That has been a common question I have heard since they became available the first part of September. These vaccines have broader coverage that include Omicron sub-variants. So, it makes sense they should work better than the original vaccine. However; when the updated vaccines were released, we did not have a lot of data about the actual effectiveness of these vaccines. We are now accumulating data and the studies are very encouraging.
By necessity, these vaccines could not be tested on large numbers of people in long-term trials. We did not have the luxury of having large, long-term, randomized control trials to determine effectiveness before they were authorized. At the time the decisions were being made on authorizing these vaccines; we were looking at a potential big wave of infections, hospitalizations and deaths going into the fall and winter.
This wave of COVID-19 disease is going to be compounded by what has already become a bad influenza and RSV season. Larger hospitals in Nebraska and many other states are already having long waiting lists for transfers of patients needing care that is not available at smaller facilities. Last fall and winter we found our hospital systems severely overwhelmed. People in need of critical care spent days waiting for transfers to facilities with the capabilities to treat them. Larger hospitals had patients sitting in ER hallways for days waiting to be admitted. This has affected not just those with COVID-19 but everyone else in need of medical care. We hope that giving people a COVID-19 booster with broader protection will help us alleviate some of this suffering.
As we have encountered each of the successive waves of new SARS-CoV-2 variants we have found that the original vaccine has become somewhat less effective for shorter periods of time. People getting vaccinated for the first time right now with the original vaccine likely have fair protection against severe disease however those who have not had a COVID-19 vaccine for several months are at higher risk for infection and even severe disease. The same goes for those who were infected with previous variants of the virus; the variable protection one gets from surviving infection from one variant is less likely to keep from getting sick or ending up in the hospital with the next variant.
One of the advantages of the mRNA vaccines is that you can very quickly adapt to changing virus variants. Vaccine developers very early on in the pandemic had been working towards developing vaccines that are able to provide broader protection against the changing variants. For example; as early as April of 2021, researchers working with Moderna had started a human clinical trial on vaccines with broader protection. In September of 2021 they published an interim analysis of the data from their human clinical trials showing encouraging results.
In early 2022, human clinical studies were being conducted on vaccines that provided broader protection against the Omicron sub-variant that was dominant at that time. The results suggested better protection against the Omicron sub-variant BA.1 with an excellent safety profile. However, by the time the studies were done we were seeing the rise of Omicron sub-variants BA.4 and BA.5.
But all was not lost. Moderna at least had in their study reported that their updated vaccine had a fair response to BA.5 as this was one of the sub-variants they tested the vaccine against. The Omicron sub-variants BA.1 and BA.5 are not much different genetically - the vaccine they were testing still worked OK.
So, the vaccine developers didn’t have to scrap everything and go back to the drawing board - they were simply able to make a few small changes in the mRNA sequences that would code for the instructions for the binding protein of the BA.4 and BA.5 sub-variants. This allowed vaccine developers during the summer of 2022 to get the updated vaccine ready to go in time for the fall. Studies were done on the immunogenicity of the vaccines against the new sub-variants with results suggesting they should work, and the vaccines were rolled out quickly to get ahead of the next wave. It is important to note that all this time human clinical trials were being conducted, the results of which are now being peer reviewed and published.
In the link below you can access references to these studies and other supplemental information. My hope with this article and the supplemental information on the website is to provide information for you to better understand the updated bivalent vaccines. If you have additional questions about if you should get the updated vaccines, I encourage you to discuss your personal health situation with your primary care provider or a medical provider knowledgeable about COVID-19 vaccines.
If you are ready to get vaccinated go to vaccines.gov to find a location to get it done.
Russ Coash, PA-C
All statements in this article should be attributed to myself, not any organization I represent or my employer. This article presents a medical perspective - not a statement intended to be for or against any public policy or politician.
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