An emerging disease expert has voiced concern over the apparent link between a spate of heart-related symptoms among recipients of vaccines made using the mRNA technique, saying even though the risk is low, its impact on the heart is rather sudden and severe.
Citing the results of a study by German doctors, which were published on Nov 27, Dr Thiravat Hemachudha, chief of the Thai Red Cross's Emerging Infectious Diseases Health Science Centre, said there have been at least 25 cases of sudden death occurring within a week from a patient receiving an mRNA vaccine.
All the deaths were recorded as resulting from either myocarditis or pericarditis and had occurred in people aged between 45-75 who had received an mRNA vaccine, he said in his Facebook post.
Myocarditis is inflammation of the heart muscle, and pericarditis is inflammation of the outer lining of the heart.
All these 25 cases of heart conditions were confirmed in autopsies carried out within a week after an mRNA vaccination, he said.
The actual figures of people suffering these two heart conditions might be a lot higher than those officially recorded as previous studies into the link between mRNA vaccination and these heart conditions conducted worldwide were all retrospective investigations which didn't include sudden death, he said.
Virologist Yong Poovorawan, meanwhile, offered a guide as to how many shots of the Covid-19 vaccine one should get at the moment.
In most cases, four shots of the vaccine are sufficient for protection against severe coronavirus infection, said Prof Dr Yong, chief of the Centre of Excellence in Clinical Virology at Chulalongkorn University's Faculty of Medicine.
Only those who have an underlying medical condition and people aged 60 and over should get a fifth shot four to six months after receiving the fourth shot, he said.
Covid-19 infection is equivalent to receiving a shot of the Covid-19 vaccine and counted altogether with the shots received, he said, adding that a combination of Covid-19 vaccination and natural immunity after infection is believed to offer the most effective immunity against coronavirus infection.
The local infection rate should also be taken into consideration when considering whether to seek a further booster, he added.
