A New Covid-19 Mantra? 'Nobody Is Safe until Everybody Is Fed'

A common refrain in recent months around Covid-19 has been that “nobody is safe until everybody is safe,” referring to the importance of developing an effective vaccine for the coronavirus and ensuring its equitable distribution. At present, hundreds of separate vaccine candidates are being developed and dozens are now in clinical trials.

Pfizer, Moderna, and AstraZeneca have each recently announced (at the time of publication) that their vaccines have proven highly effective in late-stage trials. These are major breakthroughs in the first act in what will surely be the world’s greatest inoculation campaign in history. While vaccines are now imminent, questions remain around how they will be distributed, who will get access to the first doses, and when sufficient quantities will be available for the masses.

Across the developing world there may be something else we need to ask ourselves: will people be healthy enough for the vaccine to work properly? Evidence from previous inoculation campaigns suggest that vaccine efficacy may depend, at least in part, on nutritional status, a condition that, in a terrible irony, is deteriorating for many vulnerable people in the face of Covid-19. 

A Food Security Crisis

Each month that passes without a vaccine, the economic impacts of lockdown measures and virus transmission continue to drive food insecurity around the planet. Since the pandemic was declared on March 11 of this year, this global health emergency has quickly become a global food security crisis.

The United Nations World Food Program projects that Covid-19 could cause the number of people facing crisis levels of hunger to nearly double by the end of the year, due in large part to losses in income. Four countries—Yemen, Syria, South Sudan, and Burkina Faso—are at the brink of famine due to a toxic blend of conflict, climate extremes, and Covid-19.

It is expected that the global economy will contract by more than 5 percent this year, leading to the loss of some 500 million jobs, many in the informal economy. Countries that rely on commodity exports like oil and other extractives have already seen their economies suffer as foreign reserves fall. Furthermore, the World Bank estimates that remittances could decline by as much as 20 percent in the coming year, eliminating a key source of income for many poor families already living hand to mouth.

Low-income countries lack the healthcare infrastructure to respond to the virus or for widespread testing and contact tracing. At the same time, just 20 percent of the poorest people in low-income countries have access to social safety nets of any kind (let alone food-based safety nets), and governments often lack the resources to scale up these protections when they do exist. The sorts of stimulus and relief packages passed by the U.S. Congress since March are a luxury precious few countries can afford.

All of this matters because when incomes decline, so do food security outcomes. Millions of people around the world live hand to mouth, with any disruption in earnings directly impacting their ability to feed themselves or their families. Research has shown that, in the face of economic stress, people commonly substitute highly nutritious foods for cheaper processed foods. Even prior to the pandemic, over 1.5 billion people around the planet could not afford healthy and diverse diets.

The story of food insecurity and Covid-19 does not end, in other words, with unemployment and insufficient social protections. It is also true that malnourished people are more likely to contact the virus in the first place and—perhaps more ominously—there are lingering questions about whether severely malnourished people will be able to mount an adequate and sustained immune response to the vaccine once it is available.

Hunger and Infectious Disease

That malnourishment places people at higher risk of infection is widely known.

Malnutrition has been described as the most common immunodeficiency in the world, and it has already been recognized by researchers as a key underlying vulnerability affecting morbidity and mortality in elderly patients infected with Covid-19. Severe, improper nutrition causes a breakdown in the mucosal barrier (mucus in our mouth and nose that protects against germs), the body’s first line of defense against pathogens. In acute cases, hungry children experience edema or “flaky paint” dermatosis, further eroding their bodies’ protective barriers.

Malnutrition is the leading cause of death among children under five years of age, responsible for 45 percent of such deaths globally, some 3 million each year. Nutrition in the first 1,000 days from pregnancy to a child’s second birthday can have lifetime impacts on health and prosperity. Lacking proper nutrition in this period, physical growth—height, weight, and brain development—can be permanently damaged, leading to a diminished capacity to learn and a greater susceptibility to infection. The first 1,000 days shapes a child’s destiny.

Malnourished children are more than nine times more likely to die from infectious diseases than healthy children are, including from pneumonia, diarrhea, sepsis, meningitis, measles, and tuberculosis. Paradoxically, Covid-19 has caused a dramatic decline in the number of children receiving life-saving routine vaccinations. According to the World Health Organization (WHO) and UNICEF, at least 30 measles vaccination plans have been postponed or cancelled due to Covid-19. Researchers at Johns Hopkins have shown that an additional 6,000 children could die each day from otherwise preventable disease because of the pandemic.

In a vicious cycle, infection makes people vulnerable to malnourishment, and malnourishment leaves people vulnerable to further infection. Infections commonly affect the gut microbiota and produce system-wide inflammation (but especially in the intestines, known as enteropathy), limiting the absorption of nutrients. Diarrhea kills more than 2,000 children each day, for example, depleting the body of necessary fluids and stealing away a child’s ability to extract nutrients from the foods they eat.

Since antiretrovirals became widespread in the treatment of HIV/AIDS, the link between therapeutic effectiveness and malnourishment have also become more apparent. HIV patients burn at least 10 percent more calorie energy than healthy individuals fighting off the virus, and they have lower rates of nutrient absorption. Combining antiretrovirals with proper nutritional supplements has become best practice—and critically important for efficacy—in administering these therapeutics.

The link between therapeutics or vaccines and nutrition applies to almost all infection types, owing to the immune responses’ dependence on proper nutrition. “Vaccinations and nutrition interventions complement each other, and each amplifies the impact of the other. They should, where appropriate, be delivered together, as a core part of a comprehensive primary health care approach, on the road towards universal health coverage,” states one nutrition advocacy coalition. 

Malnourishment and Vaccine Efficacy

There is also a growing body of literature around vaccine efficacy and the nutritional status of patients. In one systematic review of 75 studies on obesity and Covid-19, researchers suggests that obesity is linked with significant increases in morbidity and mortality in infected patients The authors conclude that “a major concern is that vaccines will be less effective for the individuals with obesity.” This has proven to the case among obese individuals vaccinated against H1N1 and influenza.

Other studies have been conducted with undernourished populations, examining the efficacy of routine vaccinations (measles, hepatitis, pneumonia, meningitis, diphtheria) among these populations. While the literature generally suggests that most malnourished people are still able to develop some protective immune response following vaccination, the timing, quality and duration of responses may be impaired by underlying nutritional status. The effectiveness of vaccines among malnourished populations varies considerably depending on the underlying infection and the vaccination method (e.g., oral versus parenteral).

As GAVI, the global vaccine alliance notes, “Much of the evidence for our understanding of immunity in malnourished children is not as strong as it could be and uses outdated laboratory techniques or definitions of malnourishment.” They suggest that studies with mice may provide further insight. In one such study, malnourished mice are shown to have “shorter lived immune memory” after being infected with influenza and developing antibodies.

There is also the question of suitability for administering a vaccine to all ages and populations. The term used in medicine to describe a specific scenario in which a drug or vaccine could cause undue harm to those taking it is a “contraindication.” Contraindications are more common in immunocompromised individuals, pregnant and nursing mothers, and others suffering from moderate or severe acute illnesses—all common among malnourished populations.

The Mission of the Century

Stopping the spread of the virus and saving lives depends on the Covid-19 vaccine working on the largest number of people as quickly as possible.

The vaccine trials to date have tested for the prevention of symptom development, not for complete immunity (so-called sterilizing immunity). This likely means that Covid-19 vaccine will have to reach great numbers of individuals to achieve herd immunity and protect non-vaccinated populations. Some Covid-19 vaccines will likely require multiple doses, lengthening the time required to reduce the spread of the virus.

Maximizing vaccine efficacy among eligible populations will be important in preventing disease transmission. Many questions have yet to be answered about a potential Covid-19 vaccination and more research is required around vaccine efficacy among malnourished populations. From what we know today, however, we must at least acknowledge the possibility that more people will die if we don’t work quickly to address the world’s worst hunger emergencies.

The “mission of the century” may not be arranging airlift capacity for vaccine distribution, as some have suggested; instead, it may be reaching hundreds of millions of people with life saving food assistance beforehand, so their bodies are prepared to defend themselves from this virus and others. We may, in other words, require a new mantra: “Nobody is safe until everybody is fed.”

Chase Sova is a non-resident senior associate with the Global Food Security Project at the Center for Strategic and International Studies (CSIS) in Washington, D.C. He is also senior director of Public Policy and Thought Leadership at World Food Program USA (WFP USA).

Commentary is produced by the Center for Strategic and International Studies (CSIS), a private, tax-exempt institution focusing on international public policy issues. Its research is nonpartisan and nonproprietary. CSIS does not take specific policy positions. Accordingly, all views, positions, and conclusions expressed in this publication should be understood to be solely those of the author(s).

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Chase Sova
Senior Associate (Non-resident), Global Food and Water Security Program