Question

Covid-19 is often said to merely be another type of flu, at least symptomatically. However, it is a fundamentally different virus, being +sense instead of -sense RNA. Practically speaking, the mutation rate for SAR-CoV-2 is much lower than that of the influenza virus. What consequence might that have for vaccination development? (More than one answer possible)

A. Influenza strains may mutate sufficiently so that the vaccine doesn't work on all strains in a given year.

B. We have to develop new vaccines for influenza every year, whereas we may not have to do so for SARS-CoV-2.

C. If we are able to develop a SAR-CoV-2 vaccine, it will likely be useful against most strains.

Answer 1

B. We may not have to do for SARS-CoV-2. Because the mutation rate is low. And the virus has proofreading machinery which can low the error rate and also reduces mutation.

A. Vaccine doesn't work on all strains because mutation rate is so high, changes in the gene leads to the changes in surface proteins. Which is known as antigenic drift. Per year it varies the effectiveness between the influenza A and B. Generally vaccine is more effective against influenza A virus. In 2019 the effectiveness was 40-60%.