Recently, many companies, including Pfizer-BioNTech and Moderna announced a new vaccine for COVID-19, which would be a huge advancement in combating the pandemic and could potentially save millions of lives. Yet, according to the Pew Research Center, 39% of American adults would probably or definitely not get the COVID-19 vaccine, and typically, 50% to 90% of the population must be immune to achieve herd immunity. However, misinformation about the vaccine is prevalent in the media, so what exactly are mRNA vaccines, and how safe is the new COVID-19 vaccine?
When were vaccines discovered?
While it may seem that vaccinations are a thing of modern technology, vaccines have been around for much longer than you may expect, as the concept of vaccines has been around since 1000, as it was reported that inoculation of smallpox sores into a person’s arm was a practice in early China.
However, the first actual vaccine was developed in 1796 by Edward Jenner when he inoculated an eight year-old boy with cowpox, a milder version of smallpox, using a cowpox blister of a milkmaid named Sarah Nelms. Jenner noticed that milkmaids who got cowpox were immune to smallpox, so while the boy did develop a mild fever, after exposing the boy to smallpox, the boy did not become sick with smallpox because he had gained immunity to smallpox.
While Edward Jenner used a different and milder virus to help the boy gain immunity to a more severe disease, most of the vaccinations now are categorized into four types, live-attenuated vaccines, inactivated vaccines, subunit, recombinant, polysaccharide, and conjugate vaccine, and toxoid vaccines.
What are the types of vaccines in development?
Currently, there are seven live-attenuated vaccines that uses a weakened form of the virus to trigger an immune response in the body, 14 protein subunit vaccines that use fragments of the virus to induce an immune response, 10 nucleic acid vaccines that provide cells with the instructions to make antigens within the body, and 13 viral vectors, which uses a harmless virus to deliver the nucleic acids to the cell.
The reason vaccines work is because of how the immune system works. In our body, we have an innate and adaptive immune system. The innate immune system is non-specific, so it responds first to an infection. However, while the adaptive immune system takes longer to respond, it can make antibodies that can specifically target pathogens that the body has come in contact with, so if the body is infected by the same pathogen for a second time, the adaptive immune system has specialized antibodies that can quickly defend the body from the pathogen.
Vaccines are meant to help the body develop antibodies against a specific pathogen by introducing a weakened form of the pathogen, so when infected by the regular form of the pathogen, the body will be able to defend itself because of the antibodies.
What is the mRNA vaccine, and is it safe? Are the Pfizer-BioNTech and Moderna vaccines a live vaccine?
The Pfizer-BioNTech and Moderna vaccine are both nucleic acid vaccines, since they use mRNA to help the body produce antibodies against the virus, which means they are not live vaccines.
However, what exactly are mRNA vaccines? Typically, many vaccines, including the measles, mumps, rubella (MMR) vaccine, use a weakened form of the pathogen to allow the body to develop antibodies against the virus. But this time, with the new COVID-19 vaccine, mRNA that encodes for proteins from the virus, and when this protein is transcribed, it causes an immune response in the body.
Specifically, this protein is a harmless piece of the spike protein, which are the protruding “crowns” that you see in depictions of the COVID-19 virus, and this protein is unique to viruses in the coronavirus family. In fact, “corona” means crown, so the virus is often referred to as the coronavirus because of the crown-shaped spikes.
Yet, with many other features of the virus, such as the envelope protein, lipid membrane, or membrane protein, why are scientists targeting the spike protein? As it turns out, the spike protein is responsible for the virus infecting its host, as it can latch on to the proteins, namely, the ACE2 receptor, on a human cell, allowing the virus to enter the cell. This essentially allows scientists to prevent infection by preventing the virus from even entering the cell, which is a crucial target for vaccines.
Unlike many other vaccines, the mRNA vaccine does not contain the entire COVID-19 virus, only the spike protein, so would be near impossible to get infected with COVID-19 from the mRNA vaccine. Dr. Thomas Kenyon, chief health officer at Project HOPE and former director of the CDC Center for Global Health, illustrates this when he states, “Nobody is getting infected with a COVID vaccine. It is only the surface protein that would be replicated because we have given you the messenger RNA. It is not the entire virus.” However, a common concern with the mRNA vaccine is the novelty of this method, as currently, there has never been any other mRNA vaccine approved for use for any disease.
“Nobody is getting infected with a COVID vaccine. It is only the surface protein that would be replicated because we have given you the messenger RNA. It is not the entire virus.”Dr. Thomas Kenyon, chief health officer at Project HOPE and former director of the CDC Center for Global Health
According to Anthony Komaroff, a professor of medicine at Harvard Medical School, some of the problems scientists encountered and solved when developing mRNA vaccines include, “First, scientists learned how to modify mRNA so that it did not produce violent immune system reactions. Second, they learned how to encourage immune system cells to gobble up the mRNA as it passed by in the blood. Third, they learned how to coax those cells to make large amounts of the critical piece of protein. Finally, they learned how to enclose the mRNA inside microscopically small capsules to protect it from being destroyed by chemicals in our blood.”
While the vaccine itself is rather new, the concept of mRNA vaccines isn’t new. In the 1990s, Hungarian biochemist Katalin Karikó proposed the idea of using mRNA to fight disease, but this idea was largely rejected by many scientists because the adverse reactions caused by the body were too risky. However, this problem was solved when the scientists invented a hybrid RNA that could avoid detection by the immune system, and since then, mRNA vaccines have come a long way.
Currently, the Pfizer-BioNTech vaccine was found to have a 95% efficacy rate, while the Moderna vaccine is 94.5% effective. This is an incredible efficacy rate, as the FDA previously stated that it would authorize a vaccine with just a 50% efficacy rate. However, a consequence of using mRNA vaccines is the difficulty in storing the vaccine, as the Pfizer-BioNTech vaccine must be stored at minus 94 degrees Fahrenheit, while the Moderna vaccine must be stored at minus 4 degrees Fahrenheit.
The COVID-19 vaccine was developed in record time. Is it safe?
Another concern many people have over the new COVID-19 vaccine is the record time it took for development and approval, as the quickest vaccine to be developed was the mumps vaccine, which took four years in the 1960s. However, scientists have been studying coronaviruses for much longer, as the severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS) epidemic in 2003 and 2012 respectively, and the common cold virus are all coronaviruses, which contributed to our knowledge as scientists have been studying coronaviruses for over 50 years, and this helped develop the COVID-19 vaccine.
In addition, the finances of developing a vaccine is a huge issue in vaccine development, as the process for developing a vaccine for epidemic infectious diseases can often cost between $31-68 million according to an estimate published in The Lancet Global Health Journal. However, during the COVID-19 pandemic, many government and private programs helped provide the funding necessary to develop a vaccine quickly.
For example, Operation Warp Speed (OWS) in the United States worked to produce and distribute 300 million doses of safe and effective vaccines for COVID-19 by January 2021. This was done in partnership with the Department of Health and Human Services, and by providing funding for pharmaceutical companies to develop COVID-19 vaccines, Operation Warp Speed was able to accelerate the development, testing, and distribution of the COVID-19 vaccine.
While clinical trials can often take over five years, the Pfizer-BioNTech and Moderna vaccine was approved by the FDA in less than a year. Most clinical trials consist of three stages: Phase I, which tests for safety and efficacy with a small group of people, Phase II, which has around 100 study participants, including those with preexisting health conditions, such as obesity, diabetes, or cancer, and Phase III, which continues to test for safety and efficacy with thousands of people in the trial.
However, while many drug trials can take years, this can often be due to the lack of study participants or funding. Moderna’s clinical trials had 30,000 participants, and out of those, 37% were people of color. Pfizer-BioNTech had over 40,000 participants, with 30% of the participants being people of color.
In comparison, the typical number of participants in Phase III of a clinical trial is a couple hundred to 3,000 people. Clearly, the number of participants in the COVID-19 vaccine trial is significantly higher, which allowed the scientists to collect large amounts of data. In addition, during the clinical trials for the COVID-19 vaccine, some of the phases were combined into Phase I/II or Phase II/III, which saves time with clearances.
While many people are concerned about whether or not safety measures were sacrificed in order to save time, the pharmaceutical manufacturers have to follow at least half of the study participants for at least two months after the vaccination, and in addition, the FDA, CDC, Advisory Committee on Immunization, and Mayo Clinic are all responsible for evaluating the safety and efficacy of the vaccine.
Who will need the COVID-19 vaccine? How much of the population must be immune to achieve herd immunity?
As the supply of the COVID-19 vaccine is limited, healthcare workers and those who live in long-term care facilities and are at highest risk of catching COVID-19 will be the first to receive the vaccine. After that, other frontline workers, people over 75 years old, and those with underlying health conditions will be able to get the vaccine. It is estimated that the vaccine will become accessible to everyone by late May of 2021.
However, Dr. Anthony Fauci, the director of the National Institute of Allergy and Infectious Diseases, recommends postponing large gatherings until 2022, as herd immunity will take a while to develop.
Speaking of herd immunity, in the beginning of the pandemic, misconceptions about herd immunity began spreading, particularly on social media platforms like Facebook, as some users began recommending “COVID-19 Exposure Parties” to quickly gain herd immunity. This may be due to “chickenpox parties” that occured before the chickenpox vaccine was developed in 1995, which was a gathering for parents to deliberately infect their children with chickenpox so the children could gain natural immunity to the disease.
However, while some people suggest hosting “COVID-19 Exposure Parties,” COVID-19 is a severe disease that can cause serious symptoms and even death, so these parties are risky as there’s no way to predict what might happen. Some countries, such as Sweden, attempted to handle COVID-19 through herd immunity by allowing bars, schools, restaurants, salons, and gyms to stay open, but the death rate of over 80 in 100,000 people in Sweden, this turned out to be one of the highest in Europe.
According to Johns Hopkins University, 70% to 90% of the population must be immune before we can gain herd immunity, which is unlikely to be achieved by gambling with a severe disease and causing a spike in hospital cases. The goal of herd immunity is to have most of the population immune to the virus, so the virus is unable to spread in the population, which protects vulnerable groups of people who are unable to get the vaccine.
What will happen with the new mutated virus that was discovered in the U.K?
Despite the success of the vaccine, scientists recently discovered a mutant of COVID-19 called B-117 that may be more contagious than the original virus. While it’s not a surprise that viruses mutate, this mutated virus is important because it may increase the virus’ ability to infect host cells by 70%.
In addition, the mutated virus has 8 mutations that occur on the spike protein out of the 17 total mutations, and these mutations may improve the binding ability of the virus to host cells. However, according to Dr. Anthony Fauci, current data suggests that the Pfizer-BioNTech and Moderna vaccine is still effective against the mutated virus, despite the mutations on the spike protein. But for pharmaceutical companies Eli Lilly and Regeneron, the mutations are close to the target of the vaccine, which is a monoclonal antibody vaccine.
Nevertheless, the current vaccines for COVID-19 have still been shown to be effective against the new mutations, although it’s unclear what may happen in the future if the virus mutates into a different form.
With the new COVID-19 vaccine coming out in record time, many people have concerns over the safety and efficacy. However, clinical trials, regulatory agencies, and further testing have all proven the vaccine to be safe and effective. Despite the new mutations that have recently come into light, recent data suggests that the vaccine is still effective against the mutated virus, although it’s unclear how the virus may continue mutating in the future. One thing’s for sure though, it’s unlikely that the vaccine will be able to cause the disease, since it only contains part of the virus. While there are still many unanswered questions about COVID-19, the development of the vaccine provides a new hope for combatting the pandemic.
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