“The light at the end of the tunnel” is a popular term these days, with the FDA having approved three COVID-19 vaccines for emergency use (U.S. Food and Drug Administration). Pfizer-BioNTech and Moderna, two of the top six vaccines, received “emergency use authorizations” (EUAs) in December 2020, and Janssen Pharmaceuticals received a EUA in late February 2021. The other three vaccine candidates are hot on their heels.
Pfizer-BioNTech Announces 95% Effectiveness
Pfizer-BioNTech revealed in November 2020 that an independent review of their BNT162b2 vaccine found it to be safe and successful in preventing COVID-19. (The FDA advised drugmakers in June 2020 that the threshold is 50% effectiveness.) In “real-world” settings, that is, in individuals who are not part of the clinical trial, the vaccine is 90 percent successful.
The Pfizer-BioNTech vaccine is an mRNA vaccine that stimulates the immune system against the novel coronavirus by using genetic material known as messenger RNA (mRNA) encoding the virus’s spike protein (S protein). Both young and old research participants responded well to the two-injection vaccine. Although the upper limit on how long immunity can last is unknown, available evidence indicates that the COVID-19 defense may last a year or longer.
To stay safe, vials of the mRNA vaccine had to be held at subzero temperatures (-112oF to -76oF), which made transportation and storage difficult. However, the FDA recently declared that the vaccine can be held for two weeks in a regular freezer (0°F).
Moderna’s Vaccine Candidate Is 94% Effective
Moderna’s vaccine candidate also contains mRNA. Moderna and the National Institute of Allergy and Infectious Diseases collaborated on the mRNA-1273 vaccine (National Institute of Allergy and Infectious Diseases). It began phase I trials in May 2020 and soon progressed to phase II and phase III trials.
Centered on phase III clinical trial of 30,000 participants, the Moderna mRNA-1273 vaccine is 94.5 percent successful at preventing COVID-19. 90 cases of COVID-19 were found in the placebo population, while 5 cases were found in the mRNA-1273 group. There were eleven serious events, all of which happened in the placebo category. In real-world settings, the Moderna vaccine is 90 percent effective in preventing viral infection. The US government has agreed to fund the purchase of 200 million doses of the Moderna vaccine.
The Moderna vaccine, like the Pfizer-BioNTech mRNA vaccine, can be held in a regular freezer used in most medical offices and pharmacies.
Johnson & Johnson’s One-Dose Vaccine Is 66% Effective Overall
To make their vaccine candidate Ad26.COV2.S, Janssen, a division of Johnson & Johnson (J&J), uses the S protein gene from an inactivated cold virus. Their Ebola vaccine, which is now in operation in the Democratic Republic of Congo, uses the same technology. The Janssen vaccine, unlike the others, only needs one dose and can be kept in a normal refrigerator.
In June 2020, Janssen initiated phase I/II trials, and in September 2020, a massive phase III study of 40,000 participants began. After a single dose of the vaccine, phase III clinical trials in humans revealed that it is safe and 66 percent successful in avoiding mild to extreme COVID-19. The vaccine is 85 percent successful at avoiding serious COVID-19 infections and hospitalization-related complications.
The vaccine was approved by the FDA on February 27, 2021. 100 million doses will be given by Janssen.
Within three weeks after receiving the J&J vaccine, some patients experienced an uncommon yet dangerous form of a blood clot, as well as a low platelet count. J&J vaccines were halted by the CDC and FDA on April 13, 2021. They ended the pause after a careful analysis. The J&J vaccine now includes a precautionary statement regarding the possibility of blood clots and a reduced platelet count 1 to 2 weeks after vaccination. Females between the ages of 18 and 49 were the most likely to have blood clots and a reduced platelet count.
AstraZeneca And Oxford’s Vaccine Is 76% Effective
The coronavirus S protein gene of an inactivated common cold virus is also used in the AZD1222 vaccine (Vaxzevria) to enhance the immune system. The vaccine is 76 percent successful in phase III clinical trials in the United States.
The vaccine was approved for emergency use in the United Kingdom-based on previous phase III trials in the United Kingdom and other countries. The AstraZeneca vaccine is now being used in dozens of other countries, but the United States has not yet approved it for emergency use. According to the European Medicines Agency, there is a correlation between life-threatening blood clots arising within two weeks of AZD1222 vaccination, similar to the Janssen/J&J COVID-19 vaccine (equivalent to the U.S. FDA). While this adverse effect is very rare (222 cases recorded out of 34 million people vaccinated across Europe and the United Kingdom), it has been fatal in some cases.
The corporation has the capacity to produce 2 billion doses. The AstraZeneca/Oxford vaccine is less expensive than most vaccinations and only needs refrigeration for storage.
GlaxoSmithKline (GSK) is the largest vaccine manufacturer in the world. It has partnered up with Sanofi, another vaccine behemoth, to develop a COVID-19 vaccine. In terms of distance, they are behind the other top candidates. Their nominee is now undergoing human testing. Phase II/III trials will begin in February 2021, according to the company. It’s possible the vaccine clearance won’t come until the end of 2021.
They can make up for their lack of time in potency relative to the others. A viral protein-based vaccine with a vaccine adjuvant, equivalent to the flu shot, is their candidate. The adjuvant basically boosts the immune system’s reaction. The aim is to create an adjuvanted vaccine, which is a better vaccine. Herd immunity could be achieved faster if the immune response were better.
Sanofi-GSK has secured $2.1 billion in industrial grants from the United States government. This deal, and those of its kind, guarantees the United States 100 million doses. Sanofi has since reached agreements with the European Union, Canada, and COVAX, a multinational coalition, to ensure that COVID-19 vaccines are distributed fairly across the globe.
Novavax COVID-19 Vaccine Shows Up To 96% Efficacy
The Novavax vaccine is a protein-based vaccine with adjuvants, identical to the Sanofi-GSK vaccine. The vaccine was 96 percent effective in preventing COVID-19 caused by the initial COVID-19 strain in phase III clinical trial in the United Kingdom, and 86 percent effective against the B1.1.7 mutation discovered in that region. A separate study in South Africa revealed 60% effectiveness, owing to a special variant discovered there.
Additional phase III trials are currently being conducted by Novavax in the United States and Mexico. Novavax, like the other vaccines (except Pfizer-BioNTech), has a deal with the US government to supply 100 million doses if the EUA is approved.