Covid-19 vaccine: A potent addition to our armamentarium?

Since January 2020, the world has woken up to the reality that a small infectious agent can make the 'mighty human' tremble with fear like honeybees create fear in an elephant's mind!

Governments and health organisations while working 24/7 are looking up at the sky for the magic bullet to appear – the corona vaccine! Though various novel treatments are being attempted, most are pinning their hopes on a new vaccine.

This is because everyone realises that Covid-19 is not going to be a one season pandemic. It will dig its heels deep enough to trouble us, year after year, as did the influenza virus in 1918.

Globally, academia and biotechnology companies race against time to develop and mass-produce an effective and safe Covid-19 vaccine.

A vaccine cannot be released into the market without undergoing stringent testing, first at the laboratory and then on humans through a series of steps called phases of clinical trials. There are four phases which test safety, side-effects, effectiveness and watching out for any adverse events.

Fast-tracking is possible only in developing a vaccine, but human trials have clinical and ethical issues that have to be carefully considered. Such a lengthy process means that the vaccine cannot be used for the present pandemic but needs to be stocked in sufficient quantity by governments for possible future outbreaks.

The costs involved in the development and the long time it may take for return on investment deter many commercial companies to venture into this space. It is indeed a matter of pride that among those willing to take the plunge are six Indian companies, including two from Hyderabad.

The availability of a vaccine, even in the later part of the year or early next year, cannot be construed as the last frontier. The deployment and utilization of the vaccine is the most important challenge.

A billion plus individuals cannot be immunised at will. So, who will be given the vaccine as a priority, how much will it cost, will those for whom it is intended accept the vaccine, will it protect the older population who are most at risk of death benefit as much as the young are all questions that need to be answered.

Let me take the example of the influenza (flu) vaccine to illustrate these points. The World Health Organisation (WHO) estimates that between 3-5 million severe illness and between 2,90,000 – 6,50,000 deaths occur every year due to influenza.

During the 20th century three major pandemics of influenza were reported in 1918, 1957 and 1968 and all three were different strains of the virus. Most recently in 2009, the world saw an outbreak of swine flu in humans from a virus infecting pigs (H1N1 strain). India was also badly affected. 27,236 cases were reported in India in 2009 with 981 deaths.

The next year (2010), the country saw 20,604 cases with 1,763 deaths. Since then, cases of H1N1 flu have been reported every year. Except in 2016, all the other years saw between 28,798 to 42,592 cases till 2019 and between 1218 to 2990 deaths. 2017 saw two peaks and a large number of deaths, interestingly in Gujarat, Maharashtra, Rajasthan and Madhya Pradesh like in the present pandemic.

This is data collected and reported by the Integrated Disease Surveillance Program in India as H1N1 flu has to be reported to the government. Unfortunately, a majority of the private sector facilities do not report as most of the flu infections are not laboratory confirmed. Therefore, even the numbers above underestimate the actual numbers.

Just like Covid-19, flu also causes significantly higher deaths among the elderly, those with co-existing conditions like diabetes and hypertension and those with other diseases which affect the human immune system.

Like Covid-19, influenza is highly contagious, and risk of infection is increased by close contact with other infected individuals. However, unlike Covid-19, influenza has a cost-effective vaccine to protect those at risk of serious complications including death.

With efforts from WHO and Global Alliance for Vaccines and Immunization (GAVI), the global influenza vaccine production has been ramped up to 6.4 billion doses. However, despite the pandemic of influenza in 2009 and 2010 the number of influenza vaccine doses distributed was only 1.1 per 100,000 population in India. In 2011 it increased more than 400% compared to 2008.

Influenza vaccine is available for more than 60 years now, but the uptake has not been commensurate with the recommendation for influenza immunisation.

The influenza vaccine has to be given every year to these high-risk groups. In India, though there is no national seasonal flu policy, the government of India's National Centre for Disease Control (NCDC) recommends it for healthcare workers, pregnant women, children aged 6 months to 8 years of age and individuals with suppressed immunity.

Despite these recommendations and the high mortality in 2009 and 2010, the uptake even by frontline healthcare workers in India immediately after the pandemic was abysmally low. The vaccine uptake was 11% in tertiary care hospitals, including among doctors. India imported 1.5 million vaccine doses to immediately immunise healthcare and emergency service personnel and the vaccine was provided to all States.

Barring a few States the uptake was disappointing and a large quantity of the vaccine including that which was manufactured by Indian companies had to be destroyed because of lack of demand. This was within a year of the pandemic and with a large number of deaths already reported by then. In fact, the number of cases and deaths were higher than what has been currently reported in the Covid-19 outbreak in India till date.

Flu continues to affect millions and kill thousands. To combat flu, the vaccine is only one cog in the wheel of public health strategies. The WHO clearly states that apart from vaccination and antiviral medicines, personal protective measures are critical.

All this sounds very familiar with the media attention to Covid-19 today but, remember that these tenets are not from 2020 but since the last century. It is only the perceptions and awareness of people that have changed. Let us hope that this heightened awareness actually translates into positive actions.

So, waiting for a vaccine to sort out the conflagration should not be like waiting for the fire engine to put out the fire. The vaccine 'fire engine' is only one of the tools that can be deployed in our armamentarium to fight Covid-19.

Better still, it is not adding fuel to the fire! Therefore, we all have to assiduously follow the rule of 'Is' to fight the battle and not wait for the 'fire engine' to put out the fire.

(The writer is Director, Indian Institute of Public Health, Hyderabad, Public Health Foundation of India, & Professor, London School of Hygiene & Tropical Medicine, London, UK)