MOSCOW , Dec 21, Vladislav Strekopytov.Scientists in the UK analyzed health data from more than a million people in the first week after vaccination. It turned out that the reaction to the vaccine sometimes makes it difficult to recognize the onset of COVID-19 in time. How to distinguish the side effects of the drug from the first symptoms of the disease and what to do if in doubt — in the article .
Artificial intelligence is powerless
Coronavirus is often infected immediately before or after vaccination. The response to a vaccine largely coincides with the early manifestations of COVID-19. These include high fever, fatigue, headache and muscle pain, nausea, and loss of appetite. In such cases, it is easy to miss the onset of the disease, especially since the full protection of the body occurs only in the second week after the injection, and in the first days the body is especially vulnerable.
British scientists analyzedstatistics collected using the CSS smartphone app (COVID-19 simptom study). Initially, it was created to track the manifestations of COVID-19, but now it is also used to study the side effects of vaccinations. People who have been vaccinated are asked to enter their health information there daily. And if there are symptoms, they offer to be tested for coronavirus.
The authors collected data from 1,072,313 members registered with CSS. All of them received the first dose of Pfizer-BioNTech or AstraZeneca from December 8, 2020 to May 17, 2021. There were no complaints during the procedure. Within a week of vaccination, 362,770 people reported symptoms and 14,842 were tested for SARS-CoV-2. In 150, the results were positive, in 14,692 they were negative. These two groups became the subject of comparative analysis.
Information was adjusted for comorbidities and demographics such as gender, age, and ethnicity. In a previous overview study, also based on data from the CSS application, the authors noted that side effects after vaccination, including severe ones, such as thrombocytopenia (impaired platelet production) and isolated cases of myocardial inflammation, are more common in young people. The elderly tolerate vaccination more easily. With regard to COVID-19, the picture is reversed here: in young people, the coronavirus is often asymptomatic.
The machine learning model took into account all 28 registered symptoms. Separately, the authors analyzed the three main clinical manifestations of COVID-19, which serve as an indication for PCR testing in the UK. This is a fever, persistent cough and impaired sense of smell.
The analysis showed that there are no signs that allow us to confidently distinguish between the reaction to the vaccine and the onset of the disease. This has not been possible with machine models or with accepted symptom profiles. Most of the three main manifestations of the disease were absent, they were recorded only in 62 participants with a positive test and in 3414 with a negative one. At the same time, many who have confirmed the infection noted only fatigue, headache and muscle pain — the most common side effects of the vaccine. » data-crop-ratio=»0.91674127126231″ data-crop-width=»600″ data-crop-height=»550″ data-source-sid=»cc_by_40″ class=»lazyload» width=»1920″ height=» 1760″ decoding=»async» />
A Matter of Time
As it turned out, the symptoms are difficult to divide not only by type, but also by the strength and time of occurrence. Fatigue, fever, headache and muscle pain usually appear on the first day after vaccination, and the peak occurs on the third day. These symptoms are noted by 76 percent of those vaccinated. Young people have a higher percentage — up to 83.
The difference is that on the third day after immunization, these symptoms usually disappear, while with COVID-19, on the contrary, they increase and reach a maximum on the seventh day from infection. In addition, the infected increase in sore throat, sneezing, hoarseness, coughing, brain fog. Hence the conclusion: in the first two or three days after vaccination, side effects can mask the onset of COVID-19, but if the symptoms persist and worsen, this is definitely a cause for concern.
“The first manifestations of COVID-19 are very similar to the consequences of vaccination,” confirms the head of the Therapeutic Clinic of the European Medical Center, Honored Doctor of Russia, Candidate of Medical Sciences Vladimir Sibirsky. “Therefore, it is very important to take into account the time factor. headaches and muscle aches usually resolve within a day, if they last more than 24 hours and are accompanied by coughing, runny nose, smell and taste disturbances, it is very likely that these are signs of a coronavirus or some other viral infection.
“Side effects can develop on the first or second day after vaccination,” explains Elena Tkach, deputy chief physician of the Polyclinika.ru branch of the network of medical centers, Candidate of Medical Sciences. “Usually this is a short flu-like syndrome with chills, fever, joint pain muscles, weakness, general malaise and headache.Nausea, dyspepsia and loss of appetite are noted less frequently.Some patients have allergic reactions.If the symptoms persist for more than three days, it is necessary to call a doctor and take a PCR test.
An unambiguous answer is testing
Scientists note: all the given dates are approximate, since in no case was the exact time of infection known. In addition, people who caught the virus before vaccination did not know about it, which means that the disease proceeded in an asymptomatic form. All this complicates the development of criteria by which to distinguish the symptoms of early covid from the side effects of the vaccine. In addition, experts point out that the authors of the study used data only on Pfizer-BioNTech and AstraZeneca, so it is worthwhile to extend their conclusions to other drugs with some caution.
«The fact is that Pfizer and Moderna vaccines are quite reactogenic. In In most cases, their side effects are stronger than those of Johnson & Johnson and Sputnik V,” says Vladimir Sibirsky. “As for domestic drugs, according to my observations, reactions occur quite rarely.”
In any case, scientists recommend even those who have recently been vaccinated to stay at home and get tested at the slightest suspicion of COVID-19 in order to identify the virus earlier and prevent its spread.