COVID-19 Immunity: Catching a Disease to Prevent a Disease?

Kevin Kavanagh, MD

I had to stop and read the Seattle Times news article "UW study: Catching COVID gives protection from its worst effects." The title appears to advocate catching a dangerous virus so you will not have to worry about future complications if you recover without death, hospitalization, or long COVID. This is a dangerous interpretation; one does not catch a disease to avoid a disease. The article’s first sentence states: "A past COVID-19 infection offers ‘durable,’ temporary protection against getting severely sick with the coronavirus." Can you please tell me what 'durable - temporary protection' is? How can something be durable but only temporary, lasting for 10 months?
 
The study reported that pooled data found the protection of an ancestral strain infection against Omicron BA.1 reinfection was 78% against hospitalization but only 45.3% against reinfection. At 40 weeks, the protection against BA.1 reinfection dropped to 36.1%. This protection would be expected to be even less effective with the highly immune-invasive XBB.1.5 and BQ.1.1 variants currently comprising 80.2% and 12.1% of the isolates in the United States, respectively.
 

Sweden: Number of Deaths per Million Population

(Courtesy of author)

Today, COVID-19 infections may give comparable or stronger immunity than the original 2-dose vaccine. But do not celebrate; this is a self-fulfilling prophecy. Pre-Delta vaccination had a definite edge. However, early in the pandemic, it was warned that the virus would spread and mutate if the public did not widely embrace public health measures, eventually making the vaccine ineffective. The FDA and CDC acknowledge that the old monovalent vaccine does not adequately cover current variants. This is why it is so important to receive the new bivalent booster.
 
Avoidance of hospitalizations is an important goal. But even mild infections often lead to long COVID with its mental, cardiac, and immunological consequences. The presentation of these sequelae can be delayed, resulting in long-term disability and almost doubling the total deaths in the post-acute period (excess deaths of 0.84% in the post-acute period).
 
Since the beginning of the pandemic, some researchers have advocated the enhancement of natural immunity through infection. Fringe elements often refer to Sweden as the poster child for this approach. However, the results from Sweden have been discouraging. The country has also come under fire for significant delay and underreporting of data during the first year of the pandemic. What is agreed upon is that Sweden implemented few mandates, and there was minimal masking in the public sector. The country is extensive and sparsely populated, which will help inhibit the spread of disease, but compared to its Nordic neighbors of Finland and Norway, Sweden has far more COVID-19 deaths. (1595, 928, 2310 per million, respectively).
 
Herd immunity was not achieved in Sweden. According to Sweden's State Epidemiologist, Anders Tegnell, during the surge in the Spring of 2021, the COVID-19 case incidence rate reached 454 cases per 100,000, a “very high figure.” In one region, the incidence rate reached 981. Sweden recently had another surge in deaths in the Winter of 2022/23. During this surge, there was an overall case fatality rate of 0.87%, similar to that of other nations.
 Economically, in 2023 Sweden is forecasted to undergo the worst economic downturn in the European Union and is the only country predicted to experience shrinkage rather than growth.
 
Sweden also has had 2 vast surges of the respiratory syncytial virus, which because of the country’s lack of implementing stringent COVID-19 strategies, supports the existence of post-COVID-19 immune hypofunction. Like other countries, acute COVID-19 may have damaged Immunological defenses. In addition, as reported in other nations, a percentage of the population would also be expected to develop long-term cardiac damage and central nervous system damage."
 
SARS-CoV-2 is a dangerous virus. Senator Rand Paul stated on February 9, 2023, during a United States Foreign Relations Committee Hearing, that 1 million Americans have died of COVID-19 and that an estimated 5 to 18 million have died worldwide. One cannot argue that SARS-CoV-2 is an enhanced gain-of-function modified virus, but no one asserts it is not a grave threat.
 
Unfortunately, neither vaccination nor infection provides durable protection. Hybrid immunity is best, but becoming infected to achieve immunity is a perilous strategy.

At the most recent FDA Vaccines and Related Biological Products Advisory Committee meeting, the topic of COVID-19 infections being similar to vaccinations was proposed for future consideration. This could allow a single booster or vaccine dose to follow an acute infection. Regardless of the final decision, there is a minimal downside to boosting your immunity to help avoid long COVID. Our goal as a nation must not be to become reinfected yearly; this is not a viable option.