Based on my research, if you have been infected with COVID-19, there is no good reason for you to get vaccinated. Getting Covid provides you with a natural immunity to future reinfections that is thousands of times more effective than the immunity conferred by the vaccines. Also, the vaccines fare no better than natural immunity at preventing the transmission of Covid. Let me explain.

Personal protection

Studies have shown that those who become infected with Covid develop a natural immunity that lasts for at least 7-8 months, and most likely, years to come. The National Institutes of Health (NIH) funded a study that was published January 6, 2021 in Science.[1] Speaking of this study, the NIH writes: “But, promisingly, their levels [of antibodies] remained fairly stable over time, declining only modestly at 6 to 8 months after infection. …. 95% of the people had at least 3 out of 5 immune-system components that could recognize SARS-CoV-2 up to 8 months after infection.”[2] A decline in antibodies does not mean that immunity is diminishing rapidly over time. Immunologist Scott Hensley, of the University of Pennsylvania, notes that “[i]t doesn’t mean that those people no longer have antibodies. It doesn’t mean that they don’t have protection.”[3]

A British study published in The Lancet found that “a previous history of SARS-CoV-2 infection was associated with an 84% lower risk of infection, with median protective effect observed 7 months following primary infection. This time period is the minimum probable effect because seroconversions were not included. This study shows that previous infection with SARS-CoV-2 induces effective immunity to future infections in most individuals.”[4] And again: “After 7 months of follow-up, this large observational study showed that previous SARS-CoV-2 infection protects most individuals against reinfection for an average of 7 months. We have identified and investigated more potential reinfections than reported in the global literature to date…. This study supports the hypothesis that primary infection with SARS-CoV-2 provides a high degree of immunity to repeat infection in the short to medium term; with similar levels of prevention of symptomatic infection as the new licenced vaccines for working-age adults.”[5] In other words, natural immunity is comparable to vaccine-induced immunity. As I’ll discuss later, this is an understatement. Natural immunity is way more effective than vaccine-induced immunity.

While both studies could only show natural immunity for 7-8 months, this doesn’t mean natural immunity only lasts for 7-8 months. This timeframe is only a reflection of how much time had passed since the participants in the studies had recovered from Covid. One of the authors of The Lancet study, Shane Crotty, specifically noted that the “amount of [immune] memory would likely prevent the vast majority of people from getting hospitalized disease, severe disease, for many years.”[6] Ecologist John Drake, of the University of Georgia, estimates that natural immunity could last as long as 4.7 – 8.4 years based on The Lancet study’s data.[7] Last year, researchers found that those infected by the original SARS-CoV virus still have a natural immunity 17 years later.[8]

Do the vaccines provide a longer immunity against Covid? No one knows for sure[9], in part, because the vaccines are so new, and because the vaccines are not 100% effective at preventing infection. We know that ~10% of those who get vaccinated will still contract the virus (and that number is likely to increase as time elapses).[10] When a vaccinated person gets infected, it would be difficult to determine if they did so because they were part of the 5-6% for whom the vaccines fail, or if they got infected because the vaccine-induced immunity against Covid had worn out. All we know at this point is that the antibodies created from the Pfizer vaccine are still robust after six months.[11] As of now, we have no reason to believe that vaccine-induced immunity will last any longer than naturally occurring, virus-induced immunity.

Social transmission

Until now, I have focused on comparing the effectiveness of natural immunity and vaccine-induced immunity for preventing one from personally contracting Covid in the future. But some might wonder if the vaccine is more effective than natural immunity at preventing the transmission of Covid to someone else? Could an immunized person A encounter infected person B, not contract Covid from B, and yet transmit B’s Covid to healthy person C? No. There is no evidence to support the idea that Covid can be transmitted from a sick person to a healthy person via an intermediary. Covid is only transmitted directly from an infected person to a healthy person. A person with a natural immunity to Covid could only transmit Covid to others if he was personally reinfected with Covid.

How likely is that? Very unlikely. According to the CDC, “[c]ases of reinfection of COVID-19 have been reported but are rare.” The precise number of reinfections is hard to pin down for a variety of reasons[12], but there are only 72 confirmed cases in the world according to one tracker (and 44 more from an English study[13]), and at best, 40,000 additional suspected cases.[14] Compare this to the number of infections that will be experienced by the vaccinated. If ~10% of the vaccinated will still contract Covid, this means millions of vaccinated will still get Covid. Approximately 355 million people have been fully vaccinated worldwide as of May 17.[15] Statistically speaking, ~35,000,000 of them will contract Covid. That’s tens of thousands compared to tens of millions.[16] Clearly, one is much safer being around those with a natural immunity to Covid than those with a vaccine-induced immunity.

Natural immunity offers more protection against Covid than virus-induced immunity

This also shows why natural immunity confers more protection against Covid than the vaccines. Approximately 161,000,000 people across the globe have contracted Covid and survived. If a maximum of 40,000 got reinfected with Covid, that would mean natural immunity failed to prevent future Covid infections just 0.025% of the time. Compare this to vaccines which fail to prevent Covid .0.037% – 0.078% of the time.[17] That means natural immunity is at least 1.4x – 3x better at preventing a future Covid infection than vaccines. Given the fact that we only know of 116 confirmed cases of reinfection, natural immunity is even stronger. Even if we generously inflate this number up to 500, this would give us a reinfection rate of just 0.00031%. That’s 119x – 252x better at preventing a future Covid infection than vaccines. Even if the Covid vaccines end up being more effective than the trials indicated, they will still pale in comparison to natural immunity.

If you want to follow the science, there is no reason to think those who have already been infected with Covid need to get a Covid vaccine. And given the fact that more than 1/3 of Americans have gotten Covid, that means more than 1/3 of Americans are already immune to getting reinfected with Covid in the future.[18]

 

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[1]https://pubmed.ncbi.nlm.nih.gov/33408181/

[2]https://www.nih.gov/news-events/nih-research-matters/lasting-immunity-found-after-recovery-covid-19

[3]https://www.nytimes.com/2020/10/27/health/coronavirus-antibodies-studies.html

[4]https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(21)00675-9/fulltext

[5]https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(21)00675-9/fulltext

[6]https://www.nytimes.com/2020/11/17/health/coronavirus-immunity.html

[7]https://www.forbes.com/sites/johndrake/2021/04/15/how-long-does-immunity-to-sars-cov-2-last/?sh=66e63dc2f376

[8]https://www.nature.com/articles/s41586-020-2550-z

[9]https://www.wsj.com/articles/how-long-do-covid-19-vaccines-provide-immunity-11618258094

[10]https://www.healthline.com/health-news/pfizer-and-moderna-covid-19-vaccines-are-90-effective-in-real-world-setting

[11]https://www.wsj.com/articles/pfizer-biontech-covid-19-vaccine-protects-for-six-months-companies-say-11617273901?mod=article_inline

[12]https://www.statnews.com/2021/04/07/covid-19-reinfections-still-seem-rare/

[13]https://www.medrxiv.org/content/10.1101/2021.01.13.21249642v1

[14]https://bnonews.com/index.php/2020/08/covid-19-reinfection-tracker/

[15]https://ourworldindata.org/covid-vaccinations?country=OWID_WRL

[16]There is evidence to suggest that when people are reinfected, the symptoms are less severe than the first time.

[17]Based on the Moderna phase 3 trial data. While the vaccine efficacy was shown to be 94.1%, that doesn’t mean 6 out of every 100 people get Covid. Rather, it means vaccinated people are 94% less likely to get Covid than unvaccinated people. For example, if unvaccinated people had a 50% chance of getting Covid, a person with the Moderna vaccine would only have a ~3% chance of getting Covid. Out of 14,134 people in the Moderna trial who received the vaccine, only 11 got Covid, which is 0.078% of the population. See https://www.modernatx.com/covid19vaccine-eua/providers/clinical-trial-data. The Pfizer vaccine was found to be 95% effective in phase three trials. Only eight of the 21,720 vaccinated persons got Covid (0.037%). See https://www.pfizer.com/news/press-release/press-release-detail/pfizer-and-biontech-announce-publication-results-landmark.

[18]See the CDC’s estimates at https://www.cdc.gov/coronavirus/2019-ncov/cases-updates/burden.html. As of June 16, 2021, the webpage indicates that there have been 114.6 million Americans infected between February 2020 and March 2021.