In a recent article published on the medRxiv * prepress server, researchers in Norway and Sweden compared medical complaints after coronavirus 2 (SARS-CoV-2) infection with severe acute respiratory syndrome after the second and third SARS-CoV-2 vaccination dose.
Study: Medical complaints after SARS-CoV-2 mRNA vaccination of 3 vs 2 doses. Image credit: MattLphotography / Shutterstock
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After mild coronavirus disease 2019 (COVID-19), the most frequent persistent complaints are fatigue and respiratory problems such as shortness of breath and coughing, commonly referred to as post-COVID condition.
The authors of the present study recently reported that these complaints are equally common after SARS-CoV-2 Omicron and Delta infections. However, there is uncertainty about the impact of COVID-19 messenger ribonucleic acid (mRNA) vaccination on these post-COVID complaints. Furthermore, it is unknown whether the reactogenicity of the vaccine can lead to these complaints in the short and long term.
According to a recent rapid review, people who received one or two doses of the SARS-CoV-2 vaccine were less likely to experience symptoms of COVID-19. A better understanding of the overall effects of the third dose of COVID-19 vaccine on medical complaints is required to understand its implications for health services. Any apparent effect of health services could be considered in deciding whether to administer the fourth dose of the SARS-CoV-2 vaccine.
About the study
In the current work, researchers from the Norwegian Institute of Public Health, the University of Oslo, Oslo University Hospital, Oslo and Lund University analyzed whether those who received three doses of SARS-CoV vaccine -2 in the 20 and 30 weeks after the second dose. they had a different risk of suffering medical complaints after COVID-19 about 90 days after those who did not receive the third vaccine. They also assessed whether any varied incidence was more likely associated with different cases of COVID-19 between groups.
In the prospective cohort investigation, the team used information from the Norwegian Emergency Preparedness Registry to assess people between the ages of 18 and 70 who resided in Norway on January 1, 2021. The research included men and women of working age in two cohorts: 18: -44 and 45-70 years.
The scientists acquired an equal sample of 138,581 participants between the ages of 18 and 70 who received the third dose of the vaccine between 20 and 30 weeks after receiving the second dose and an equally important control cohort that did not. To do this, they used an exact longitudinal match 1: 1 the days after vaccination of two doses, the natural month and a set of covariates. The key results of the study were medical records showing frequent post-COVID complaints found in primary care for about 90 days after vaccination.
Results
The results of the study indicated that after the third dose of COVID-19 vaccination, the projected 90-day cumulative incidence of medical complaints after SARS-CoV-2 infection ranged from 70 to 5,000. per 100,000 people, depending on the type of complaint.
Three doses of vaccination caused fewer medical complaints among people aged 18 to 44; that is, 662 respondents (662 per 100,000 vaccinated) reported fatigue, 160 reported difficulty breathing, and 65 reported brain fog. The team noted that, compared to those who were not vaccinated, individuals who received three doses of the vaccine at intervals of 20 to 30 weeks after the second dose had a reduced risk of 20% to 40% of suffering. post-COVID medical complaints up to 90. days later. No decrease in the onset of cough, musculoskeletal pain, or heart palpitations was observed.
After the exclusion of subjects aged 18 to 44 years according to the date of the positive test for COVID-19, these absolute differences were less pronounced. This inference suggested that variations in the incidence of COVID-19 may have contributed to variations in complaints.
Similar studies that censored positive evidence produced more unclear results. However, higher estimates for people between 45 and 70 years old. This observation was due to a bias related to healthy vaccinations.
It is important to note that none of the current analyzes revealed any immediate increase in the results of incidents of medical complaints after the third injection of the mRNA vaccine, demonstrating that possible side effects may not put a strain on the facilities. of primary care.
Conclusions
The authors stated that the present study was the first to evaluate how the third dose of SARS-CoV-2 mRNA vaccine may affect complaints related to the observed vaccination in primary care.
The study’s findings suggested that subjects vaccinated against three-dose COVID-19 experienced a lower complaint rate compared to controls equated with two-dose vaccination. Studies comparing analyzes with and without filtering positive SARS-CoV-2 tests indicated that a lower incidence of COVID-19 among those who received three doses of vaccination could explain this decrease.
Overall, the present study showed that complaints of COVID-19 and post-COVID were less frequent in those who received a third dose of the SARS-CoV-2 mRNA vaccine between 20 and 30 weeks after the second. dose than in their matching controls. . This can be explained at least in part by variations in SARS-CoV-2 incidences. These results may be relevant in deciding when and whether a fourth injection of the mRNA vaccine should be given in public health settings.
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medRxiv publishes preliminary scientific reports that are not peer-reviewed and therefore should not be considered conclusive, guided by clinical practice or health-related behavior, or treated as established information.