Today we heard the news that a third vaccine has excellent data showing effectiveness, along with good safety data. The Astra Zeneca vaccine has a different approach than the first two vaccines we heard about. It uses a “live attenuated virus” which is a weakened version of a cold virus that has some genetic material imbedded, similar to the spike protein on the Coronavirus. After injection, the body makes an immune response to that spike protein which will then be able to attack the SARS-CoV-2 virus if someone were to be exposed.
Interestingly, they found that if they used a 1/2 size dose for the first injection and then a full dose a month later the response was 90% effective, compared to a smaller response of only 62% if they used two full doses. This means it can potentially be used on more people since lower doses are needed. This approach is cheaper because this is not new technology. Another big advantage is that it doesn’t have to be frozen, but can be kept in a fridge. This is huge when it comes to logistics, especially in poorer countries.
The other two vaccines are m-RNA vaccines, a new approach to vaccines, which don’t use live attenuated viruses, but use the bodies own immune system to create the response. The m-RNA is also known as messenger RNA which is a single strand that instructs a cell to make proteins. An m-RNA vaccine works by entering a cell after injection and teaching that cell to make the spike protein so the body then can recognize the virus and defend against infection. This is a very informative article that describes the process. Even though this is a new approach, the safety concerns are low because the m-RNA degrades pretty quickly after its initial work is done. The other advantage to the m-RNA approach is that it can be quickly adapted to different viruses so that a new vaccine can be developed quickly for new viruses as they emerge.
These are very promising and Pfizer applied for approval yesterday. The biggest issue with these two m-RNA vaccines is distribution since they both need to be frozen, with the Pfizer needing to be minus 70 degrees. They are also more expensive per dose.
Do we really need 3 vaccines for the same disease? That is a good question, but with COVID-19 raging right now in so many countries, not just the US, having 3 companies able to pump out millions of doses is a good thing. It means many more people will have a chance to be immunized more quickly. Plus it gives us a back up if one of the vaccines has issues develop that haven’t been seen yet, as well as back up to the manufacturing of vaccines if any of the manufacturing processes get blocked.
But the bigger issue is uptake by people. Will enough people opt in to get a vaccine to bring herd immunity? So much is at stake. Many people are skeptical because of the politicization of the vaccine process. Were they pushed through too quickly so that safety was shortchanged? The Lancet, a British medical journal, has an editorial reminding us of the stakes and the importance of integrity. Even many health care providers have a healthy dose of hesitancy regarding the process, wanting to make sure the integrity and safety of the studies are kept to a high standard. And many other communities, especially blacks, already have hesitancy regarding safety and effectiveness of vaccines.
We will need as many people as possible willing to get a vaccine to make vaccines work, so taking our time and ensuring safety is key. Having choices is good. It can help if we all study and learn about the choices so we can make an informed decision and help our friends and family do the same. You can read about the different vaccines in this New York Times article that is tracking the vaccines.
Wash your hands, cover your nose, keep safe six, stay informed
And finally, my caveat is that this is my experience and my opinions, which are subject to change as more information is available, and not related to the organization I work for. Thanks for reading.