Vaccines
Emma Raffman
April 27 2021
April 27 2021
To end the COVID-19 pandemic, development of an effective vaccine is paramount. Vaccines are a preventative measure against the contraction of a virus. They work by mimicking the virus they protect against, thereby training the immune system to fight off the virus before the virus even enters the body. Vaccines specifically work by facilitating the entrance of antigens inside the body. Antigens are simply any foreign substance that can cause an immune response. In the case of SARS-CoV-2 (the virus that caused the COVID-19 pandemic), the antigens of the virus are any portion of the virus that the body uses to recognize that it is an invader. Part of this immune response is the formation of antibodies. Antibodies are the proteins responsible for killing the virus and for recruiting other parts of the immune system against the virus. They also come in many different types, each of which is specific to the virus it protects against. Therefore, by introducing antigens into the body, vaccines are able to stimulate the body to produce cells containing the specific antibodies that work against any virus containing the specific antigen. These cells are stored in the immune system, so if the inoculated person ever encounters the actual virus, the body is already equipped to deal with it. The immune response is much faster and more pronounced than if vaccination did not occur because without the vaccine, the body would have to produce new antibodies from scratch.
To create a vaccine against COVID-19, researchers have targeted the COVID-19 spike protein antigen, a key protein on SARS-CoV-2 that helps the virus enter human cells. However, several vaccine candidates have employed different methods to recreate this spike protein including mRNA vaccines, deactivated virus vaccines, and viral vector vaccines.
mRNA vaccines have proven surprisingly effective against COVID-19. mRNA is formed from DNA. Like DNA, mRNA contains genetic information from which cells are able to synthesize proteins that allow human cells to live and function properly. COVID-19 mRNA vaccines contain the blueprints for constructing the COVID-19 spike protein; innate machinery follows this blueprint to generate the spike protein. Afterwards, the mRNA is immediately degraded, meaning it breaks down and does not stay in the cell. Hence, the mRNA has no lasting effects on the body.
mRNA vaccines are a relatively new technology; they have never been implemented before but they are proving surprisingly effective with no reports of major side effects. The two leading mRNA vaccines candidates made by Pfizer/BioNTech and Moderna have reported 95% and 94% effectiveness respectively in Phase III trials which were carried out among thousands of participants. Effectiveness is a measure of how well the vaccines protect someone from contracting the virus. The vaccines performed even better at preventing hospitalizations and deaths resulting from the virus. Both vaccines have been approved by the U.S. Food and Drug Administration (FDA) and administration of the vaccines began in early December 2020 to primarily healthcare workers and at-risk populations. Two doses (shots) of both the Pfizer and Moderna vaccines are required to attain COVID-19 immunity.
To create a vaccine against COVID-19, researchers have targeted the COVID-19 spike protein antigen, a key protein on SARS-CoV-2 that helps the virus enter human cells. However, several vaccine candidates have employed different methods to recreate this spike protein including mRNA vaccines, deactivated virus vaccines, and viral vector vaccines.
mRNA vaccines have proven surprisingly effective against COVID-19. mRNA is formed from DNA. Like DNA, mRNA contains genetic information from which cells are able to synthesize proteins that allow human cells to live and function properly. COVID-19 mRNA vaccines contain the blueprints for constructing the COVID-19 spike protein; innate machinery follows this blueprint to generate the spike protein. Afterwards, the mRNA is immediately degraded, meaning it breaks down and does not stay in the cell. Hence, the mRNA has no lasting effects on the body.
mRNA vaccines are a relatively new technology; they have never been implemented before but they are proving surprisingly effective with no reports of major side effects. The two leading mRNA vaccines candidates made by Pfizer/BioNTech and Moderna have reported 95% and 94% effectiveness respectively in Phase III trials which were carried out among thousands of participants. Effectiveness is a measure of how well the vaccines protect someone from contracting the virus. The vaccines performed even better at preventing hospitalizations and deaths resulting from the virus. Both vaccines have been approved by the U.S. Food and Drug Administration (FDA) and administration of the vaccines began in early December 2020 to primarily healthcare workers and at-risk populations. Two doses (shots) of both the Pfizer and Moderna vaccines are required to attain COVID-19 immunity.
Image Source: geralt
The Johnson & Johnson vaccine has also been approved by the U.S. FDA as of late March 2021. It has reported 66% effectiveness, less than both mRNA vaccines. However, and more importantly, the Johnson & Johnson vaccine has reported no deaths or hospitalizations from inoculated subjects. The Johnson & Johnson vaccine also requires only one dose. It also is much easier to store than both of the mRNA vaccines, which both have to be kept frozen at temperatures at or below -15 degrees Celsius. These facts make the Johnson & Johnson vaccine much easier to distribute, despite its lower effectiveness. The Johnson & Johnson vaccine is different from the mRNA vaccines. It is a viral vector vaccine. Viral vector vaccines simply attach the spike protein antigen onto a different, non-harmful virus to facilitate entry of the antigen into the body at no risk to the patient. Since the Johnson & Johnson vaccine received FDA approval in late February, the company plans to begin administration of the vaccine almost immediately and expects to provide nearly 10 million doses by the end of the same month.
On April 13, 2021, the CDC and FDA temporarily halted the production and use of the Johnson & Johnson vaccine due to six reported cases in the U.S. of rare and severe blood clots in patients who have received the Johnson & Johnson vaccine. All six cases were in women aged 18 to 48 who started showing symptoms 6 to 13 days after receiving the vaccine. The pause was declared out of abundant caution and these symptoms are extremely rare, so the vast majority of people who have received the Johnson & Johnson vaccine have no reason to worry. As of April 23, 2021, the CDC and the FDA have recommended that the Johnson & Johnson vaccine can once again be manufactured and distributed in the United States. According to these authorities, the benefits of vaccinating people against COVID-19 are much more significant and outweigh the small risk of serious side effects. If offered the Johnson & Johnson vaccine, one should monitor for severe symptoms for about three weeks as a precaution.
Hopefully, these vaccines will continue to be administered quickly to healthcare workers, at-risk populations, and finally the general public to achieve herd immunity and end the COVID-19 pandemic.
On April 13, 2021, the CDC and FDA temporarily halted the production and use of the Johnson & Johnson vaccine due to six reported cases in the U.S. of rare and severe blood clots in patients who have received the Johnson & Johnson vaccine. All six cases were in women aged 18 to 48 who started showing symptoms 6 to 13 days after receiving the vaccine. The pause was declared out of abundant caution and these symptoms are extremely rare, so the vast majority of people who have received the Johnson & Johnson vaccine have no reason to worry. As of April 23, 2021, the CDC and the FDA have recommended that the Johnson & Johnson vaccine can once again be manufactured and distributed in the United States. According to these authorities, the benefits of vaccinating people against COVID-19 are much more significant and outweigh the small risk of serious side effects. If offered the Johnson & Johnson vaccine, one should monitor for severe symptoms for about three weeks as a precaution.
Hopefully, these vaccines will continue to be administered quickly to healthcare workers, at-risk populations, and finally the general public to achieve herd immunity and end the COVID-19 pandemic.
Featured Image Source: qimono
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