Can infection with the new crown be more protective than vaccination?

*For medical professionals to read for reference, how strong is the immune protection after being infected with the new coronavirus? Written | Source of Ling Jun | "Medical Community" Public Account On April 20, a real-world study published by researchers at the University of Chicago in the "JAMA Network Open" (JAMA Network Open) showed that pre-existing symptoms SARS-CoV-2 infection provided comparable levels of protection to mRNA vaccination, while the duration of protection was even longer than mRNA vaccination
.

The study included data on patients tested for COVID-19 at 1,300 medical facilities in 6 U.
S.
states and followed more than 120,000 participants for up to nearly 8 months.
It is one of the largest real-world studies of its kind.
one
.

The study was conducted between October 1, 2020 and November 21, 2021
.

Of the 121,615 unvaccinated trial participants, 24,043 had been infected with COVID-19 before enrollment, with a median follow-up of about half a year
.

The results showed that during the entire study period, 98 of the 24,043 people who were originally infected with the new crown were re-infected
.

Of the 97,572 people in the control group, 2,762 were infected with the new coronavirus
.

After adjusting the age, gender, race and other factors of the two groups of subjects through the analysis model, the researchers calculated a set of exact protection data: the protection rate of previous infection with the new crown against secondary infection was 85%, The protection rate for moderate and severe cases of secondary infection was 88%
.

This is almost the same as the relevant protection data published by mRNA vaccines before.
It is worth mentioning that the researchers found that the period of immune protection obtained by natural infection seems to be longer
.

The protection level has remained stable in the past 8 months
.

As a comparison of the immune protection provided by natural infection over time, a large number of previous studies have shown that 6 months after the whole process of new crown vaccination, the protection of vaccines with different technical routes has decreased to varying degrees
.

Such results provide new insights into the duration of protection after initial infection in the unvaccinated population and could have important implications for vaccination guidelines and public health policy, the researchers said
.

Non-negligible innate immunity This is not the first study to compare the level of protection from new crown infection and vaccination
.

Previously, a series of laboratory studies showed that for different types of new crown mutants, vaccinated people produced much higher titers of neutralizing antibodies than unvaccinated people who had been infected with the new crown
.

Based on such data, the conclusion seems to be that vaccination provides much greater protection than natural infection
.

But this does not seem to be the case in the real world: In March 2021, Danish researchers conducted an observational study of about half a million inhabitants of the country and calculated that, after adjusting for variables, infection with the new crown provided about 80.
5% of the Protection against reinfection
.

Another retrospective study conducted in Israel in August of the same year found that compared with people who received a dose of mRNA vaccine, patients infected with the new crown during the same period but not vaccinated had a lower risk of subsequent infection with the delta strain by 13% times
.

Why do lab data contradict real-world conditions? Lu Mengji, a German-Chinese virologist and professor at the Institute of Virology at Essen University School of Medicine, told the "medical community" that such real-world results are expected
.

"Based on a series of reasons such as experimental conditions and costs, the research carried out by most laboratories around the world is mainly aimed at the neutralizing antibody titers generated after acquired immunization
.

" Lu Mengji said, "Therefore, a cognitive misunderstanding has arisen, that is, 'Neutralizing antibody titer' is the gold standard for assessing 'COVID-19 protection'
.

"Inoculation of the new crown virus can activate humoral and cellular immunity to varying degrees.
In addition, the human body has natural immunity, that is, non-specific immunity.
The initial new coronavirus infection can activate this system and provide protection against secondary infection, but related research But less
.

"Israeli scholars also mentioned in the above-mentioned study in August 2020 that compared with the "anti-spike protein immunity" stimulated by the new crown vaccine, the "new crown protein immunity" response generated by natural immune activation is more extensive
.

Lu Mengji further explained, "In layman's terms, a vaccine is a specific target of the virus, but its efficacy gradually decreases as the new coronavirus strain continues to mutate
.

In contrast, the new coronavirus protein targeted by natural immunity is more 'broad-spectrum' and is relatively less affected by strain variation
.

"This may be one of the important reasons why many overseas countries experienced a wave of epidemic peaks at the beginning of the year, but now they are gradually easing and normalizing
.

Lu Mengji told the "medical community" that some overseas scholars believe that on the basis of the original vaccination , Omicron infection is equivalent to an immunity boost
.

But Lu Mengji also reminded that this conclusion cannot be simply understood as: active infection with the new coronavirus is equivalent to strengthening immunity
.

"For high-risk groups and unvaccinated people, even A reduced virulence variant of Omicron, infection still poses a significant health risk
.

This is also the reason why the early overseas 'herd immunity' strategy was criticized.
There was no effective vaccine at that time, and it was a last resort
.

"And now the most important thing is to increase the vaccination rate, provide basic immune protection for the population, and minimize the health risk after contracting the new crown
.

Lu Mengji said, "On this basis, in the future, it is possible for us to overcome the long-term threat of the new crown through repeated contact with the virus and exert our own immunity
.

"Reference: [1] Comparing SARS-CoV-2 natural immunity to vaccine-induced immunity: reinfections versus breakthrough infections, https:// ]Protective immunity after recovery from SARS-CoV-2 infection, https:// of COVID-19 Among Unvaccinated Adults With Prior COVID-19, https://jamanetwork.
com/journals/jamanetworkopen/fullarticle/2791312 Source: Editor in charge of the medical community: Zheng Huaju Proofreading: Zang Hengjia’s wonderful review in the past confirmed that 3 injections of these two vaccines can prevent severe and Death, the protective power exceeds 97%! What is the protective power of different new crown vaccines? How long is the protection period of the new crown vaccine according to the theoretical data given by the latest research? What should I do if the protective power drops? , but does not make any commitments and guarantees as to the timeliness of the published content, and the accuracy and completeness of the cited information (if any), nor does it assume that the content is outdated, the cited information may be inaccurate or Any responsibility arising from incompleteness, etc.

Please
check the relevant parties when adopting or using this as the basis for decision-making
.