of this vaccine type is that, in comparison to an attenuated vaccine, a living pathogen is not introduced into the body, and storage conditions are much less rigorous allowing for easier transport. One disadvantage is that these vaccines typically do not produce as strong of an immune response as a vaccine containing a weakened form of the virus, thus booster shots are usually required. Examples of inactivated vaccines include those used for Hepatitis A, seasonal Influenza, and Polio.

Conjugate, subunit, recombinant, and polysaccharide vaccines:

These types of vaccines depend on the use of only a part of the pathogen, not the whole pathogen, to generate an immune response. These parts could include glycans and sugars that would be expressed on the outside of the pathogen, pathogenic surface proteins, or parts of the capsid (outer coating) of the pathogen. The type of piece that is used will depend on the pathogen and how the body’s immune system responds to these pathogens. Benefits of these include a very strong immune response, as only the component of the pathogen that generates a response is added, and these vaccine types do not cause additional complications in those with other health issues or compromised immune systems. Disadvantages include the potential requirement of booster shots to keep up immunity over time. Examples of pathogens that utilize this type of vaccine include Hepatitis B, HPV (Human Papillomavirus), and shingles.