(600+ words, 3-4 minutes; Why read this? How to mitigate the impact of variants, leverage vaccines, and keep battle readiness for next surge and achieve business/social objectives with minimal disruptions).
To the unsuspecting mind, COVID-19 is done and dusted. However, scientists and the medical community are well aware that this is not the case. To those who believe COVID-19 is over, I am sharing my perspective on why COVID-19 is not yet done.
- Variants: Mutant variants such as B 18.104.22.168, D614G, and N501V gradually dominating the global landscape. Over more than 45 countries are currently subdued with the new variants. Understand, the new mutations are like new viruses, and the human immune system needs to build the immune response once again. For this same reason, we vaccinate yearly for Influenza because the virus changes its structure due to a phenomenon called ‘antigenic shift and antigenic drift.’ Such changes are more frequent with Coronavirus (SARS CoV2).
- Herd Immunity: When a sufficient percent of the population has developed immunity to a stable variant (not changing genome) of the virus. This threshold is determined by several factors, including transmissibility of the disease. The latest strain, which supposedly originated in South Africa, is considered 50-70% more transmissible than the original SARS CoV2, which originated from Wuhan. Increase transmissibility does not translate to increased mortality and case fatality ratio. However, it impacts the binding of the endogenous antibodies. Thus increase transmissibility is a double edge sword. It has the potential for faster spread amongst the population, ultimately expanding the herd immunity for that strain; however, it comes with a negative side that the immune response developed to earlier exposure is not adequate. Thus the herd immunity acquired may not necessarily be sufficient to protect the population.
- Vaccines: In Dec 2020, I wrote a blog on the variants and their potential implications on the virus. Recent reports indicate that the vaccine developed by Moderna may not be affected due to these variants. Novavax, an integral initiative of Operation Warp, has reported that its vaccine may not have the same efficacy level against the variant from South Africa. It is too early to confirm a similar effect of the variant viruses on the leading vaccines. Vaccine rollout is hampered by manufacturing capacity, logistics, and the complex rollout to diverse population segments. However, the biggest challenge is the slow pace of adoption and the misconception about vaccines. Anti-science has taken center stage, and those with rationale science are facing an upstream battle.
Thus a Tripple whammy of variants, vaccines, and lack of herd immunity will potentially have a significant toll in containing and mitigating the virus.
How can speedy vaccine rollout help? Let us understand that vaccines and natural infections both work in tandem to counter the virus and build a sufficient threshold of immunity. However, that threshold is brought down due to changes to the virus (variants), thus requiring a better adoption of the virus to achieve a similar threshold for the population. In a hypothetical scenario, imagine a threshold of, say, 60 (60-80) is required for meaningful protection of the population. We can achieve this number by either – a) natural immunity plus b) the immunity acquired from the vaccine. Presume the equation is 25+35=60. If those inoculated with vaccines increase, naturally, we will reach the threshold early.
Conversely, if the variants keep changing, the total exposure in the population will reduce. Thus, the herd immunity is lowered (due to a newer variant). Naturally, the vaccine rolls out, and adoption has to compensate to achieve that threshold. A myriad of factors will influence vaccine rollout or adoption that needs a closer review by the policymakers and administrators. There is no place for complacency. COVID-19 is not over, and leaning on luck is not a robust strategy. “If we give the virus a chance to do its worst, it will.” – Dr. Michel Nussenzweig, an immunologist at Rockefeller University in New York.
“Right now, the immediate future is not the time to relax.” Angela Rasmussen, a virologist at the Georgetown Center for Global Health Science and Security in Washington, D.C.
“We’re at war with this virus,” he says. Abraar Karan, an internal medicine physician at the Brigham and Women’s Hospital of Harvard Medical School in Massachusetts.
Shashank Heda, MD
(For COVIDRxExchange, a global nonprofit initiative working since April 2020 for disseminating expertise and insight on management of COVID).
Join our thousands of medical experts on Slack https://join.slack.com/t/covidrxexchange/shared_invite/zt-le49a2h0-QUsrvUe_5xsdBwgWvEQxrQ