New Delhi, Dec 11 (IANS): After three years of the pandemic, questions are now being raised over certain vaccines and their reported deadly side-effects, including heart attacks, for which there is no substantial proof yet.
If we look at recent global studies published in top peer-reviewed journals, the incidence of myopericarditis (acute heart inflammation) and myocarditis have been found higher in males after the second dose.
A meta-analysis of 23 studies, including 854 patients aged 12 to 20 years with mRNA vaccine-associated myopericarditis (rare acute heart inflammation), this month found that the incidence of myopericarditis was higher in males after the second dose, adding that however, the "overall cases are very low".
The findings, published in JAMA Pediatrics, a journal of JAMA Network, suggest largely low incidence rates and favourable outcomes of Covid vaccine-associated myopericarditis in adolescents and young adults.
Last month, a study in the Journal of the American College of Cardiology found that the incidence of myocarditis, pericarditis or myopericarditis is two- to threefold higher after a second dose of the Moderna Spikevax Covid-19 vaccine when compared to the Pfizer BioNTech Covid-19 vaccine. However, "overall cases of heart inflammation with either vaccine are very rare", it said.
Since the emergency use was authorised, the association of the mRNA-based Covid-19 vaccine with myopericarditis, which is a rare but serious adverse event, has been reported worldwide, especially in adolescents and young adults.
Among individuals who have received Covid-19 vaccines, younger people, females and those who got the second dose of the Moderna Covid vaccine report more side effects from vaccines that may have led to moderate and severe limitations, according to a recent article in Clinical Laboratory News of the American Association for Clinical Chemistry.
The survey compared side effects of Pfizer, Moderna, and Johnson & Johnson COVID-19 vaccines.
These observations from self-reported data might be explained by higher mRNA concentration in the Moderna vaccine, according to researchers. They added that increased side effects in these groups may be associated with additional protective immunity and fewer breakthrough infections, as other studies have shown.
A study done by Queen Mary University of London on the after-effects of Covid on heart and heart-related ailments has found in non-hospitalised patients there is a 2.7 times risk of blood clots and 10 times higher risk of death.
Based on data collected during the first two Covid waves from participants in the UK Biobank study, the research report published in the journal Heart, states that in the case of patients who were hospitalised, there has been a 118 times rise in the number of deaths.
In addition, the study has revealed there has been a 27.6 times rise in incidents of blood clots, 21.6 times increase in cases of heart failure, 17.5 times rise in cases of stroke and 10 times rise in cases of arrhythmia or irregular heartbeat among people who were hospitalised due to Covid-19.
The study states the associated risks were greatest in the first 30 days after infection but remained higher than controls even after this period.
On the other side, A latest analysis published in the journal Frontiers in Medicine found that among those who have recovered from a coronavirus infection, vaccinated people have a halved risk of becoming infected a second time or contracting Covid-19 again with severe symptoms compared to those who are not vaccinated.
Two main results emerged. One shows that vaccination halves the likelihood of Covid-19 reinfections compared to natural immunity alone obtained with a recovery from the virus.
Moreover, data show that even if a second infection occurs, the likelihood of developing severe symptoms is halved in vaccinated people.
Similar levels of protection were observed in people vaccinated with only one dose, even for the Omicron variant and up to 12 months after the last infection.
The last word is yet to be out on the vaccine's dangerous side-effects, in any, but most global studies find that the vaccine's benefits far outweigh the risk associated with Covid and Long Covid.