Systematic tracking of SARS-CoV-2 variants should be a top priority in Guyana
A top-ranking science journal (N. Phillips, Nature, 2021, 590, 382) recently polled immunologists, virologists and infectious disease experts (the people who best understand virus science, how their structure changes with time and their epidemiology) working with Coronaviruses on whether they think it will be eradicated (gotten rid of completely with zero cases of infection globally). The survey showed that 90% of them think that it will become endemic but less potent as more of the world’s population becomes immunised. Endemic means that it will circulate in sections of the world for many years to come with a risk of outbreaks in regions where it has been eliminated or there will be seasonal outbreaks. Polio is endemic in Afghanistan and Pakistan; global vaccination campaigns allowed its elimination from the rest of the world exemplifying that vaccines work!
That SARS-CoV-2 is here to stay is reasoned from the fact that we have four endemic coronaviruses currently in global circulation that infect humans causing the common cold – 229E, NL63, OC43 and HKUI (https://www.cdc.gov/coronavirus/ge neral-information.html). OC43 is speculated to have caused the deadly 1889-1890 pandemic or the “Russian Flu” however that could not be confirmed as technologies such as genome sequencing were not in existence. Genome sequencing reads out the genetic code of the virus that infected a particular person allowing it to be compared to many others. SARS-CoV-2 was detected and identified rapidly using genome sequencing. Its genome sequence was made available on the 10th January 2020, less than a month after the WHO was informed of pneumonia cases from an unknown disease in Wuhan (COVID-19). Influenza (flu) is also endemic in tropical regions with seasonal epidemics elsewhere and there exists many commercial vaccines that target multiple strains. One of these targeted strains is H1N1, notorious for its mutation rate (note, the flu virus is structurally different from Coronaviruses and mutates at a much faster rate). So, we are still vaccinating, 100 years later, against a descendant of the H1N1 strain responsible for the deadly 1918 pandemic; a much less potent version. The WHO has a robust Global Influenza Program which collects epidemiological and virology data on circulating flu strains from thousands of samples. They pass this information and strain recommendations to vaccine developers to allow adjustment
of the seasonal flu vaccine every year, for Northern and Southern hemispheres.
With SARS-CoV-2 in circulation for a long time there will be several challenges. Vaccination allows us to be immunised and build up antibodies to fight off the virus but one large scale study (J.M. Dan et al., Science, 2021, 371, 587) shows that antibodies begin to decline 6 to 8 months after vaccination (this is where booster shots come in). So, the length of time immunisation lasts is still being worked out. This along with the race against emergence of more transmissible variants may carry us into years before enough of the global population has been immunised to the point of virus elimination. We are now seeing the devastating impact of this in Brazil and India with the P.1 and B.1.617 variants dominating, respectively. The good news is ongoing studies show that we have vaccines that are still effective against new variants (to date) but with varying degrees of reduced efficacies. There is only one case (to date) where a vaccine was ineffective and its rollout stopped – the Oxford-AstraZeneca vaccine in South Africa where the B.1.351 variant dominates. It’s definitely not easy staying ahead of the virus!
Genome surveillance data lets us know specifically and quickly what we’re dealing with and the prevalence of a particular variant over time. It lets you pinpoint the mutation(s) on the virus that may be problematic, allowing vaccines to be adjusted to maintain efficacy. Of course, this takes time and if the virus continues to spread unchecked in populations, we’re going to be chasing variants for a long time – the more unvaccinated and susceptible people we have in the population the greater the risk of more variants emerging. I think Guyana is doing well with its vaccination campaign given the major challenge the developing world faces with equitable access to vaccines and supply shortages which is even a problem for rich countries. However, I think systematic tracking of variants should be a top priority in
Guyana as it can only serve to enhance and improve public health policies and countermeasures for the long term. South Africa ramped up their genome surveillance programme with the dire need to track the disease progression with the more contagious B.1.351 dominating. Canada recently announced in its federal budget $400 million dollars dedicated to a new Pan-Canadian Genomics Strategy. This recognizes the major role genomics plays in helping to track and fight COVID-19. The US accused of lagging behind globally because they lacked widespread genetic sequencing has now significantly upped their surveillance game too as more variants have been detected in circulation (e.g., B.1.526 in New York, B.1.427 and B.1.429 in California).
These days genome sequencing is routine and a simple high throughput benchtop instrument costs around US$2000050000. I think it can be incorporated into existing testing/analytical labs in Guyana for ease of maintenance. Collaborating with CARPHA to test for new variants is great but in my opinion the time constraints to get information is not practical especially if an emergency situation arises. Systematic tracking of variants on a large scale can only serve to improve and accelerate effective public health strategies.
Finally, if you haven’t been vaccinated as yet, I implore you to do so. Remember vaccines work best in communities not individuals and this is the reason we need to keep practising other public health measures such as wearing a mask (until we have enough people immunised). The H1N1 influenza strain went from deadly in a pandemic to mainly causing mild illness while OC43 (a Coronavirus) may have gone from pandemic to common cold but it took over 100 years! We don’t have that time! We know better and are more technological advanced, we just all need to do our parts!