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Q&A – How Long Does Natural Immunity From COVID-19 Last?
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Today’s entry: Hey Brian- I was really interested to hear that the legislature is going to take up natural immunity. Finally! What I still haven’t heard is how long natural immunity from Covid lasts. Because we’re not hearing about a bunch of reinfections I’d guess it IS proving to be more effective than the vaccines.
Bottom Line: Your assumption is looking pretty accurate. Before digging into your question here’s a quick reset for those who might not be familiar with what we’re talking about. In Florida’s special state session which kicks off next week, they’ll consider at least four bills which would address numerous considerations related to the pandemic. One of the bills, as currently written, would grant consideration for those who’ve recovered from COVID-19 and thus have natural immunity to the virus. Should this happen Florida would be the first state to legally view natural immunity as being at least on par with COVID-19 vaccinations. The excerpt from the bill as currently written states this:
- To claim an exemption based on COVID-19 immunity, the employee must present to the employer an exemption statement demonstrating competent medical evidence that the employee has immunity to COVID-19, documented by the results of a valid laboratory test performed on the employee. The Department of Health shall adopt a standard for demonstrating competent medical evidence of such immunity.
The exemption referenced is regarding any employer or organization which would require proof of a COVID-19 vaccination in Florida. As stated, anyone who has recovered from COVID-19 would be able to use the results of a “lab test” in lieu of providing proof of vaccination. So now about your question, what’s the durability of natural immunity? The CDC’s current official line on reinfections is this: Cases of reinfection with COVID-19 have been reported, but remain rare. That stands in contrast to their official line regarding breakthrough cases from those who’ve been vaccinated against COVID-19: Vaccine breakthrough infections are expected. COVID-19 vaccines are effective at preventing most infections. However, like other vaccines, they are not 100% effective. The contrast from the CDC’s characterization of reinfections being rare, as opposed to breakthrough cases being expected, says about as much as can be said without the CDC providing updated numbers for both categories which, for whatever reason, they’re currently not.
Prior to the advent of the delta variants, a study published in the medical journal The Lancet, showed reinfection rates one year later for those who’d contracted COVID-19 was0.65%. Meaning antibodies one year later appeared to have greater than 99% efficacy in prevention from reinfection. Both the duration and overall efficacy showed that in fact, at least prior to the variants, natural immunity was superior to any of the available vaccines. That data certainly supports the validity of Florida’s state legislature considering natural immunity equitably with vaccinations. But about your question regarding the durability of natural immunity. Just last month there was a new study in The Lancet addressing natural immunity.
In the study entitled The durability of immunity against reinfection by SARS-CoV-2 researchers found natural immunity could last for as few as three months and as many as61 months, or longer than five years. While we obviously haven’t come close to being five years into this pandemic (and hopefully never will) they were able to model currently available data to project the long end of the curve. What it all comes down to is the individual and the strain as to if one’s at the early end of the curve or the long end. Across all models the average duration of efficacy for natural immunity in combating COVID-19 was 16 months.
So yes, in all available research natural immunity has proven to be more effective and longer lasting - though like the vaccines, the duration of efficacy specific to you is little more than a guessing game. Regardless, the state is on solid ground should they legitimize natural immunity in the upcoming special session which appears likely to happen. I’ll keep you posted. The next few weeks will likely be the most defining yet with the Biden administration's employee vaccine mandate to be decided in the courts and the state of Florida set to enact related policies. I’ll keep you posted.