How would COVID-19 vaccine makers adapt to variants?
How would COVID-19 vaccine makers adapt to variants?
By tweaking their vaccines, a process
that should be easier than coming up with the original shots.
Viruses constantly mutate as they
spread, and most changes aren’t significant. First-generation COVID-19 vaccines
appear to be working against today’s variants, but makers already are taking
steps to update their recipes if health authorities decide that’s needed.
COVID-19 vaccines by Pfizer and
Moderna are made with new technology that’s easy to update. The so-called mRNA
vaccines use a piece of genetic code for the spike protein that coats the
coronavirus, so your immune system can learn to recognize and fight the real
thing.
If a variant with a mutated spike
protein crops up that the original vaccine can’t recognise, companies would
swap out that piece of genetic code for a better match — if and when regulators
decide that’s necessary.
Updating other COVID-19 vaccines
could be more complex. The AstraZeneca vaccine, for example, uses a harmless
version of a cold virus to carry that spike protein gene into the body. An
update would require growing cold viruses with the updated spike gene.
The Food and Drug Administration said
studies of updated COVID-19 vaccines won’t have to be as large or long as for
the first generation of shots. Instead, a few hundred volunteers could receive
experimental doses of a revamped vaccine and have their blood checked for signs
it revved up the immune system as well as the original vaccines.
More difficult is deciding if the
virus has morphed enough to modify shots.
Globally, health authorities will
monitor coronavirus mutations to spot vaccine-resistant mutations. They’d also
have to decide whether any revamped vaccine should protect against more than
one variant.
Overall the process would be similar to what already happens with flu vaccine. Influenza viruses mutate much faster than coronaviruses, so flu shots are adjusted every year and must protect against multiple strains.
–AP