The Delta variant caused a fresh wave of Covid-19 infections worldwide, aggravating the global public health catastrophe. The currently available Covid-19 vaccines are effective against the Delta variant, which prompted researchers to evaluate whether booster doses for vaccinated people are necessary and when they should be given. The objective of the booster dose is to extend vaccine efficacy in people already administered with primary vaccination. However, this decision should be taken after careful analysis of the necessity of boosters and their timing. India, however, should refrain from administering booster doses to its population until further studies are done to show its utility.
With the recurring waves of Covid-19, several countries have advocated booster doses. On August 4, 2021, the World Health Organisation (WHO) called for a moratorium on boosters until September. The WHO objected to high-income nations giving their citizens the third round of shots when low-and middle-income countries struggled to provide their first. Around the time it announced the moratorium, 58 per cent of the population had received at least one dose of vaccination in high-income countries. In contrast, the numbers stood at only 1.3 per cent for the low-and middle-income countries.
Few studies were recently undertaken to understand the efficacy of booster doses. Studies in Israel showed improvements in the antibody levels in people administered with all three shots of Pfizer-BioNTech. A study published in August 2021 showed that administration of the third dose of the Covid vaccine (Pfizer-Moderna) to organ transplantation recipients showed better immune response than patients who had only two doses of vaccine, and none of these patients reported any cases of Covid-19.
In September 2021, another study on organ transplant recipients, where one group of people was administered the third dose of Covid-19 vaccine (Moderna) while the other group was placebo, showed patients who received the third dose had significantly higher immunogenicity than the patients with placebo. It showed that receiving a booster dose could protect the immunocompromised people than just standard two doses. Countries like the United Kingdom, Israel, Russia, the United Arab Emirates, and others have started administering booster doses to their populations. Israel has made booster doses mandatory for a complete Covid passport.
With high-income countries advocating booster doses, there are a few questions we need to ask. First, who needs the booster dosage? According to the WHO, the additional or booster dosage should be administered to people with weakened immune systems. This recommendation comes after a four-day conference of the Strategic Advisory Group of Experts (SAGE) on immunisation. The final report is due in December 2021. The US CDC (Centers for Disease Control and Prevention) list of those who can get the booster includes patients suffering from cancers or HIV, individuals who have had organ transplantation, and those receiving immunosuppressive drugs.
India, however, still needs to assess if it wants to consider giving booster doses to its citizens. The Union Health Ministry has currently adopted the "wait-and-watch" policy. Balram Bhargava, Director General of the Indian Council of Medical Research (ICMR), has maintained that India's top priority is acquiring two doses. India's indigenous vaccine, Bharat Biotech's Covaxin, is currently undergoing trials for booster doses and the results are yet to be published.
A key factor to consider about booster dose for India is the domestic requirement. India recently reached the milestone of vaccinating 100 crore doses in October 2021. According to the Union government, two-thirds of the adult population (66 per cent) was administered one dose, 99 per cent of healthcare workers with at least one dose and 85 per cent with both by September.
India has targeted vaccinating its entire adult population by December 31, 2021. As of October 31, 2021, the US had fully vaccinated 58 per cent of its people, and the UK approximately 80 per cent, which means that developed countries like the US and UK only advocated a booster dose after fully vaccinating at least half of their populations. India, on the other hand, has successfully fully vaccinated only 21.9 per cent of its population. It has currently administered 106.3 crore doses of Covid-19 vaccination, which accounts for a little over half of 187 crore doses it aims to administer by the end of 2021. This indicates that for it to go from 20 per cent to 100 per cent of fully vaccinated adults, India must do what it has done over the past nine months in two months. With such an arduous task at hand, going forward with a parallel administration of booster doses may not be a feasible option at the moment.
Other factors need to be considered about booster dosages as well. Vaccination drive for kids in India aged between 2-18 years old hasn't started yet. An expert team reviewing vaccines has recommended Covaxin as one of the two vaccines for kids as young as two years. The Drug Controller General of India (DCGI) has approved emergency use in minors. However, as of now, Covaxin has not been able to scale up its production. Covaxin's goal in May was to deliver an average of 10 crore monthly doses from June to December. A month later, this goal was brought down by 20 per cent, and as of September, its monthly capacity was significantly lower. With Covishield being the lead vaccine being administered in India, Covaxin needs to scale up its production if India wants to inoculate the majority of the adult population by December 2021, thus ensuring that the current vaccination drive continues smoothly. With such instability in the supply of Covaxin, parallel administration of booster doses is not a sound move.
There has also been an ongoing conversation on whether healthcare workers (HCWs) should be given a booster dose. Healthcare workers were the first to be prioritised when the vaccination drive kick-started in India in January 2021. There is increasing fear among healthcare workers regarding waning antibodies and the possibility of infection. Fortis Healthcare released an evidence-based study in June 2021, which showed that 92 per cent of the fully vaccinated HCWs showed mild symptoms of Covid-19 and did not require any hospitalisation. Most of the current studies on booster doses are focused on restoring the antibodies against the Covid-19 virus and extending the immunity against the disease. However, we will have to wait for studies to conclusively show that these antibodies can protect against the virus for an extended period.
Several vaccination specialists believe the research so far only supports the necessity for booster doses in older adults and people with weakened immune systems. Booster doses are now being administered in several developed countries. However, this administration only began after nearly half of their population was fully vaccinated. India, however, should not consider booster doses as of now.
India should focus on vaccinating its adult population by December 2021 since we are presently at the final quarter of this year. We also need to prioritise vaccinating our kids. Though the concept of the booster vaccine is welcome, the decision for its administration should be strictly evidence-based. If the government were to consider vaccinating the people with booster doses after a thorough study, it should be prioritised, as per the CDC guidelines. Immunocompromised people, healthcare workers, and the elderly should be given priority as they are at a higher risk of infection.
(The writer is a Research Analyst at The Takshashila Institution, Bengaluru, and has an MSc in Stem Cells and Regenerative Medicine from Manipal University)
Disclaimer: The views expressed above are the author's own. They do not necessarily reflect the views of DH.
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