Reading the following article, despite what author tries to tell us, seems to me it doesn't show that breakthrough 2nd infections after natural immunity are more common than breakthrough 1st infections after vaccination.
Also, natural immunity may not last as long as vaccine induced immunity from a 2-dose vaccine. But they may last longer than from a 1-dose vaccine. A second dose after infection (either re-infection or vaccination) may provide more protection than does "the best vaccine". I think we've seen reports showing very high protection from one dose of mRNA after recovery from Covid.
"There are provinces in
Iran where it seems there have been more
COVID cases than there are people. In other words, it’s possible that in some of the worst-hit regions, a whole lot of people caught COVID
twice.
That’s not just bad news for Iran’s 84 million people. It’s also bad news for, say, the 3 million people in
Mississippi and the 5 million in
Alabama. Experts believe Iran is vulnerable to reinfection because it’s under-vaccinated and has relied too much on fragile natural antibodies from past infection to protect people."
"It’s increasingly clear that the natural antibodies resulting from past infection by SARS-CoV-2 fade after around six months. The best vaccines, by contrast, hold up much longer."
Andi Rice/Bloomberg via GettyThere are provinces in Iran where it seems there have been more COVID cases than there are people. In other words, it’s possible that in some of the worst-hit regions, a whole lot of people caught COVID twice.That’s not just bad news for Iran’s 84 million people...
news.yahoo.com
That report didn't say how high about 100% of population was the total infection count. If total was 200%, could easily say natural immunity showed no effectivness.
The following shows 0.25% reinfection of a group over 9 months. Doesn't provide infection rate for a "covid naïve" cohort, but if infection of the unvaccinated was 10% of population during that period, would seem natural immunity was 97.5% effective.
"our aim in this study was to evaluate the rate of re-infection over a 9-month period after the onset of COVID-19 epidemic in Shahroud, a city located in northeastern Iran."
Considering how the pandemic has peaked and then fallen to low levels over later months, "10%" may not be a good estimate of infection rate for non-identified control group
It doesn't qualify as a double-blind study:
"On the other hand, in our study, 30% of re-infection cases were from the medical staff who were constantly exposed to the virus and this could be a reason for re-infection. In contrast, re-infection in other patients can be reduced due to adhering safety protocols and the fear created by the previous encounter."
COVID-19 re-infection in Shahroud, Iran: a follow-up study - Volume 149
www.cambridge.org
The "article" said natural herd immunity doesn't work, but this research paper said it does:
"According to the findings of this study, relative immunity develops following COVID-19 infection, nevertheless there is a small possibility of re-infection in people recovering from COVID-19"