How long do Covid-19 vaccines protect you for
How long the protective effect of Covid-19 vaccines lasts is still unknown. (Photo: iStock)

If the entire Mexican population were vaccinated against the SARS-CoV-2 virus, this wouldn’t necessarily mean that the protective effect lasted forever.

“What will happen? We won’t be able to measure how long the vaccines protect us for until a sufficient percentage of the population has been vaccinated,” says Ramón Antonio González García Conde, President of the Mexican Society of Virology, in an interview for Tec Review.

Covid-19 variants, such as the one that emerged in the United Kingdom or those detected in South Africa and Brazil, are one factor that could mean vaccines against this disease have a limited protective effect, as González García Conde explains:

“What could happen is that although the vaccines protect against almost any of the variants, they don’t provide as much protection, so immunity wouldn’t be as strong or long lasting. However, they may provide almost the same level of protection or offer protection that doesn’t stop you getting infected, but that does prevent your symptoms from becoming severe. That’s almost the same as being protected.”

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Will it stay or will it go away? The two paths for the pandemic

The scientist adds that the current pandemic could turn into something like the seasonal flu virus, in terms of applying a vaccine that’s been tailored to new, predominant variants.

“One possibility is that Covid-19 becomes a seasonal phenomenon. So, we would have to look at the most common variants in different regions of the world every year in order to produce the corresponding vaccines. The other course is that the pandemic disappears once a sufficient number of people have built up immunity against this virus. We would still see small, localized, epidemic outbreaks, but it would no longer be of pandemic proportions,” says González.

This specialist says that influenza is seasonal because it changes much faster than Covid-19, i.e. it’s much easier for variants of that virus to emerge for which there’s insufficient immunity in the population.

“Covid-19 changes at a slower rate than influenza does. This could be good news, but we don’t know yet. Only a short amount of time has passed in epidemiological and biological terms. Another year has to pass before we have more accurate knowledge of the behavior of this disease,” says the expert.

The health authorities aim to have all Mexicans vaccinated by March 2022. According to González, if this were to be achieved, the population would reach at least 70% immunity, which would mean an almost undetectable transmission of the virus.

“In the first six months of 2022, it’ll be clearer if Covid-19 behaves seasonally or not,” he concludes.