With the current global pandemic, many companies have been in a race to complete a vaccine. The past couple of weeks have been an important time for announcements and developments on this front, so here’s a breakdown of the most promising vaccines.
Pfizer
How does it work? Pfizer’s COVID vaccine is mRNA-based. If approved, it will be the first mRNA vaccine on the market. mRNA is messenger RNA, small segments of genetic material that deliver a message to create proteins. These proteins are very specialized and will trigger the immune system to respond to the coronavirus. Traditional vaccines use simplified versions of a virus, which can make some people contract the virus, and could make people hesitant to want the vaccine. A benefit of the mRNA vaccine is that it doesn’t use weak forms of the virus, ostensibly making it safer and reducing side effects.
When will it be ready? The vaccine was announced on November 9 and Pfizer estimates that it’ll be available within two months, pending its approval by the FDA. They filed for emergency authorization on November 20, and since they filed first, they will likely be the first vaccine approved, which could be as soon as December. Pfizer says they should be able to produce 50 million doses in 2020 and up to 1.3 billion doses in 2021. It will go first to doctors and nurses, then to those most at risk, and then to the general public. It’s estimated that this vaccine will be readily available between March and May 2021.
Efficacy rate? Over 90% effective.
Moderna
How does it work? The Moderna vaccine is also mRNA based and works by using the mRNA to produce antibodies to defend against the virus. Antibodies are essentially tiny bombs that attach to infected cells and kill them, stopping the spread of the virus. The viral code used recognizes the shell around the coronavirus and it teaches the immune system to recognize the live virus and respond accordingly.
When will it be ready? Moderna announced their version of a COVID vaccine on November 16 and plans to file for an emergency approval from the FDA by the end of November. The FDA’s data review will be on December 17. If approved, Moderna will have vaccines to distributors within 24 hours and people should begin to be vaccinated within 2 days. Moderna has said they’ll be able to produce 20-40 million doses by the end of 2020.
Efficacy rate? Recent Phase 3 trials from Moderna report it is 94.5% effective.
AstraZeneca
How does it work? The AstraZeneca vaccine is an “adenovirus vector vaccine,” meaning it uses a genetically engineered virus. It takes a common cold virus found in chimpanzees and has a gene inserted to increase the immune response. This method is most similar to typical vaccines that are widely on the market today.
When will it be ready? This vaccine was announced on November 23, and AstraZeneca has said that they could have 4 million doses ready by the end of the year, again pending FDA approval. They’ve also said that they can produce 40 million doses by the first quarter of 2021.
Efficacy rate? Up to 90% effective. However, AstraZeneca’s vaccine efficacy has recently come under fire after new details of their trials were released. The efficacy rate varied from 62% to 90%, with an average of 70%. Additionally, some participants received a half dose, which was a mistake not outlined in the study. With this new information, it’s likely emergency approval of this vaccine will be delayed until further testing can be conducted.
Sources:
Comentários