COVID-19 vaccines are considered the most promising path to curbing the pandemic and are being followed aggressively. More than 40 candidate vaccines are in human trials as of fall of 2020 and more than 150 are in preclinical trials. As vaccines are applying and being granted for emergency use authorization (EUA), the more misleading information that we become victim to. Worldwide vaccines are being manufactured. We will be covering three different types of vaccines and five dominating companies producing them. Trial vaccines (clinical trials), administration and symptoms/side effects are the three things we must educate ourselves on to make the right decisions. The development of vaccines progresses through preclinical assessment and three distinct clinical stages, phases I, II and III.
As of November 24, 2020, large-scale (Phase 3) clinical trials are in progress or being planned for five COVID-19 vaccines in the United States:
- AstraZeneca’s COVID-19 vaccine
- Janssen’s COVID-19 vaccine
- Moderna’s COVID-19 vaccine
- Novavax’s COVID-19 vaccine
- Pfizer’s COVID-19 vaccine mRNA vaccines contain material from the virus that causes COVID-19 that gives our cells instructions on how to make a harmless protein that is unique to the virus. Immune responses include killer T cells, which destroy infected cells and involve antibody-producing B cells and helper T cells which support antibody production.
Moderna’s mRNA vaccine (mRNA 1273) against COVID-19 entered clinical trials within two months of the SARS-CoV-2 genome being sequenced. Pfizer and Moderna, have revealed encouraging preliminary results, raising expectations in the U.S. and abroad that the end of the pandemic could be in sight. The Food and Drug Administration authorizes the vaccines, distributing them poses a formidable challenge. Both Pfizer and Moderna rely on messenger RNA, to cause the immune system to produce protective antibodies.
The Pfizer vaccine BNT162b2 (BioNTech and Pfizer) needs to be kept extremely cold at minus 70 degrees Celsius, which is colder than winter in Antarctica. Moderna vaccine still needs to be frozen, but only at a temperature of minus 20 Celsius, more like a normal freezer.
Protein subunit vaccines include harmless pieces of the virus that cause COVID-19. Novavax specializes in the development of subunit vaccines. NVX‑CoV2373 is a stable, prefusion protein antigen derived from the genetic sequence of the SARS-CoV-2 coronavirus spike (S) protein and adjuvanted with Novavax proprietary Matrix‑M™.
Vector vaccines contain a weakened version of a live virus, a different virus than the one that causes COVID-19. AstraZeneca and Oxford University’s potential COVID-19 vaccine is a viral vector vaccine. This vaccine is ChAdOxncoV-19/AZD1222 (University of Oxford, AstraZenca, and the Serum Institute of India are jointly involved)
More than one shot is required for most COVID-19 vaccines. Building protection begins with the first shot. To get the most safety the vaccine has to offer, a second shot is required a couple of weeks later. Since vaccine doses will initially be small, immunization managers around the country will need to have plans to administer all available vaccine doses.
In the first few hours after vaccination, symptoms/side effects usually appear and resolve within 24 to 36 hours. Symptoms are common and indicate that immunity is being developed by the body. Based on preliminary results side-effects are fever, fatigue, headache, muscle pain, joint pain, pain, and redness at the injection site. The effects are more frequent after the second dose. One vaccine in Phase 3 clinical trials only needs one shot. Unlike some of its competitors, Johnson & Johnson’s vaccine (Janssen) does not need to be frozen and may require just one shot instead of two. None of these vaccines can give any individual COVID-19.
Currently, Messenger RNA vaccines, protein subunit vaccines and viral vector vaccines are the three major forms of COVID-19 vaccines that have undergone large-scale (Phase 3) clinicals in the United States. Established active and passive surveillance systems are being enhanced in the United States to closely examine the safety of SARS-CoV-2 vaccines.