It’s a long and complicated answer, but here is the gist of it. We know that an individual’s immune response to a virus varies from person to person. As a general rule (there are exceptions), people with mild illness generally mount a weaker immune response than people with more https://twitter.com/bigbaldbaby/status/1358453209157652481

severe disease. Older individuals tend to mount a weaker immune response than younger. Now on to COVID. There is also a varied strength of immune response to natural infection. Some people appear to be immune for only a couple to several months; others appear to have immunity for

6-8 months. With natural infection, the body is responding to a large range of targets on the virus and mounts an immune response that is very broad, and the majority of the antibodies produced don’t actually “neutralize” the virus. Plus, with natural infection, the virus gets a

week’s head start because it takes that long for your body to develop the antibodies. With the vaccine, we can focus the body’s immune response to make a much higher percentage of the “neutralizing” antibodies by selecting a selected piece of the virus for the body to respond to,

rather than the entire virus. In this case, the spike protein. Further, vaccination prepares the body with the memory of how to ramp up production of these antibodies in the event they are ever exposed to the virus, rather than waiting 7-10 days for the body to make them from

scratch. Plus, with vaccines, we can give the first dose to ramp up the humoral immune response (antibodies) and a second shot to ramp up the cellular immune response (which is what will make the immunity much more longer lasting). Plus, some vaccines include adjuvants (those

will be in some of the next vaccines) that can further ramp up the immune response. With natural infection, you have some immunity against the strains you were infected with. However, the evidence out of Brazil suggests you have little, if any, protection against the variants.

The current vaccines do provide some protection against the variants and we have the ability to modify the vaccine in a reasonably short period of time to adjust if we discover that we need more protection. But, nothing we can do to enhance the immunity against variants in those

with natural infection other than vaccine.