Features
Some Vital Information About The Coronavirus Vaccines
by Dr B. J. C. Perera
Specialist Consultant Paediatrician and Honorary Senior Fellow, Postgraduate Institute of Medicine, University of Colombo, Sri Lanka.
The vaccines against SARS-CoV-2 organism that causes COVID-19 disease are now being rolled out with great enthusiasm in many countries. Any vaccine, by definition, is a biological preparation that provides active acquired immunity to a particular infectious disease. All vaccines help the normal defence mechanisms of the human body to fight infective organisms. A vaccine typically contains an organic preparation from disease-causing microorganism, or since the beginning of the 21st century, of compounds made synthetically that resemble it; the latter being formulated mostly by genetic engineering. Although most vaccines prevent people contracting the disease, some may only modify the symptoms, signs and reduce mortality from infectious agents.
There are four categories of vaccines against COVID-19 in clinical trials: whole virus vaccines, protein subunit vaccines, viral vector vaccines and nucleic acid (RNA and mRNA) vaccines. Some of them try to smuggle the antigen into the body, others use the body’s own cells to make the viral antigen. The exact ways in which these vaccines work differ somewhat but such minutiae should not be of major interest to the readership of this article. The vaccine that is currently used in Sri Lanka is a viral vector vaccine which uses a modified Chimpanzee adenovirus as the vehicle that takes the coronavirus antigen into the human body.
The vaccine that is used presently in Sri Lanka has produced some side-effects in certain individuals. These are mostly mild in the vast majority and consist of chills (feeling cold), fever, general muscle pains and pain at the site of the injection, all for just a couple of days. Most people get relief of these with simple pain-killers such as paracetamol. Very, very occasionally, there have been rather marked undesirable effects that have needed hospitalization. These too have resolved with adequate treatment and have not left any long-lasting effects. As far as we can say, some of these side-effects were mostly seen in younger individuals and this is also a well-known phenomenon recognized by the international scientific community. All in all, when all considerations are balanced, this vaccine is quite safe.
The clinical effectiveness of the vaccine used in our country is quite well established. It does prevent to a significant degree, the incidence of more severe disease in those who have contracted the virus and it significantly reduces the number of deaths. This was the primary reason to champion the vaccine as a protective mechanism against the disease.
Initially it was thought that it does not prevent susceptible individuals from getting infected by the virus but only reduces the severity of the disease, as well as the need for intensive care and significantly reduces the number of deaths. HOWEVER, MORE RECENT INFORMATION, PARTICULARLY FROM THE UNITED KINGDOM, INDICATES THAT THE VACCINE COULD PLAY A ROLE IN REDUCING THE NUMBERS OF PEOPLE CONTRACTING THE DISEASE AS WELL.
This information is still anecdotal evidence and data from personal communications. We have to wait for proven scientific evidence for it. The latest report in a preprint publication (DOI: 10.22541/au.161420511.12987747/v1), dated 24 February 2021, researchers from the University of Cambridge report that in nearly 9000 coronavirus tests done on healthcare workers in Cambridge, UK, they found that asymptomatic infections fell by 75 per cent 12 days after they got one dose of the Pfizer/BioNTech vaccine. There was a similar reduction in symptomatic infections. The researchers further commented that this finding is significant because it shows the vaccine will greatly reduce the spread of the virus. It was already clear from clinical trials and previous studies that the Pfizer vaccine is highly effective at preventing symptomatic infections but what was not known was whether vaccinated people might still get infected without symptoms and potentially pass the disease on to others. We are beginning to see some evidence that the vaccines may also reduce the risk of contracting the disease.
In our resplendent isle it is still very early days. We have only just started mass vaccinations. Judging by the efforts taken by the general public, they are most receptive to receiving the vaccine. Yet for all that, we do not have sufficient supplies of the vaccine to vaccinate as many as possible and to even go on to vaccinate at least 70 per cent of our entire populace to ensure herd immunity. If and when stocks are made available, the general public should have NO QUALMS WHATSOEVER to join in this fight against COVID-19 and get the vaccine pronto.
Yet for all this, ONE THING MUST BE VERY CLEARLY UNDERSTOOD. It has to be reiterated and reemphasized that, at the present time, the vaccine is not a panacea for all ills in our fight against the coronavirus. It DOES NOT give anyone carte blanche or complete freedom to act as one wishes. The vaccine does not, I repeat DOES NOT give any covidiots around unrestricted permission or unabridged power to get back to the ‘previous normal’. The advocated health guidelines MUST still be followed. This is an absolute and imperative ‘MUST’. There must be scrupulous avoidance of crowds. There must be social distancing. There must be unrestricted washing of hands and there must be wearing of masks. We cannot, I repeat CANNOT, get away from this ‘new normal’; most definitely not as yet.
Hopefully, a time may come in the future when we can tell this little blight of a coronavirus to simply ‘go to hell’. It is very definitely not time for that, certainly not as yet. After suffering for over a year, there is a glimmer of hope; there is some light at the end of the tunnel. As I have written before, Mother Nature has her own natural cycles. She will do it her way. Perhaps, in a few more months, we can look forward to the day in the future, where we can pull out the flags and the bunting to celebrate victory over an enemy that brought even the most powerful of nations to their knees. Healthy optimism, but not recklessness, is the desperate need of the hour.