What have the last nine months taught us about the virus itself and how can we best protect ourselves and our communities?
The coronavirus that causes COVID-19, SARS-CoV-2, is a novel virus. We have never seen it before. Even though we’ve been in this pandemic for nine months, there are still many unknowns. Because of this, we cannot draw any long-term conclusions about immunity. We can’t even draw long-term conclusions about the recovery.
Restoration: We don’t know how this disease will affect in the long term. And that’s one of the most confusing and scary factors in this pandemic. This is the only way we can determine what it looks like to be a fully recovered COVID-19 patient and whether there are residual effects.
Mutations: We know the virus mutates very slowly. It doesn’t change much. That’s a good thing: Potential vaccines are not outperformed by any viral mutation. Mutations got a bad rap for getting those Hollywood pictures of things going completely out of control. In reality, mutations are an incredibly normal and expected process in virus replication. A good way to think about mutations in viruses is that they are like typos: often you type quickly, and a typo changes the spelling of a word a little, but the meaning of the sentence doesn’t change dramatically. The same is true of a virus: a slight mutation during replication does not necessarily mean that the virus is changing in a meaningful way.
“Aside from public health efforts, we need a vaccine to prevent infection.”
Immunity and Reinfection: Based on the data we have, we can assume that it is fairly unlikely that someone will be re-infected with the virus within ninety days of being first infected, but we have seen cases of re-infection. They are very rare, but re-infection is not impossible. The reason it isn’t impossible is that there is no blanket post-infection situation. Not every immune response is the same. Some people may not develop long-lasting antibodies and are in a position of vulnerability. Some people may develop some antibodies and still get infected again. Antibodies aren’t the only way to measure an immune response. We also need to consider T cell and B cell responses, which can vary.
Here’s how it differs from vaccination: Vaccines tend to produce robust long-term immune responses. Herd immunity can only be established through vaccination. It is totally inappropriate to use the term “herd immunity” outside of a vaccination campaign.