For most people in the last 12 months, school became an entity of ZOOM, masks became as necessary as shoes, and leaving the house became a momentous occasion. While we were adjusting to our new normal, scientists and doctors worked tirelessly to produce a vaccine and host clinical trials with minimal available data and time. Keep in mind that vaccines usually take years or even decades to develop, and while funding from governments surely expedited the development process, it is impressive that the world was able to work together to produce vaccines in such a short time frame without sacrificing safety or efficacy.
In the USA, the FDA has given emergency approval (called a EUA, full approval can only be granted after more data is collected) to Moderna and Pfizer-BioNTech to distribute their vaccines. AstraZeneca is expected to be one of the next approved vaccines, but currently it is not as effective as the other two and requires more testing. Both Moderna and Pfizer are messenger RNA (mRNA) vaccines. mRNA is a piece of genetic material created in a lab which contains instructions for your cells on how to make a specific protein. To be more specific:
1. The mRNA enters your cells after being injected into the upper arm muscle.
2. Once inside the cells, the mRNA distributes instructions that teach the cells how to make a certain “spike” protein. This spike protein is also found on the surface of the virus that causes COVID-19.
3. After making the spike protein piece and displaying it on its surface, the cell can break down the mRNA instructions and discard them.
4. When the immune system ‘sees’ the spike protein on the cell's surface, it will recognize that it is a foreign compound that does not belong there. This triggers an immune response (which is why people experience side effects after getting the vaccine) that creates the antibodies* to destroy that type of spike protein.
5. Because the antibodies needed to fight off COVID-19 are now present in your body, you would be protected from getting seriously ill if you were to get exposed to the real virus.
*An antibody, in simple terms, is a type of blood protein that is developed by the immune system in response to a foreign substance. People who have already been infected with COVID-19 may have some leftover antibodies to protect them somewhat from future infections, but they are still recommended to get the vaccine.
To clarify, this means that the Moderna and Pfizer vaccines do not contain a live sample of the virus that causes COVID-19 so you cannot get COVID-19 directly from the vaccine. It also does not alter your DNA, because the mRNA does not enter the cell’s nucleus where DNA is kept. There is also no evidence, as of now, to suggest that those with the vaccine cannot spread the virus to others as asymptomatic carriers (meaning that even vaccinated people should continue wearing masks and social distancing to protect others). Additionally, the vaccine does not grant the patient infinite immunity, though it is too early to tell for sure, experts speculate that the immunity will last for a few years after getting the vaccine (perhaps the COVID-19 vaccine will become something administered annually, like the flu shot). Even if everyone can get vaccinated, COVID-19 will never be totally eradicated, so it is important we continue doing our part wearing masks and socially distancing.
From a basic scientific perspective, the Moderna and Pfizer vaccines work very similarly, but there is a few key differences listed in the comparison below:
In light of the abruptness of the coronavirus and development of vaccines, many people are (understandably) hesitant and afraid of vaccination. However, we must remember that the clinical trials show that it is very rare for recipients to experience severe adverse side effects. The FDA, after weighing the risks and benefits, would not have approved the vaccine for emergency use if it was unsafe for the majority of the people. The CDC even recommends immunocompromised people (those with immunocompromising conditions like HIV or those using immunosuppressant treatments like chemotherapy) and those with autoimmune diseases still get the vaccine if they do not have other reasons to avoid vaccination. However, those allergic to polyethylene glycol (or other vaccine ingredients) and polysorbate or with a history of severe allergic reactions to other substances should check with their doctors and may want to avoid getting the vaccine until more data is available. The CDC's website contains more information on who is safe to get the current vaccine.
One more group that is currently unable to get the vaccine (unless they are participating in a clinical trial) are children and adolescents under 16. Testing the vaccine in children has taken longer because clinical trials are drawn out to ensure maximum safety of the participants. Also, most of the children who are exposed to COVID-19 survive, so the companies did not think it was worth the risk to start doing clinical trials until the effects on adults were better understood. Since children need to get vaccinated in order for school to begin to look normal again, Moderna, Pfizer-BioNTech, Johnson & Johnson and AstraZeneca have begun (or began planning) clinical trials in older children (usually 12-15) and then will be able to begin testing younger children and babies. These processes must be taken slowly because adults, teens, children and babies all have very different immune systems and immune responses.
While there is a lot of uncertainty, we know that the more people that get vaccinated, the better. As of January 28, about 21.2 million people have been given at least one dose of a COVID-19 vaccine, and 4.3 million have been fully vaccinated (for updated statistics visit the CDC here). Most of these people are nursing home residents or front-line medical workers. The federal government has distributed nearly 50 million doses of the vaccines and sent them to states, territories and federal agencies roughly proportional to their populations. However, distributing vaccines is time consuming and poses serious logistical challenges (especially because the vaccines must be stored at ultra-low temperatures and vaccination centers must ensure patients return for their second dose). For instance, on January 28, 2021 (view updated percentages here) only 5.8% of the population in California had received at least one dose of the vaccine, meaning 50% of the provided doses have been used.
But, despite the scary numbers and uncertainty, I want to leave you with a positive thought from Brigham C. Willis, senior associate dean for medical education and professor of pediatrics at UC Riverside’s School of Medicine. He said, “The rapidity with which we developed a vaccine for a deadly, pandemic-causing virus should be celebrated, and we should be so excited... The fact that it works so well could be of incredible import for many diseases. Even though it’s been a dark time, this was an incredible advance for medicine — and could be a really important advance for mankind.”
Sources:
https://www.webmd.com/vaccines/covid-19-vaccine/news/20201214/closer-look-at-three-covid-19-vaccines
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