May 27, 2022

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The Omicron variant of COVID-19 seems to have milder effects in otherwise-healthy people but it is many times more infectious than previous variants such as Delta and thus can be deadly in those with chronic illness and the elderly, especially those unprotected by at least two vaccinations. 


With many millions of infections around the world every day – and an estimated 200,000 cases daily in Israel alone, there is great concern that many more people will suffer from post-COVID-19 syndrome or long COVID – annoying symptoms that begin a month or more after an easy recovery and can persist for four to 10 months or even longer after that. 

The chances of having long-term symptoms does not seem to be linked to how ill you are when you first get COVID-19. Special clinics for Long Covid patients have already been established in Israel to help them.

Among the common symptoms in children and adults of Long Covid are extreme tiredness; shortness of breath; chest pain or tightness; problems with memory and concentration (“brain fog”); difficulty sleeping (insomnia); heart palpitations; dizziness; a feeling of “pins and needles”; joint pain; depression and anxiety; tinnitus (ringing in the ears) and earaches; feeling sick, diarrhea, stomach aches, loss of appetite; a high temperature, cough, headaches, sore throat, changes to sense of smell or taste; and rashes. rashes

Now, a new Israeli study, soon to be published and to be followed by a series of investigations on the matter, shows a major reduction in the most commonly-reported long-term symptoms of COVID-19 among people vaccinated with at least two doses and infected with the virus compared to non-vaccinated previously-infected individuals. People who were never infected with the virus do not develop Long Covid; those vaccinated and infected reported no more of these symptoms than individuals who were never infected with the virus.


The study, involving over 3,000 participants, showed a 50% to 80% reduction in seven of the 10 most commonly reported long-term symptoms, such as fatigue, headache, weakness and muscle pain, four to 11 months after infection among vaccinated cases compared with unvaccinated ones. 


The research was led by Prof. Michael Edelstein of Bar-Ilan University’s Azrieli Faculty of Medicine in Safed, in collaboration with three of the faculty’s affiliated hospitals – Ziv Medical Center, Poriya Medical Center in Tiberias and the Galilee Medical Center in Nahariya. The findings were reported on the medRxiv pre-print server under the title “The association between vaccination status and reported incidence of post-acute COVID-19 symptoms in Israel.” 


Of the 951 infected individuals included in the study, 340 (36%) reported receiving a single dose and 294 (31%) reported having received at least two doses. Of the 951 infected individuals, 636 (67%) reported at least one symptom during COVID-19 diagnosis. Among the unvaccinated, 69% reported at least one symptom at COVID-19 diagnosis, vs. 57% among those who received two doses and 74% among those who received one dose only.


“A double comparison of vaccinated vs. unvaccinated COVID-19 cases followed by comparing vaccinated COVID-19 cases to people reporting no infection enabled us to show not only that vaccinated people were experiencing much fewer long COVID symptoms than unvaccinated people, but that that they did not report any more symptoms than people never infected,” said Edelstein, whose doctoral student Paul Otiku led the complex data analysis.


This study is the first of comprehensive research on a large cohort of patients – both infected and non-infected with COVID-19 – whose health Edelstein and colleagues will continue to analyze over the coming years to understand the long-term impact of COVID-19. These findings suggest that at least two doses of COVID-19 vaccine are likely to protect against long COVID. These results were not observed in individuals who received just a single dose.


The researchers concluded that undergoing at least two doses of COVID-19 vaccine was associated with a substantial decrease in reporting the most common post-acute COVID-19 symptoms, bringing it back to baseline.