Winter is approaching and COVID-19 infections are increasing. Specialists in several countries recommend getting vaccinated again. However, this is not about immunizing ourselves with a booster but with an update of the formula.

Countries in the northern hemisphere such as the United States, China, France, and the United Kingdom are getting ready to vaccinate their populations again, although in some cases only for the elderly or people with chronic diseases.

Gloria Aguirre, an infectious disease specialist at the TecSalud Epidemiological Surveillance Unit, points out that it is necessary for all people over six months of age, with or without previous illnesses, to be vaccinated.

“More than a booster, it is considered a new vaccine, because it is not one of the previous ones but an updated one. It is called the XBB monovalent vaccine, which acts against a subvariant of Omicron.”

Both Moderna and Pfizer developed a new vaccine that has already proven to be effective against the new variant of SARS-CoV-2 that is now infecting the population in the United States.

“The recommendation would be that, if we have access to the updated vaccine, it would good idea to apply it, because most of us haven’t had doses for more than a year,” explains Aguirre.

For the specialist, it is evident that the vaccine against COVID-19 will be modified, most likely once a year based on the strains that are circulating.

When will COVID-19 booster shots be applied in Mexico?

In Mexico, for example, there was a slight upturn in cases during the summer, which did not raise the alarm for the authorities. This happened between June and July, when confirmed cases increased by 10.8%.

However, the Ministry of Health (SSA in Spanish) reported that they will be applying booster shots for the winter season, firstly among the elderly population and those with chronic diseases such as diabetes or cancer. These shots will be the Russian vaccine Sputnik and the Abdala vaccine developed in Cuba.

The problem for Dr. Aguirre is that there is no scientific evidence of these vaccines being effective against the new strain of COVID, so it cannot be predicted whether they will work or not.

“There are no studies. They may provide some protection, which is perhaps not optimal. It’s what’s available in our country. If there’s no access to any other vaccines except these (Sputnik and Abdala) and we haven’t had a shot of the vaccine for more than a year, it’s better than nothing,” explains Aguirre.