A peer-reviewed study was published in the New Journal England of Medicine on August 25, 2021, reporting on the safety of the messenger RNA vaccine against SARS-CoV-2.
This is one of the most significant studies in the world involving more than 800,000 vaccinees and control groups.
In addition, more than 100,000 Covid-19 patients and control groups were involved in the study.
This study reported extensively on the adverse effects of the Covid-19 vaccine and Covid-19 natural infection.
Side effects of vaccination included acute kidney injury, appendicitis, arrhythmia, deep vein thrombosis, herpes zoster infection, intracranial haemorrhage, lymphadenopathy, myocardial infarction, myocarditis, pericarditis, and pulmonary oedema embolism and others.
Covid-19 vaccination was most strongly associated with an elevated risk of myocarditis (2.7 events per 100,000 persons) and lymphadenopathy (78.4 events per 100,000 persons).
However, Covid-19 natural infection has been strongly associated with even more adverse effects and a higher incidence rate than the Covid-19 vaccine.
11.0 events per 100,000 persons reported myocarditis, or heart muscle inflammation after natural infection, an almost fourfold risk when compared to the adverse effect of Covid-19 vaccination.
In addition, Covid-19 natural infection was associated with a high incidence rate of acute kidney injury (125 events per 100,000 persons), arrhythmia (166 events per 100,000 persons), deep-vein thrombosis (43 events per 100,000 persons), and pulmonary embolism (62 events per 100,000 persons), while Covid-19 vaccination reported no such adverse effects.
Despite overwhelming evidence of the various adverse effects of Covid-19 natural infection, patients receiving vaccination reported higher lymphadenopathy incidences than Covid-19 natural infection (78 versus three events per 100,000 persons).
Lymphadenopathy is defined as the swelling of the lymph nodes.
Lymph nodes are an essential part of our immune system, because they contains lymphocytes, a subset of white blood cells that help the body fight infection and disease.
Swollen lymph nodes are not a reason to worry, because it is simply a sign that your immune system is reacting to the Covid-19 vaccine.
Therefore, there is no need to worry, should you experience swollen lymph nodes after receiving Covid-19 vaccination.
Limited evidence reported adverse effects of the Covid-19 vaccine and natural infection in Malaysia.
Health director-general Dr Noor Hisham Abdullah reported on June 11 that two-thirds of 1,004 patients in Categories Four and Five suffer from long Covid.
Long Covid is a condition in which a Covid-19 patient still shows certain symptoms for a period of up to 12 weeks or more after supposed recovery. Such symptoms cannot be medically explained.
The five most common symptoms experienced by long Covid patients are fatigue, breathing difficulties while engaging in activities, difficulty sleeping at night, coughing and anxiety.
In contrast, former health minister Dr Adham Baba reported on June 14 that only 240 cases involved adverse effects per 100,000 patients after receiving Covid-19 vaccination.
He added that only nine cases per 100,000 patients were severe cases in need of short-term hospitalisation.
Given the few adverse effects of Covid-19 vaccination, we need to do more to promote vaccination among family members and friends.
The National Covid-19 Immunisation Programme (PICK) is in full swing throughout Malaysia, with more than 43 per cent of the population having completed their Covid-19 vaccinations.
However, about 2.2 million adults in Malaysia aged 18 years and above have yet to register for Covid-19 vaccination as of August 28.
Convince your family members and friends who are vaccine-hesitant to register for Covid-19 vaccination.
Ahmad Mahfuz Gazali is a senior lecturer at the Faculty of Industrial Sciences and Technology, Universiti Malaysia Pahang.
- This is the personal opinion of the writer or publication and does not necessarily represent the views of CodeBlue.