An unethical normal?

When India started administering 'precautionary' doses of COVID-19 vaccines to those 'fully vaccinated', it not only joined the league of booster-haves but also stepped into a much-discussed dilemma — medical and ethical. The possibility of repeated booster shots with the emergence of new variants can become integral to our pandemic containment strategy and also deepen inequalities, experts said.

Booster shots have raised concerns about vaccine-inequity ever since developed countries started rolling them out in 2021. There have also been doubts over their ability to provide long-term immunity. Yet, they may soon become the new normal.

Prime Minister Narendra Modi last Christmas announced additional vaccine doses for healthcare workers; they were rolled out in January 2022. Others too have now become eligible, provided their second dose was administered nine months ago.

The World Health Organization (WHO), in its interim statement on COVID-19 vaccines in the backdrop of an omicron-triggered wave had said January 11: A vaccination strategy based on repeated booster doses of the original vaccine composition is unlikely to be appropriate or sustainable.

Fast forward to March 8, the global health body shifted gears and stated how it "strongly supports urgent and broad access to current COVID-19 vaccines for primary series and booster doses".

Concerns about vaccine inequity and capability of boosters providing long-term immunity remain.

Still, they may soon become the new normal. Does that mean our immunity has waned? Shiv Pillai, professor of medicine, health sciences and technology at Harvard Medical School, argued that not only has immunity waned, but also, we are now dealing with something that's different from the virus against which the vaccines were initially developed. He said:

"BA.1 and BA.2 have changed quite dramatically in a couple of parts of the molecule, the spike protein specifically. If around 25 per cent of our antibodies are still effective and 75 per cent are not, we need a lot of those 25 per cent, and a booster increases that number."

Boosters provide short-term protection from infection, data on vaccine efficacy suggested. There first needs to be a consensus on what the goal of vaccination and boosting is, according to experts.

Everyone agrees that protection against hospitalisation is needed, Peter Hotez, who co-chairs the Lancet Commission on COVID-19 Vaccines and Therapeutics Task Force, told Down to Earth. "But there is a disagreement as to whether protection against an emergency room visit, long-COVID or infection is needed. I'm not advocating continuous boosting, but a single boost of a different vaccine will hopefully give us durable protection," he added.

Attempts are underway to develop a variant-neutral vaccine, said Pillai. Here, what you're protecting against is going to be common to all coronaviruses. They will provide protection, but the really elite level of protection to prevent infection comes from targeting a certain part of the molecule that is specific for that virus and its spike protein, Pillai explained.

Periodicity, infrastructure challenges

The frequency at which these boosters need to be administered remains unclear. A blanket booster rollout for everyone every six months is unnecessary, said Shahid Jameel, virologist and former head of the Indian SARS-CoV-2 Genomics Consortium.

One booster is probably needed for the comorbid population, but a majority of the population already has hybrid immunity — infection and primary vaccination — which is turning out to be the best, the expert added.

Has regular boosting ever worked against a viral infection? "This is the first pandemic we are trying to curb with a vaccine," Jameel told DTE. The closest comparison one comes to is influenza, for which you need a vaccine every year and even those are recommended for the elderly age group. The Ebola and SARS-CoV-1 outbreaks were controlled largely with isolation, as no vaccines were available in time.

The existing vaccines will have to be updated if regular boosting becomes the norm. Several companies are developing new versions of vaccines that represent the newer strains, but mRNA vaccines — such as those from Pfizer/BioNtech and Moderna — are the easiest to update, Nigel Stevenson, assistant professor of immunology, Trinity College Dublin explained.

This will be most useful if the virus mutates into a more deadly strain, he added. "Being able to immediately mobilise the mRNA vaccine pipeline to quickly generate a vaccine against a more dangerous strain will be essential."

The companies are poised to kick-start the process, if required, the expert said.

The influenza vaccine offers a hint, according to Priya Sampathkumar, infectious disease specialist at Mayo Clinic in Rochester, Minnesota. "The flu virus also keeps changing, like the novel coronavirus." The WHO is tasked with coordinating the collection of samples of the flu virus across the world.

A group of scientists then collaborate and decide which of the circulating strains could become dominant and target a vaccine towards that, she explained, adding that it's a lot of guesswork. "Maybe we can have something similar for COVID-19 where international corporations will need to come up with what strains to include in the vaccines."

Deepening inequality

The country's entire adult population, except those above 60 years of age and healthcare workers, have to pay for a booster dose. The government has borne a huge financial burden due to the COVID-19 pandemic but it needs to be cautious in allowing the vaccine to be privatised, said Leena Menghaney, a lawyer working on public health and access issues.

This is what the pharmaceutical industry has wanted all along — to boost sales of the COVID-19 vaccines in the lucrative private sector, she added. "An attempt was made last year when those under 45 years of age were asked to get vaccinated at their own cost, the Supreme Court had to step in."

This is the people's vaccine; government funding has gone into it so the booster dose must be available free of cost to all those eligible, the lawyer added.

The financial burden has to be offset by the fact that many people can't afford to pay for the booster and will most likely go without it, Menghaney noted.

A significant share of the vaccine doses manufactured globally have been diverted to high-income countries to provide booster shots even as over 80 per cent of the population in Africa remains unvaccinated. DTE

Views expressed are personal