Nature Medicine:Vaccination Of This Group Will Not Prevent COVID-19

Breakthrough infection (BTI) means that the novel coronavirus test results of the vaccinators are positive more than 14 days after the completion of vaccination. Previous studies have described the symptoms of long-term sequelae (i.e. long covid) after infection with COVID-19, but it is not clear whether breakthrough COVID-19 infection in vaccinated people will lead to related sequelae.

Long covid, also known as covid-19 long-term sequelae, usually means that covid-19 sequelae symptoms last for more than three months. The research on this problem lags behind that on acute infection.

On May 25, 2022, Nature Medicine published the long covid study after breakthrough vaccine infection led by the US Department of Veterans Affairs. This is also the largest long covid study currently enrolled. VA hospital system is subordinate to the VA Department of the federal government of the United States. It is the only government operated medical institution in the United States and the largest medical institution in the United States.

In this study, researchers recruited a cohort of 33940 Bti patients using the national health care database of the U.S. Department of Veterans Affairs, and maintained a follow-up for 6 months. The other three control groups were several cohorts that were not currently infected with new crowns, namely, the current group (n= 4983491), the historical group (n= 5785273) and the vaccination control group (n   = 2566369). The researchers found that:

Compared with the current control group who had been vaccinated but not yet infected, the Bti population showed a higher risk of death (HR = 1.75, 95% ci: 1.59, 1.93) and the incidence of accidental acute sequelae, such as cardiovascular, coagulation and hematology, gastrointestinal, kidney, mental health, metabolism, musculoskeletal and nervous system diseases (HR = 1.50, 95% ci: 1.46, 1.54) within the first 30 days of the disease after 6 months of infection. Compared with the historical group and the vaccination control group, the above results were still consistent。

The risk of death (HR = 0.66, 95% ci: 0.58, 0.74) and the incidence of acute sequelae (HR = 0.85, 95% ci: 0.82, 0.89) were reduced in vaccinated Bti patients compared with those who had not been vaccinated before; This is consistent with previous research conclusions.

In conclusion, the results show that vaccination before infection can only provide partial protection in the acute late stage of the disease, and has little protective effect in the early stage. Therefore, as the only mitigation strategy, it may not be able to optimally reduce the long-term health consequences of infection with new crowns. The results emphasize that vaccination can reduce the incidence of sequelae, but can not completely eliminate it. It is necessary to continue to optimize the primary prevention strategy of Bti..