Coronavirus Delta variant: How effective are COVID-19 vaccines against the newest Delta variant?

The pandemic, way into its second year has shown no signs of slowing down and mutations of the coronavirus have been suspected to have fueled the rise in case. The B.1.617.2 variant of coronavirus, also referred to as the Delta variant is categorized as a Variant of Concern (VoC) and said to have originated in India. It is also one of the primary factors which led to the surge in cases recorded during the second wave, and now, starting to spread around the world as well.

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The rise of the Delta variant which is said to be super infectious and contagious, has made authorities press for speedier vaccination for the masses, including the younger ones. Even so, there have been a number of cases wherein people have contracted the virus but suffered from fewer complications with the vaccine. But how exactly effective are the COVID-19 vaccines right now? Will vaccination fully protect us from more variants of concern wreaking havoc?

All you need to know about the Delta+ COVID variant

If yes, what protection do they offer against infection, hospitalization and mortality? We brief you on the same...

Efficacy and effectiveness are relative terms that are used to measure how good a vaccine is. While efficacy is monitored under clinical settings, effectiveness helps us get the real-world data, how potentially preventive or protective a vaccine would be, in the real world.

For example, a 94% efficacy rate would mean that vaccinated people would have a 94% lower risk of developing the illness (symptoms) as compared to those who get COVID without being vaccinated.

The effectiveness of a vaccine, or COVID vaccine particularly tells us how workable it is in respect to outcomes like symptomatic illness, hospitalization and death rates. What we have to remember, however, is that the rates and the effectiveness can greatly differ based on how the virus mutates or behaves.

The vaccines which we have with us right now were clinically studied and developed in respect to the Alpha variant of the coronavirus, which is its original form that majorly caused the first wave of the pandemic across the world, in 2020.

The Delta variant and other variants of concerns haven't yet been fully tested under laboratory settings to determine how good or bad vaccines are against them. There have also been concerns which state that the newer variants of the virus contain properties that allow them to escape immune defences easily, and may surpass vaccine driven protection as well. This is one of the reasons why many believe there's been a rise in breakthrough infections post vaccination.

However, even with a rise in people contracting COVID-19 after being vaccinated, it has been observed that the jabs are well-effective against severe outcomes and complications, linked to the nasty virulent strains of the virus.

Both hospitalization and mortality are critical standards through which a pandemic's spread is measured. A lower hospitalization rate lessens the load on healthcare resources as well. While we continue to gain more insights on experimental vaccines, it has been greatly observed that vaccines, when well-administered offer a good level of protection against most concerning variants and cut down the need for hospitalization. What has also been reassuring is that vaccinated people may also have quicker recovery timelines and fewer symptoms.

For example, observations have found that the two most talked-about vaccines, the Pfizer-BioNtech mRNA vaccine and the Oxford-Astrazeneca vaccine offer similar rates of protection. While Pfizer's jab offers 94% effectiveness against Delta variant and hospitalization, the Oxford jab (sold in India as Covishield) offers 71% and 92% relative protection with single and double doses, respectively.

Do note that these outcomes have been found to be applicable for those who have been fully vaccinated (i.e. 14 days have passed after they got the second dose).

There's promising evidence right now that vaccination, even if not completely capable of evading the infection risk, promises good outcomes in curbing the mortality rate. Early studies have found that Covaxin, India's homegrown vaccine is over 100% effective in taming the mortality rate. The rates have also been observed in the lesser symptoms and deaths ruled amongst senior citizens and healthcare workers, who were amongst the first groups to get vaccinated in India.

However, we still need more data to confirm these findings.

Vaccines are nothing short of a good protective shield against COVID-infection risk. While they may not offer complete protection against the contagion, they can greatly cut up severity and mortality rates right now. Experts have also suggested that the faster we reach herd immunity and speed up vaccination, the better we would be able to tame the spread of future variants as well.

COVID-appropriate measures, securing full vaccination and practising basic measures still remains important to fight the virus from the root.