Covid variants will be the next big challenge. Can vaccines protect us? - The Guardian

The virus that causes Covid-19 is no different: it has moved from the animal realm, where it most likely originated in bats, to the human world.

We now have the vaccines to protect us against Covid-19 – but what happens when this virus mutates further, as it likely will.

Some vaccines show promising signs of coping with new variants – the mRNA vaccines manufactured by Pfizer and Moderna seem to offer some protection against the variants first identified in Kent and South Africa.

Most virologists think that Covid-19 vaccines will protect against severe disease and death, even in people who have been infected by a mutated strain of the virus.

Moreover, some vaccines may offer little or no protection against people becoming infected by a Covid-19 variant and passing this on to others (but experts believe that vaccines, together with a host’s natural immune response, should still offer enough residual protection to prevent severe disease and death).

The virus that causes Covid-19 can produce new variants in at least two different ways.

Firstly, the virus can undergo recombination, which is what happens when different pieces of genes from different viruses infect the same cell and mix to produce new variants.

Secondly, the virus can infect one immunocompromised patient for a long time, and then evolve within that patient to produce a new variant.

And there are already plans in place to update the Pfizer, Moderna and AstraZeneca vaccines to match the South African variant more closely.