Lots of questions coming in about this.
COVID19 antibodies are acting as we predicted…they are lasting long. In the beginning of the pandemic, we hypothesized that they would last 1-2 years like its cousins (SARS and MERS). So far, COVID19 is on track with this timeline.
Until now, studies have shown that COVID19 antibodies last 3 months. But that’s because these studies were only 3 months long. We were (and are) at the mercy of time.
Now that more time has passed, longer studies are coming out. Recently, three separate publications have shown COVID19 antibodies last 120 days, 155 days, and 240 days (8 months). In other words, the majority of people that recover from COVID19 have enough immune cells to fight the virus and prevent illness for at least 8 months. Again, these studies were only 120, 155, and 240 days long, respectfully. Antibodies likely last even longer.
The antibodies have a slow rate of decline. Two important points regarding this…
- You shouldn’t worry about waning COVID19 antibodies. This is normal a normal sign of a healthy immune response. It doesn’t mean these people are no longer protected. Antibodies only represent one part of the immune response; it’s not the full picture.
- The slow decline suggests that the antibodies could last a very long time. This wouldn’t, necessarily, be surprising because we know that SARS (COVID19’s cousin) immune cells can last up to 17 years after recovery.
Frequency of Vaccines. Once we have a better picture of how long antibodies last, we can determine how often we will need a vaccine. This has yet to be determined.
Mutations. There have been COVID19 mutations. However, these mutations haven’t changed the virus enough to impact a vaccine effectiveness. We are keeping a close eye on this, though, as this is always a possibility with a virus. This is why a lot of scientists were/are paying attention to the mink mutation in Denmark.
“Long term” antibody studies: https://pubmed.ncbi.nlm.nih.gov/33033172/ (122 days), https://pubmed.ncbi.nlm.nih.gov/33033173/ (115 days), https://www.biorxiv.org/content/10.1101/2020.11.15.383323v1 (8 months)
3-month antibody studies: https://yourlocalepidemiologist.com/how-long-do-antibodies-last/