> how do you reconcile your position with [1]?

The CDC publication you cited has a relatively small sample size (N=738) and uses data from a single state during a 2-month period. The confidence interval on the "2.34" odds ratio is large (95% CI = 1.58–3.47). Most importantly, a tremendous amount of literature has contradicted their findings.

Multiple large scale and long term serological studies have demonstrated that immunity acquired through previous infection has been at least equally durable and effective as vaccination in preventing reinfection.

- 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. [1] (N=25,661)

- In conclusion, documented SARS-CoV-2 reinfections were exceedingly rare, with an incidence of 0.3 infections for every 1000 persons-week, and none were severe. Seroconversion after symptomatic or asymptomatic SARS-CoV-2 infection seems to be associated with a 10-fold reduction in risk of successive viral infection contamination, lasting at least 8 months. [2] (N=1,494)

- The study results suggest that reinfections are rare events and patients who have recovered from COVID-19 have a lower risk of reinfection. Natural immunity to SARS-CoV-2 appears to confer a protective effect for at least a year, which is similar to the protection reported in recent vaccine studies. [3] (N=15,075)

- Reinfection is rare in the young and international population of Qatar. Natural infection appears to elicit strong protection against reinfection with an efficacy ~95% for at least seven months. [4] (N=192,967)

- The degree of protection (10-fold) associated with seropositivity appears to be comparable to that observed in the initial reports of the efficacy of mRNA vaccines in large clinical trials. [5] (N=3,257,478)

> One huge reason the CDC kept telling people to get vaccinated was to reduce transmission rates

It's important to note that transmission is also equally well reduced by immunity acquired through natural infection.

> It's not just about your personal health here. Yet people didn't listen, and now we have a strain whose transmission appears to be far less affected by vaccination.

You seem to be implying that if everyone had been vaccinated the virus wouldn't have mutated into a variant with increased transmission/virulence. That fact is that the current vaccines do not provide sterilizing immunity. Therefore transmission, mutation, and selective pressure would have continued at a rate that would still be extremely likely to evolve into VOCs [6]. Moreover, analogous to antibiotic resistance, evolution of vaccine resistance is a non-trivial risk associated with mass vaccination strategies [7][8]. This brings us back to OP which is strong evidence suggesting that natural infection may induce an immune response that is more robust to variants of concern such as delta.

Considering all of these facts, the optimal public health strategy will likely involve a mix of vaccination, naturally acquired immunity, and other viral elimination strategies such as early treatment using multi-drug therapies based on existing and widely available medications which have been proven to be effective at reducing hospitalization and death [9][10][11][12][13][14].

[1] SARS-CoV-2 infection rates of antibody-positive compared with antibody-negative health-care workers in England: a large, multicentre, prospective cohort study (SIREN)
https://pubmed.ncbi.nlm.nih.gov/33844963/

[2] Risk of Reinfection After Seroconversion to Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2): A Population-based Propensity-score Matched Cohort Study
https://academic.oup.com/cid/advance-article/doi/10.1093/cid...

[3] Assessment of SARS-CoV-2 Reinfection 1 Year After Primary Infection in a Population in Lombardy, Italy
https://jamanetwork.com/journals/jamainternalmedicine/fullar...

[4] SARS-CoV-2 antibody-positivity protects against reinfection for at least seven months with 95% efficacy
https://www.sciencedirect.com/science/article/pii/S258953702...

[5] Association of SARS-CoV-2 Seropositive Antibody Test With Risk of Future Infection
https://jamanetwork.com/journals/jamainternalmedicine/fullar...

[6] The total number and mass of SARS-CoV-2 virions
https://www.pnas.org/content/118/25/e2024815118

[7] Risk of rapid evolutionary escape from biomedical interventions targeting SARS-CoV-2 spike protein
https://pubmed.ncbi.nlm.nih.gov/33909660/

[8] Can we predict the limits of SARS-CoV-2 variants and their phenotypic consequences?
https://www.gov.uk/government/publications/long-term-evoluti...

[9] Multifaceted highly targeted sequential multidrug treatment of early ambulatory high-risk SARS-CoV-2 infection (COVID-19)
https://scholarlycommons.henryford.com/cgi/viewcontent.cgi?a...

[10] Timing of Antiviral Treatment Initiation is Critical to Reduce SARS-CoV-2 Viral Load
https://ascpt.onlinelibrary.wiley.com/doi/pdf/10.1002/psp4.1...

[11] Clinical outcomes after early ambulatory multidrug therapy for high-risk SARS-CoV-2 (COVID-19) infection
https://rcm.imrpress.com/EN/article/downloadArticleFile.do?a...

[12] Early multidrug treatment of SARS-CoV-2 infection (COVID-19) and reduced mortality among nursing home (or outpatient/ambulatory) residents
https://www.sciencedirect.com/science/article/abs/pii/S03069...

[13] Ivermectin in combination with doxycycline for treating COVID-19 symptoms: a randomized trial
https://pubmed.ncbi.nlm.nih.gov/33983065/

[14] Fluvoxamine: A Review of Its Mechanism of Action and Its Role in COVID-19
https://www.frontiersin.org/articles/10.3389/fphar.2021.6526...