An effective COVID-19 vaccine that completes phase 3 trials after being administered to 20,000 individuals with very few or no serious effects “is well worth taking”, a local medical paper has reassured.
The study is even more relevant in light of results showing 90 per cent efficacy of a vaccine by Pfizer and BioNTech, announced on Monday and hailed as very good news in the fight against COVID-19.
“The odds are still in your favour if you take a vaccine that has had no side effects than having COVID-19,” one of its authors, consultant paediatrician Victor Grech, explained in a nutshell in a study published recently in the Early Human Development journal.
“Many question the safety of vaccines developed with such alacrity, commonly citing potential hypothetical and unknown side effects, including serious adverse events including death – a possibility especially if vaccines are not tested rigorously,” Grech and co-author Neville Calleja, director at the Department for Policy in Health within the Health Ministry, said.
“But if trialled and tested appropriately, albeit with alacrity, then it is as safe as the rest of the vaccines that we have in the fridge,” Grech insisted.
Titled Theoretical novel COVID-19 vaccination risk of rare and severe adverse events versus COVID-19 mortality, the paper outlines the risk of such hypothetical events after a vaccine has gone through the appropriate testing phases and compares this to the estimated death rate from COVID-19 after factoring in asymptomatic cases.
Vaccines are given to healthy multitudes and for this reason they must adhere to high safety standards, the paper points out.
Their development usually takes years of testing. However, due to the potential for large-scale pandemic morbidity and mortality, successful COVID-19 vaccines are likely to be widely available within 12 to 18 months of the initial onset of this pandemic.
It has been estimated that the healthcare financial impact for patients suffering from what is termed ‘long COVID’ – lasting illness and chronic symptoms after recovery – is equivalent to that of elderly patients with severe chronic diseases, the paper says.
Up to 90 per cent of symptomatic patients may experience symptoms, including fatigue, dyspnoea, joint and chest pains after onset.
“This has enormous public health implications, particularly pertaining to younger and previously healthy individuals, who, despite lacking significant comorbidities, fail to return to their baseline functional status,” it says.
Grech said it is, therefore, even more important to stay in control of COVID-19 to limit the damage and costs to Mater Dei Hospital, public health and the social services and healthcare required for chronic COVID-19 cases.
The bottom line is the longer the virus circulates in the absence of herd immunity, despite precautions, it will continue to inflict morbidity and mortality.
Quoting US epidemiologist Michael Osterholm, the paper concludes that: “We were not sure what this virus would do because we have never witnessed a pandemic of a coronavirus before.
“Now, we know it is kind of a super forest fire. It just keeps burning and burning and burning wherever there is human wood.”
Testing phases
Pre-clinical stage: Animals are tested with vaccine candidates to check for the elicitation of an immune response. This is followed by three phases of clinical tests.
Phase 1: A small group of volunteers are vaccinated to determine safety and the nature of the immune response provoked.
Phase 2: Several hundred volunteers are vaccinated to confirm safety and determine optimum dosages.
Phase 3: Thousands of volunteers are enrolled to further confirm vaccine safety including the potential to elicit rare side effects and further delineate vaccine effectiveness. These trials include a control group, which is administered a placebo.
Volunteers are not deliberately exposed to the disease but the vaccine is administered to cohorts from locations with a high incidence of the disease, allowing an eventual comparison between infection frequency rates and disease severity in the vaccine and placebo groups.