Get Ready to Play 'Guess the Viral Variant'

The year of Covid lockdowns was 2020 and the year of vaccines was 2021. The year of variant prediction will be in 2020. The picture of where the Pandemic would go next was muddied by the first Covid variant that was identified. Alpha was better at transmitting thanBeta was better at evading immunity What is the long-term pattern of evolution?

Large epidemics were caused by the Omicron BA.1 variant. A new subvariant, BA.2, emerged against which the immunity was less effective. The cycle started again after large epidemics, with another cycle in mid-twentieth century.

We will see this pattern in the years to come. The seasonal coronaviruses have been causing epidemics for a long time. coronaviruses gradually evolve over time so prior immunity is less effective.

The challenge for the Covid-19 vaccine campaigns will be created if the viruses evolve in this way. Updating vaccines can take a while. The World Health Organization makes recommendations twice a year about which strains of flu should be included in the vaccine. When it comes to winter vaccines, decisions are made more than six months in advance. Predicting vaccine selection is a challenge.

Teams use a range of data, from the growth rates of circulating variant in genomic data to tests of their immunological properties when selecting a vaccine for the flu. Variation in what different populations have been exposed to is another problem. Variants that can evade immunity have an advantage over others. Different flu viruses can be seen in different parts of the world.

This prediction challenge will become a regular one for Covid in the future. The Omicron BA.1 subvariant has been adapted by some countries. Will the new vaccines match the variant that circulates further down the line? The decisions for winter in the northern hemisphere will have to be made early in the future. Future Covid waves could be affected by getting the choice right. The H3N2 flu subtype, which tends to cause the largest seasonal epidemics, has a less than 50% effectiveness against symptoms.

There is hope for a vaccine that will work against a wide range of coronaviruses. The history of development for other universal vaccines shows that success is not always assured. The coming year will be the beginning of a long game of cat and mouse, pitting vaccine updates against an evolving virus. One of the major health challenges of the next decade will be the roll out of vaccines.