In these dark times, we are clutching to a hope being propagated by the powerful around us that vaccination of majority adults (~70–80%) will stop the SARS CoV-2 pandemic. Scratch the surface and we see their selfish motives. Politicians want to get rid of the viral stain on their record and lull people back to dream worlds of nationalistic pride and social hate. Capitalists want their labour behind their machines and laptops to restart the profit cycle. Religious leaders who want crowds back and with them their adulation and wallets. Social elders want social gatherings back with full plomp to reinforce their social standing.
The key to pulling back the curtain of this myth is to ask three obvious questions which have been staring at us
- Why were other vaccine platforms (mRNA, viral vector) preferred over the “Whole Inactivated Virus” platform?
SARS-CoV-2 has four proteins : the E and M proteins, which form the viral envelope; the N protein which binds to the virus’s RNA genome; and the S protein, which binds to human receptors. Our immune system fights against the virus by releasing antibodies specific to the above proteins. Studies showed antibodies against the N-protein delayed virus clearance while increasing disease severity. This has been attributed to the ADE (AntiBody Enhancement) effect which has been well documented in similar viruses like SARS CoV-1, MERS, FIPV. Simply put, some antibodies bind to the virus but instead of neutralizing them, they work in the opposite manner and ensure virus uptake into cells which otherwise would not have been infected.
In fact, globally scientists learnt from their debacle in developing vaccines to SARS-CoV-1, MERS and Dengue viruses while deciding to target only the spike protein in the current coronavirus. (Not that this is a foolproof strategy. More on it later). A “Whole Inactivated Virus” vaccine (or an actual infection) may generate antibodies to all viral proteins thereby increasing risk of ADE in an actual infection.
2. Why was Plasma therapy discontinued?
The above discussion makes it pretty obvious why plasma therapy was doomed to fail. Infected people create both neutralizing and non-neutralizing titres of antibodies with different proportions for each donor patient. This plasma had a neutral to negative outcome (ADE effect) for recipients based on their physiology and pathology.
3. Will current vaccines work against new variants?
Now, we come to the Big Daddy of all questions. We are being fed a linear narrative that current vaccines which were 80–95% effective against original Wuhan strain will also be effective against newer South African/ Brazilian/ Double Mutant strains albeit to a lesser degree (66–80%). The truth is more nuanced.
Firstly, if the variants are significantly different from the strains used in vaccine development, then we risk OAS (Original Antigenic Sin) in case of vaccination. Simply put, prior memory of fighting the virus/ viral fragments induced by the vaccine will severely limit our immune system’s capability to adapt to the new strain and contain it.
Secondly, relatively lower levels of neutralizing antibodies, even to the spike protein may not fight the virus but instead go the ADE way increasing disease severity. Already, media reports suggest antibody levels required to neutralize Double Mutant, Brazilian and African strains are much higher and vaccinated individuals are also generating lower levels of antibodies on exposure to these strains.
Thirdly, antibody levels wane with time. Current vaccines appear to be providing protection with high antibody levels. The risk of ADE for lower levels of antibodies remains unknown.
Finally, vaccines (and plasma) themselves may be triggering and accelerating mutations. Basic fact of Covid: Transmission stage is 0–5 days from viral inoculation whereas immune response kicks in only later. While selection pressure exerted by the immune response may have led to mutations previously, they would not have transmitted in scale. It is the presence of antibodies before infection which are pushing the virus to adapt from the start and enabling spread during the asymptomatic phase of the disease.
Therefore, the main worry is one day when coronavirus will mutate to the point that the antibodies generated by the current vaccines become non-neutralizing and instead facilitate their uptake.
Hope this cascade of bad news has shaken you out of the vaccine dream sold by our powers to be. If you still say these are just conjectures and are not supported by facts, please check out the Twitter handle: c400_t
References
- Antibody-dependent enhancement and SARS-CoV-2 vaccines and therapies (Wen Shi Lee, Adam K. Wheatley, Stephen J. Kent & Brandon J. DeKosky)
- Antibody-dependent enhancement (ADE) of SARS-CoV-2 infection in recovered COVID-19 patients: studies based on cellular and structural biology analysis (Fan Wu et al)
- An infectivity-enhancing site on the SARS-CoV-2 spike protein targeted by antibodies (Yafei Liu et al)
- Antibody-dependent enhancement of coronavirus (Jieqi Wen et al)
- Role of antibody-dependent enhancement (ADE) in the virulence of SARS-CoV-2 and its mitigation strategies for the development of vaccines and immunotherapies to counter COVID-19 (Kumaragurubaran Karthik et al)
- Contribution of antibody-dependent enhancement to the pathogenesis of coronavirus infections (Yu. A. Desheva et al)
- https://science.thewire.in/the-sciences/how-novel-coronavirus-variants-could-complicate-our-covid-19-vaccination-drive/
- Immunological and physiopathological approach of COVID-19 in pregnancy (Raquel Ferrer-Oliveras et al)
- https://coronavirus.medium.com/why-vaccine-boosters-may-not-solve-the-mutating-coronavirus-problem-f35fd6fdbfc1
- https://blogs.sciencemag.org/pipeline/archives/2020/12/18/antibody-dependent-enhancement
- SARS-CoV-2 evolution during treatment of chronic infection (Steven A. Kemp et al)
- Viral targets for vaccines against COVID-19 (Lianpan Dai & George F. Gao)
- Original Antigenic Sin: the Downside of Immunological Memory and Implications for COVID-19 (Eric L. Brown and Heather T. Essigmann)