Tue, 2021-10-05 11:09 by Dr. Colin Alert
Covid vaccines: what they can and can’t do!
Dr. Colin Alert, MB BS, DM. FCCFP
Family Physician.
Shortly after the start of the covid pandemic, around February 2020, it was stated that one of the major public health goals of dealing with this epidemic was to “flatten the curve”: to reduce the number of persons affected by this new virus so that our health services were not overwhelmed. This was especially important for Barbados as it was reported in the press that the bed occupancy in the Queen Elizabeth Hospital (QEH) on wards likely to house persons affected by any infectious disease was a whopping 200% at the time. It was clear that an alternative medical strategy would be needed to reduce the number of persons that would need to be hospitalized.
The short term solution consisted of the three Ws: Wash your hands, Wear your mask, and Watch your distancing. No single one of these is independently effective, but in combination offered our best opportunity to limit the spread of covid, until a better solution could be found. Because vaccinations has been historically used to limit the impact of infectious diseases, scientific minds and financial resources were channeled to find a vaccine (s) that would be effective in the fight against covid. With a headstart gained from studying ‘cousin’ corona viruses that caused geographically localized epidemics earlier in this century, scientists were able to develop a number of vaccines that gave us some more survival tools.
The historical goal of vaccination was to avoid infant mortality, and vaccinating our children is almost universally accepted. When we recall that the smallpox caused more than 5 million deaths before the vaccination was introduced, and that the measles caused more than 2.5 million deaths until a few years ago, today we can say that the smallpox is over and the measles has been reduced very dramatically. But we can also see that vaccination is able to give herd protection for these diseases. So if a considerable part of the population is protected, the circulation of the infection is the reduced. And vaccines are very useful from an economic point of view, preventing disease being much cheaper than treating disease.
The human immune system begins to age from the age of 25 onwards. Apart for ageing, many conditions also are associated with an increased susceptibility to infectious disease: this list includes obesity, diabetes, hypertension, the same list of conditions that filled up the QEH in the first place (and we now hear daily that have combined with covid to take a life of unfortunate individuals at the isolation centre). Therefore the benefit of vaccination, which stimulate the immune system to fight specific diseases, increases rapidly with age and the number of co-morbidities present. Vaccination is one, if not the most important, preventive measure in elderly people, and in people with co-morbidities.
The phenomena of unvaccinated individuals, i.e. people who are not willing or able to take the vaccine, threatens efforts to establish ‘herd immunity’, a scenario in which such a large proportion of the community are effectively immunized that the virus spread within the community is stopped (or at least significantly slowed). Unfortunately the unvaccinated includes a multitude of groups, including many who simply lack important medical information (vaccine hesitant), some who cannot take the vaccine for a variety of medical reasons, and some anti-vaxers, many of whom are just obstinate.
We have available here in Barbados three vaccines, available free of cost to all receptive Barbadians. Although they vary slightly in their effectiveness, and the actual effectiveness depends of the specific virus mutation one is talking about, to date all the vaccines significantly lower the possibility of a vaccinated individual person becoming seriously ill, needing intensive care in hospital, or even dying. But this does not mean that a vaccinated person cannot be infected by (a mutant strain of) the covid virus, or even be fatally affected. In most countries the ratio of covid deaths in the unvaccinated is 95-99% compared to the vaccinated. The unvaccinated persons are also more likely to fill our isolation facilities, and to spread the virus to other unvaccinated persons.
A vaccinated person is less likely to be able to spread the virus than an unvaccinated person, but this chance is not 0%. Thus vaccination does not allow the vaccinated individual to abandon the W’s, unless everyone in the community is vaccinated – an unlikely scenario – or spread of the virus has been completely halted. (Meanwhile, the virus is mutating or evolving in such a way as to continue multiplying within a community, and across different communities, finding ways to escape the effects of the vaccines.)
It is not clear how close our health care service is to breaking point, such has been the effect of this covid pandemic. It is not clear how many resources the government can keep funneling into dealing with covid, but the resources cannot be infinite. Our health services have had to divert resources away from dealing with our ‘usual’ comorbidities, and the rate of deaths seems to be increasing. We have not been able to reduce the numbers of persons being infected, being isolated or dying. Pandemics have always been around, but their number will increase with globalization. Social unrest and economic crisis are often consequences of pandemics. Vaccination is the single most effective way to “flatten this curve” and therefore in the interest of all people.