The Covid Virus Keeps Evolving. Why Haven't Vaccines?

The first volunteer to receive a shot of Moderna's Covid-19 vaccine was on March 16, 2020. Pfizer's Covid vaccine would be approved for use in the US less than a year later, a record-breaking achievement. It took about four years to develop a vaccine for mumps.

Both companies were able to deliver their vaccines in a short period of time. Scientists use a piece of genetic code called mRNA instead of the virus to spur an immune response. The body is told to make a version of the coronaviruses spikeProtein so that it can make antibodies to it. The immune system is prepared to launch an attack if it encounters the same thing again.

The promise of the technology was it's ability to adapt. The nature of the vaccine is plug and play. Scientists could swap in a new piece of mRNA to match the new version of the virus if it became resistant to vaccines. The Covid-19 vaccine and booster shots still target the original virus that was identified in late 2019. Why have variant-specific boosters yet to arrive?

You are working with a fast changing virus. The dean of the Chicago Medical School says that each variant is around for a few months and is replaced by a new one. There is a race that we are constantly behind on. Chatterjee is a member of the Vaccines and Related Biological Products Advisory Committee and advises the US Food and Drug Administration.

Peter Marks, director of the FDA's Center for Biologics Evaluation and Research, said during a June 28 meeting that the effectiveness of the current vaccines has waned with time. The initial booster shots helped restore some protection against severe disease.

In June, all of these factors led to the recommendation that vaccine manufacturers update Covid booster shots for fall and winter 2022. Evidence shows that these subvariants are driving a new wave of hospitalizations in the US and the UK. The US government plans to buy a lot of variant-specific doses.