COVID-19 vaccine combination. Why and which pairs are the most “compatible”?
The “informational reason” for this post is obvious – the signing of a memorandum of cooperation between the Center. Gamalea and AstraZeneca to develop vaccines against COVID-19. I could not find the text of this memorandum (if anyone knows, please tell me). While there is no specifics, one can speculate about why the Gamaleya Center and AstraZeneca decided to cooperate in such an extremely competitive area. I will immediately outline the boundaries of my reasoning. On the one hand, I narrow the topic, leaving out the PR, political and business aspects of this cooperation. On the other hand, I am expanding it – we will talk about combinations of various vaccines against COVID-19, and not just GamCovidVac and AZD1222.
There are two contexts for the use of COVID-19 vaccines. The first is “emergency” during an epidemic. In this case, the goal is to reduce the incidence of COVID-19, the severity of the disease and mortality, and the maximum program is to “repay” the epidemic. In this context, any vaccine that works towards this goal is suitable, even if its effect is short-lived. The second context will be relevant if the SARS-CoV2 infection “takes root” and the seasonal epidemics of COVID-19 become the same fact of life as the flu and SARS (it looks like this is coming).
With such a still hypothetical course of events, the factors that determine how long-lasting vaccine protection is, come to the fore. There are two complications here. The first is the variability of the virus. Fortunately, in this sense, SARS-CoV2 is a “good guy” – its variability and diversity are very small in comparison with the influenza A virus and rhinoviruses (the main causative agents of ARVI). Nevertheless, SARS-CoV2, like any virus, is constantly evolving and sooner or later there may be variants against which vaccines designed to combat the initial epidemic will be ineffective.
A combination of vaccines does not solve this problem. The fact is that all major vaccines against COVID-19 are made on the assumption that immune responses to the “canonical” variant of the viral protein S are sufficient for protection. In other words, if a resistant variant of the virus appears (which is unlikely in the short term), it will be a problem for all current vaccines. They will need to be modernized. This is an interesting topic, but not about that today.Поділитися цим: