After many long months of the COVID-19 pandemic, the Center for Disease Control and Prevention has endorsed two different COVID-19 vaccines to fight the spread of the virus. Here’s what you should know about each of these options:
- Pfizer-BioNTech COVID-19 Vaccine: On December 11, 2020, the U.S. Food and Drug Administration (FDA) issued its first emergency use authorization (EUA) for administration of the Pfizer-BioNTech vaccine.[1] This vaccine is safe for individuals aged 16 and older who are not knowingly allergic to any of the components of the vaccine. It requires two injections (0.3mL each) 21 days apart. Clinical trials showed that reactogenic symptoms were common, but rarely severe, and that symptoms generally followed the second injection. The most common side effects were local pain, swelling, and redness, as well as chills, tiredness, and headache.[2]
The Pfizer-BioNTech COVID-19 vaccine was the first mRNA vaccine to receive FDA approval within the United States. It is a lipid nano-particle formulated, nucleoside-modified transcript for the prefusion spike glycoprotein of SARS-CoV-2.[2]
Over 43,000 participants were tested in Phase II and Phase III clinical trials to provide data on the efficacy of the Pfizer-BioNTech Vaccine. The vaccine has been shown to be 95 percent effective in populations that have not previously contracted COVID-19; efficacy remained consistent across age, sex, and ethnic categories.[2] However, one large obstacle facing distribution is that the vaccine must be stored at temperatures of -94°F, which means the availability of a super freezer limits which clinics can safely store and administer the vaccine.
- Moderna COVID-19 Vaccine: A week after the Pfizer vaccine received FDA endorsement, the Moderna vaccine (also known as mRNA-1273) also gained official approval. The serum was developed jointly by the biotechnology company Moderna and National Institute of Allergy and Infectious Diseases. It is only recommended for administration in individuals 18 and older and has near-equivalent effectiveness to the Pfizer vaccine.[3]
The Moderna vaccine also uses an mRNA design but differs from the Pfizer vaccine in a few ways. For example, the mixture of lipids within the serum is distinct, which is thought to be the reason why the storage temperature is much more moderate. Supplies of mRNA-1273 have the distinct advantage of only needing to be kept at -4°F, the temperature of a normal freezer.[3]
Like the Pfizer vaccine, the Moderna vaccine requires two injections (28 days apart), and side effects are common but mild. Approximately half of individuals report symptoms following injection. Each dose is approximately 100mg. By the end of March 2021, Moderna estimates that up to 100 million doses will be available to the U.S.[3]
Given that the two COVID-19 vaccines have been rigorously studied and are highly efficacious, production capacity will likely continue to expand in order to meet global demand. At the same time, other vaccines are being considered for approval from the FDA; it is likely that additional options will be available in coming months.
References
[1] Commissioner, O. O. (2021). Pfizer-BioNTech COVID-19 Vaccine. Retrieved from https://www.fda.gov/emergency-preparedness-and-response/coronavirus-disease-2019-covid-19/pfizer-biontech-covid-19-vaccine
[2] The Advisory Committee on Immunization Practices’ Interim Recommendation for Use of Pfizer-BioNTech COVID-19 Vaccine – United States, December 2020. (2020, December 17). Retrieved from https://www.cdc.gov/mmwr/volumes/69/wr/mm6950e2.htm?s_cid=mm6950e2_w
[3] U.S. CDC Advisory Committee on Immunization Practices Recommends Vaccination with Moderna’s COVID-19 Vaccine for Persons 18 Years and Older. (n.d.). Retrieved from https://investors.modernatx.com/news-releases/news-release-details/us-cdc-advisory-committee-immunization-practices-recommends
