The first vaccines were produced against the virus strain that appeared in China, specifically in Wuhan. However, the virus has undergone evolution since then, and now its structure has changed so much that it is worth adapting vaccines accordingly. The so-called Omicron variant is currently contagious around the world. The first is called BA.1.
This variant caused the vast majority of injuries that occurred last winter. The American company Moderna, which is considered a leader in the production of vaccines, has now developed a vaccine against this. However, it did not stop there, the new vaccine already contains information on two strains of viruses, so technically it is called a bivalent vaccine.
In order to facilitate understanding, it may be useful to compare the situation with influenza, which has been known for decades. The influenza virus, similar to the new type of coronavirus, also mutates very quickly, and several sub-variants are known. Each year, this virus causes several million infections, hundreds of thousands of deaths, and an incredible amount of material damage due to the temporary disability of those infected. That is why it is recommended in practically all developed countries, and in some cases it is mandatory there. Since the virus mutates so rapidly, annual booster influenza vaccination is recommended, the composition of which is adjusted each year for the current influenza virus. However, for some time, the flu vaccine also contained not one, but three or four strains of the virus.
In fact, the battle and situation against the new type of coronavirus can now be compared to this, at least in general terms. The virus appears to be with us, at least for now, and will likely re-attack seasonally in the form of a new variant. At present, this appears to be the most likely diagnosis. For this reason, vaccine manufacturers are trying to develop new vaccines that can be given each year and adapt them to the variant causing the epidemic. The first representative of this is the aforementioned Moderna vaccine, which therefore contains the original variant and the omicron variant BA1. This has already been approved by the British authorities, and vaccinations will begin soon. Great Britain’s Medicines Authority has been at the forefront of testing the first coronavirus vaccines, followed by the European Union and the US Medicines Agency.
Now, however, it appears that the US authorities will follow a slightly different path.
Abroad, the authority has also voted in favor of bivalent vaccines, that is, containing two viruses, but unlike the vaccine approved by the British Medicines Agency, this Omicron will contain two newly isolated variants, namely BA4 and BA5. They currently account for the vast majority of infections in the United States. By the way, everyone over the age of 50 is advised to receive a booster dose with the current vaccines. However, those who are younger than this and do not have a chronic disease are better off, according to the authorities, if they wait for the next two-component vaccine against the current variants of Omicron.
A decision by the European Union Medicines Authority on this matter is expected in the coming weeks. Vaccinations in our country can begin after that, according to the manufacturers, even in October.
So it seems that
While Pfizer has won the competition for the first coronavirus vaccines, at least in chronological order, the situation has now reversed and Moderna could roll out the booster early.
The delay is likely not to be much, and a Pfizer license is also expected soon.
So the situation is constantly changing, and in light of this, science is also trying to evolve and keep pace.
The author specializes in allergy and clinical immunology, c. professor.
(Cover photo: Alain Jocard / AFP)
