By MADELYN BOGLIOLI and CAROLINE CASIERI 3/1/2021
Almost a year into the pandemic, the new COVID-19 vaccines are providing a light at the end of a very, very long tunnel. While many are excited about the vaccine, most don’t know how the vaccines actually work. We at the Tiger Times hope that the following will answer any questions you may have about the vaccine.
What are mRNA vaccines?
As you may or may not know, the vaccines currently available in the United States (Pfizer and Moderna) are examples of mRNA vaccines. Messenger RNA or mRNA is genetic material that contains the instructions for making proteins. mRNA vaccines inject your body with the instructions for producing viral proteins. In layman's terms, it tricks your body into thinking it has COVID-19 by making fake copies of the virus. Your body then develops the antibodies to fight off the virus, so if you ever do come in contact with COVID-19, it won’t take hold in your body.
What are adenovirus vector vaccines?
While these types of COVID vaccines haven’t been administered or approved by the United States, adenovirus vaccines are also promising. These types of vaccines use the body of an adenovirus, and use it to carry COVID-19 spike proteins (instructions to produce antibodies for the coronavirus). The main difference between these vaccines and mRNA vaccines is that vector vaccines use the body of a virus to deliver the spike proteins whereas the mRNA vaccines inject your body with the spike proteins that then travel straight into your cells. The two are very similar concepts. The most well known adenovirus vector COVID vaccine is AstraZeneca which will be discussed later.
How do mRNA vaccines and traditional vaccines compare?
In traditional vaccines, such as the flu shot, weak or heat-killed viruses are injected into you. However, in mRNA vaccines, you aren’t coming into contact with the real virus, instead you are creating proteins similar to COVID-19. Both types of vaccines teach your body to fight off diseases by allowing your body to make antibodies to fight the virus. Traditional vaccines use viruses that are grown in labs using animal cells, whereas mRNA vaccines use viruses created in your body. This makes mRNA vaccines more effective than traditional vaccines. Additionally, mRNA is better in that it better simulates being actually infected with the virus, but is still just as safe as traditional vaccines. mRNA vaccines are faster and easier to produce than traditional vaccines because they don’t require the real virus. Research suggests that mRNA vaccines will be more effective than traditional vaccines, but because mRNA vaccines are so new there is no conclusive evidence.
Pfizer v.s. Moderna
The Pfizer and Moderna vaccines are both mRNA vaccines and are both very effective. Thus far, Pfizer has been shown to have a 95% effectiveness rate while Moderna is a close second at 94%. This is considered to be excellent, for reference the 2018 flu shot had a 47% effectiveness rate. Alo, both vaccines have very few and very similar side effects. The Moderna vaccine is only approved for people 18 and over, while Pfizer is approved for 16 and over. However, both vaccines are undergoing tests for people 12 and over. Both vaccines have to be frozen, but Pfizer has to be stored in special freezers that get to -94 degrees fahrenheit and Moderna can be stored at -4 degrees fahrenheit (a regular freezer temperature). [EDIT: news emerged that the Pfizer vaccine can also be stored at regular freezer temperatures] Additionally the time between the two doses of the vaccines are different. For the Pfizer vaccine a person only needs to wait 21 days to get the second dose, while for Moderna you need to wait over 28.
What are the temperature requirements for the vaccine?
Many of the vaccines, including Pfizer and Moderna, need to be stored at incredibly cold temperatures. This is because if mRNA vaccines are kept at room temperature for too long their contents will start to break down. RNA degrades almost immediately after it is read by your cells, and the vaccine needs to be kept at extremely low temperatures to prevent it from degrading before it enters your body.
The Pfizer vaccine needs to be kept -94 degrees fahrenheit, which is colder than Antarctica! Pfizer is currently the coldest stored COVID vaccine on the market.
What are the side effects?
The Pfizer and Moderna vaccines have been shown to have similar side effects and most people have reported experiencing them only after the second dose. The most common side effects have been muscle ache, fever, chills, joint pain, and nausea. In rare cases, severe and life-threatening reactions have occurred which is why the recipient is supposed to wait in the office for 15 minutes after the injection to make sure that they will be okay.
How are Pfizer, governments, and private companies working together to roll out the vaccine?
Pfizer gave governments around the world the opportunity to purchase a certain amount of doses as part of a contract based on if the vaccine was safe and effective. All countries interested were able to request a certain number of doses they could purchase if the vaccine was approved for emergency use by the FDA and other health organizations. Vaccine distribution is based on the different contracts countries signed determining the amount of vaccines they would purchase from Pfizer by a certain date. Additionally, Pfizer has given away millions of doses to developing countries who cannot afford the vaccine.
In order for the vaccines to be disseminated to its recipients, private companies are responsible for receiving doses from Pfizer manufacturing sites and delivering them to hospitals, pharmacies, and doctors offices so they can be administered.
What other vaccines are being developed and used for COVID-19?
So far the Pfizer and Moderna vaccines are the only ones approved for use in America, other vaccines are on the rise. Experts are predicting that the “Big 5” vaccines in America will eventually be the two mRNA vaccines - Pfizer and Moderna - the two vector vaccines - AstraZeneca and Johnson and Johnson - and the very different Novavax subunit vaccine.
AstraZeneca
The AstraZeneca vaccine has shown immense promise and confirms 100% protection against hospitalization, death and severe disease in the primary analysis of their phase 3 trials. AstraZeneca made headlines announcing that their vaccine only needed one dose. This is not completely true. AstraZeneca can technically be given in one dose, but the effectiveness is only around 70%. If a second dose is given that rate increases to over 80%. AstraZeneca is being sold to countries all over the world, but especially to developing countries. Developed countries “snatched” up all of the Pfizer and Moderna vaccines because they were slightly more effective and they were approved first. AstraZeneca is an example of an adenovirus vector vaccine.
Johnson and Johnson
The Johnson and Johnson vaccine has not been given as much press attention as the Moderna, Pfizer, and AstraZeneca but it is definitely up and coming. The Johnson & Johnson vaccine is another example of an adenovirus vector vaccine. The J&J vaccine is 66% effective at preventing moderate to severe COVID and drastically decreased hospitalization rates and death in their trials. Compared to the other vaccines that have been approved or are in the works, J&J is not as effective. However, J&J’s vaccine could still be a powerful weapon in the war against COVID-19. J&J submitted its application for approval to the FDA very recently and hopes to roll out soon in the United States. Another benefit to the J&J vaccine is that it can be stored at the same temperatures as the Moderna vaccine, but for much longer. It can stay in the freezer for up to two years and the fridge for up to 3 months.
Novavax
The Novavax vaccine works differently than the other vaccines out there. It is a subunit vaccine. University of East Anglia professor of medicine Paul Hunter describes that subunit vaccines “work by tricking the body’s cells to manufacture the parts of the virus that then trigger the immune system,” it “is made up with proteins from the virus already attached to a carrier and these trigger the immune system directly.” Subunit vaccines are easier and faster to produce than mRNA vaccines and Subunit vaccines are made in different factories, so their approval would not put extra strain on the factories trying to keep up with the growing demand for mRNA vaccines. The Novavax vaccine was 89.3% effective in the UK. Broken down - 95.6% for the dominant strain and 85.6% for the UK variation. Novavax is still recruiting participants in the US and Mexico for their Phase 3 trials, which could delay their approval by the FDA.
Sputnik V
The Sputnik V vaccine was developed in the Gamaleya National Centre of Epidemiology and Microbiology in Russia. The vaccine is currently registered for use in 20 countries, but is mainly used in Russia. The Sputnik V vaccine is an adenovirus vaccine and can be kept in a regular fridge. The vaccine is two doses three weeks apart and is proven to be 92% effective. Interestingly, there are some strange guidelines to follow after receiving the Sputnik V vaccine: recipients are instructed not to swim, drink alcohol, go to the gym, or go to a sauna for three days following each dose. Although the vaccine has proven to be very effective and safe, many Russians are resisting getting vaccinated for political reasons. Vladimir Putin released the vaccine before it was fully tested and touted it to the rest of the world, which made many Russians hesitant to get vaccinated.
Sinovac’s Corona Vac
This is a traditional vaccine similar to the chickenpox or rabies vaccines that use inactive forms of the virus to trigger the body to form antibodies against the virus. This vaccine was developed in China and is currently being administered there along with Indonesia, Brazil, the Philippines, Thailand, and other Asian countries. Chinese officials argue that Corona Vac is superior to the mRNA vaccines being used in other parts of the world because mRNA vaccines are too new and there isn’t enough data to support that they work. However, the Chinese vaccine was barely approved because it only averages around 50.4% effectiveness and the cut off to be approved is 50%.
One can only hope that we will wake up from the nightmare that is the COVID-19 pandemic and the many vaccines that have been approved or have are in the final stages of testing can serve as a much needed alarm clock. To sum it up, the Pfizer and Moderna vaccines are very safe and effective and those that can should receive the vaccines as soon as possible so life can get more normal. Hopefully, more vaccines will be approved for the US to help us reach herd immunity faster and protect vulnerable populations in our community.