According to the new updated study on COVID-19 Vaccines by Global Industry Analysts (GIA), approximately 53% of world population will be fully vaccinated by the end of the year 2021. This figure is expected to increase to 81% by the year 2022. The rapid vaccination programmes launched around the world has led to millions of people being fully vaccinated, particularly in developed nations. With the rise in vaccination rates, measures designed to limit the spread of Covid-19 like mask mandates and capacity limits have been relaxed. The subsequent relaxation strengthened consumer confidence and allowed economic activity to return to normalcy. However, with the Covid-19 virus rapidly mutating, new variants have emerged in many parts of the world, posing a threat of potential future waves. These new variants are more deadly than the original virus, more easily transmissible and can impact the effectiveness of vaccines. Viruses naturally change over time through the process of mutation. Among the thousands of variants currently circulating around the world, Delta (B.1.617.2), Alpha (B.1.1.7), Beta (B.1.351), and Gamma (P.1) have emerged as variants of concern, and the reason behind subsequent spike in infections. These variants were first identified in India, the UK, South Africa, and Brazil respectively. The high number of Covid-19 cases also increases the risk of virus mutations, leading to the emergence of new variants. The spread of the Delta variant has forced some countries to step up their vaccination campaigns and bring back curbs on businesses, activity and travel.

Messenger RNA (mRNA)-based Covid-19 vaccine from Moderna and Pfizer stand out not only as frontrunners but also as being more protective against newer variants. mRNA vaccine although never been licensed for use in humans before, is now being approved in the fight against COVID-19 largely because of the speed at which these vaccines can be produced. mRNA vaccines work by introducing a part of mRNA that reacts to the viral protein. It accelerates production of antibodies and trains the immune system to recognize the virus in the future, thereby offering protection. Beyond Covid-19, mRNA vaccines also hold promise for combatting cancer and infectious diseases, such as malaria and flu. Early animal testing has shown that mRNA vaccines demonstrates efficacy against viruses such as influenza, Zika and rabies. mRNA-based vaccine technology is the most preferred platform for developing a vaccine for COVID-19 in part because it offers some advantages in the pace of development, high potency, and potential for low-cost manufacture.

After a sharp drop in cases throughout the first half of the year, cases began to spike again as the Delta variant took over. This variant now accounts for the vast majority of new infections. To a certain extent, current vaccines have been shown to work against mutants. They provide protection against developing severe disease, hospitalization and death due to the variants. This in turn has prompted vaccine makers to pursue booster shots. The leading vaccine makers, Pfizer-BioNTech, Moderna and AstraZeneca announced plans to pursue development of booster shots to address the emerging threat of new virus variants. The booster shot will be essential to keep the immune system to the optimum level. A number of wealthy countries like the US, Germany and Israel are considering booster shots to increase protection against Covid-19. Germany is expected to roll out booster shots in September to vulnerable individuals such as pensioners and people with weak immune systems. mRNA-vaccines from Pfizer/BioNTech and Moderna will be offered as booster shots, regardless of the vaccine administered previously.

In India, Bharat Biotech, the makers of Covaxin, received regulator`s approval for conducting trials for a third shot that will be administered as a booster dose. While a booster dose is typically an exact replica of the initial vaccine, it can also be tweaked. Moderna, AstraZeneca, Pfizer are working on variant-specific booster shots. Recently, Moderna announced positive initial data from its ongoing phase 2 study. The data revealed that the booster dose increased neutralizing antibody responses against the original virus as well as B.1.351 and P.1, in previously vaccinated individuals. Studies suggest that a third dose can boost also antibodies in the blood of some immunocompromised patients. Despite being fully vaccinated, people with weak immune systems may not have strong defense against new variants. With Covid-19 cases on the rise, millions of cancer patients undergoing treatment, organ transplant recipients and others are still susceptible to severe Covid-19. In response, Israel is administering third doses of the Pfizer vaccine to immunocompromised people, including those who have had heart, lung, kidney or liver transplants and cancer patients receiving chemotherapy.

Despite the fewer cases of Covid-19 in pediatric populations and adolescents, vaccinating young children and teenagers is crucial to significantly slow the spread of Covid-19 and achieve herd immunity. Young children and particularly adolescents can play a significant role in coronavirus transmission. Studies are underway evaluating vaccine safety for younger children in various countries. Vaccination will allow children to return to in-person teaching safely and ease the burden on parents. Pfizer vaccine is currently authorized for ages 12 and older in the US, Australia, Mexico, Brazil, Chile, Philippines, Japan, New Zealand, Dubai, UK, and few EU countries. Moderna is seeking approval for teens as young as 12 in the US, Canada and EU. Another mRNA vaccine maker, Novavax is expected to start clinical trials evaluating the efficacy of its vaccine on children, while China has already approved Sinovac`s vaccine for emergency use in children as young as three. India vaccine makers such as Bharat Biotech, Serum Institute of India and Zydus Cadila have either initiated clinical trials or are in the process of doing so for their Covid-19 vaccine for children. Young teenagers with chronic health problems such as diabetes, severe asthma, obesity and chronic cardiac disease; compromised immune systems, and those who have organ transplants are more likely to be at risk of severe Covid-19 disease. Australia and the UK authorized the use of Pfizer`s Covid-19 vaccine for vulnerable children aged between 12 and 15 years old, as cases of the highly contagious Delta variant rise sharply. So far, data from clinical trials suggest that the Covid-19 vaccines are safe in adolescents. With this in mind, Pfizer and Moderna have moved on to carrying out clinical trials in children as young as 5 years old. The vaccination of vulnerable populations will undoubtedly have a positive impact on the pandemic control and serve as a catalyst to promote rapid economic recovery.