DOES VACCINATION SHOW PROMISE AGAINST VARIANTS?

SARS- CoV-2 has wreaked havoc all around the world with the pandemic taking lives of over 4.5 million people around the globe. Symptoms vary from common fever to aggravated pneumonia-like symptoms.

 The single stranded RNA virus has spike proteins that attach to the cells with ACE-2 receptors and the genetic material is endocytosed. The virus undergoes replication, translation and is assembled in the cell cytoplasm. Major mutations were observed in the spike protein leading to formation of multiple variants. The predominant ones are Alpha (B.1.1.7) and Delta (B.1.617.2, AY.1, AY.2, AY.3)

Vaccination has played a major role in effective containment of the infection. Studies conducted to understand the effectiveness of vaccination against SARS CoV-2 variants show a marked decrease in the infectivity of the virus. Comparisons between Pfizer-BioNtech and AstraZeneca Covishield show that after first dose of vaccination, effectiveness against delta variant was lower when compared to the Alpha variant. After the second dose, no marked difference was observed in the effectiveness against both Delta and Alpha variant. The study confirms that two doses of vaccines from both AstraZeneca and Pfizer show protection against the Delta variant increasing the importance of Vaccination.

Another analysis performed recently by the Indian Council of Medical Research shows that heterologous vaccination of both Covishield and BBV152 (Covaxin) showed significantly higher antibody response against Alpha and Delta variants. This study shows increased immune response upon using vaccine cocktail.

Although vaccination has been proven to increase immunogenicity, it does not guarantee complete protection. Positive cases have been reported despite two doses of vaccine. Nevertheless, there is no cause for panic since research on cases of COVID post vaccination show milder infection rates with higher oxygen stability.

The importance of vaccination cannot be reiterated enough. Therefore, it stands unsaid that vaccination is of utmost necessity to protect ourselves against virulence of the virus. Although further research must be done to affirm the effectiveness of the vaccines against the upcoming Delta plus variant.

SOURCES:

1. Lopez Bernal J, Andrews N, Gower C, et al. Effectiveness of Covid-19 vaccines against the B.1.617.2 (delta) variant. N Engl J Med 2021;385:585-594.
2. Kant R, Dwivedi G, Zaman K, et al. Serendipitous COVID-19 Vaccine-Mix in Uttar Pradesh, India: Safety and Immunogenicity Assessment of a Heterologous Regime. medRxiv; 2021. DOI: 10.1101/2021.08.06.21261716.
3. Sashindran VK, Rajesh K, et al. COVID in Post Vaccinated individuals- Beacon of Light. medRxiv 2021. doi: https://doi.org/10.1101/2021.06.18.21258796