Coronavirus: Will you need a COVID-19 vaccine every year?

The successful development and launch of coronavirus vaccines around the world helped us breathe a sigh of relief. Although over a period of time, we have come to realise the prevalence of breakthrough infections, the available jabs have proved effective against the SARs-COV-2 virus and have minimized the risk of hospitalization and deaths to a great extent. However, none of the COVID-19 vaccines are 100 percent effective. Given the emergence of new variants, which are not only transmissible, but have the ability to escape vaccine-induced immunity, one may need another dose to ramp up the immune response to protect oneself from getting infected after a set period. But while there are no conclusive answers to whether or not we'll need an annual COVID shot like the flu, here's all you need to know now.

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With new emerging variants comes new challenges. While the Delta variant was one of the deadliest of its kind, causing severe damage to the lungs, leading to severe, distressing symptoms and in the worst case scenario claiming many lives, the Omicron, which is comparatively more milder, is said to be highly transmissible, while possessing the ability to evade natural and vaccine-induced immunity. This is because the latest variant of concern is said to have over 50 mutations, which gives it the ability to spread faster and dodge the immune responses.

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That said, the greatest challenge currently is the effectiveness of the current vaccine against the mutations of the virus. It is likely that the vaccine's effectiveness and efficacy may not be the same as earlier. A high efficacy rate of a COVID-19 vaccine does not mean that it will have a high level of effectiveness in the real world. Most of the time, the effectiveness of the vaccine differs due to variables taking place in the real world.

Furthermore, the coronavirus strain is continuously mutating and the same vaccine may not be effective on all the mutant variants. Therefore, experts have recommended either updating the existing COVID vaccines or developing variant-specific vaccines in the future.

The onset of the Omicron variant raised concerns around the world. Experts found that the variant contained several mutations which enabled it to escape immunity from both a natural infection and the vaccines.

In light of such findings, doctors and medical professionals suggested updating the available COVID-19 vaccines to match the new variants.

Previously, the WHO technical body had said that the current COVID-19 vaccines may need to be reworked to ensure they are effective against Omicron and future variants of the coronavirus.

"The composition of current COVID vaccines may need to be updated to ensure that vaccines continue to provide WHO-recommended levels of protection against infection and disease by VOCs, including Omicron and future variants," they said.

They further added, "COVID-19 vaccines need to... elicit immune responses that are broad, strong and long-lasting in order to reduce the need for successive booster doses."

The global health agency believes that repeated booster doses of the original vaccine composition is unlikely to be appropriate or sustainable."

Another reason why COVID-19 vaccines could become a regular affair is the possibility of waning immunity.

Following the initial two vaccine doses, protection provided by the vaccines may wane over time. Given the sudden rise in the number of COVID-19 cases and the prevalence of breakthrough infections, experts have come to believe that vaccine-induced immunity diminishes over time.

According to the World Health Organization (WHO), "Emerging data consistently show a decline in vaccine effectiveness against SARS-CoV2 infection and COVID-19 with time since vaccination, and more significant decline in older adults."

COVID vaccine boosters are an extension of COVID-19 vaccines, which help re-expose the body's immune system to the immunizing antigen, the memory of which (after the previous two doses) may have waned over time.

Although the WHO is of the opinion that booster shots are not a sustainable vaccine strategy, many countries including India have begun administering the third COVID shot. While immunity from COVID vaccines may dwindle over time, experts believe that we may need to boost our immune system frequently, which could be in the intervals of months or even annually. However, there is no conclusive evidence to suggest the same.

Many pharma giants are looking forward to developing Omicron-specific vaccines, which will specifically target the concerned variant.

In the US, Pfizer BioNtech and Moderna have both announced that they have initiated clinical trials of Omicron-specific vaccines. Similarly, Pune-based Gennova Biopharmaceuticals is all set to develop India's first homegrown mRNA, Omicron-specific COVID vaccine.

But while Omicron-specific vaccines are the need of the hour, many scientists and experts have come to the fore presenting a completely different idea, suggesting that new specimens and strains of the virus emerge time and again and that it is extremely difficult to keep up with it. By the time the vaccine actually launches, either the infection rate may have died down or a new variant could be in play.