Some target the leading killers of children and their widespread use can prevent hundreds of thousands of deaths every year. Without them, child deaths would not have fallen from 12 million in 1990 to 5 million in 2019, according to the Global Burden of Disease (GBD), and without sustained increases in their coverage, many countries will not achieve the Sustainable Development Goals by 2030.
Measles is our best example, which is why recent backsliding on vaccine coverage and the resulting outbreaks ring such loud alarm bells. In 1990, an estimated 700,000 children under five died of measles, according to the GBD. By 2019, that number had dropped to just 70,000 – a 90% reduction! Over the same period, global measles vaccine coverage (one dose) rose to 84%, according to the World Health Organization (WHO).
Similarly, tetanus killed an estimated 215,000 children in 1990. By 2019, that number had dropped to 18,000, another 90% reduction. Over the same period global tetanus vaccine coverage (3 doses) also hit 83%. Millions of children are alive today because of sustained, high coverage of these two vaccines in most countries.
Assuming governments maintain the relatively high rates of measles and tetanus vaccine coverage, the next wave of child mortality reductions will be underwritten by vaccines that target pneumonia and diarrhea – the two leading infectious causes of child death. Together, they account for a massive 1.2 million child deaths (672,000 from pneumonia and 501,000 from diarrhea), 23% of all child deaths, according to the GBD.
The pneumonia-fighting vaccines include the already available and in wide-use Haemophilus influenzae type b (Hib) vaccine, the already-available and not yet in wide-use pneumococcal conjugate vaccine (PCV), and the not-yet available but very promising respiratory syncytial virus (RSV) vaccine. Together, these three vaccines target the leading bacterial and viral causes of child pneumonia and when more than 90% of children receive them, expect to see child pneumonia mortality decline by more than half. Wider uptake of influenza and COVID-19 vaccines will also reduce child deaths from respiratory infections.
Countries shouldn’t have to wait too long to see the impact of these vaccines after they are introduced. It took just seven years following the introduction of PCV in the USA for rates of pneumococcal infection among children to fall from 80 per 100,000 to less than 1, according to the Centers for Disease Control and Prevention (CDC). After just four years of the PCV in Kilifi, Kenya, hospital admissions of children with clinically-defined pneumonia fell by 27%,and the incidence of pneumonia fell from 1,220 per 100,000 children each year to 891 per 100,000 children, according to a Lancet Global Health study.
Complement the pneumonia-fighting vaccines with the wide adoption of the rotavirus vaccine (RotaC), which targets the leading cause of severe diarrhea in children, and countries could be more than half way to ending preventable child deaths and achieving Sustainable Development Goal 3.2. This target requires all countries to drive child deaths to at least 25 per 1,000 live births and neonatal deaths to less than 12 per 1,000 live births by 2030.
Higher coverage of the measles, tetanus, Hib, pneumococcal, and rotavirus vaccines is clearly associated with lower child mortality. High coverage of these five vaccines cross the 25 countries who are losing more than 40,000 children under five each year is associated with lower child mortality rates. As a result, the countries with higher coverage (above 70%) of the child-survival vaccines, including Cote d’Ivoire, Niger, Cameroon, Burkina Faso, Ethiopia, Mozambique, Tanzania, Kenya, Sudan, Bangladesh, and Madagascar, are better-positioned to achieve SDG 3.2. Pushing coverage of these vaccines to above 90% may well be their best bet in getting there.
Other countries with low vaccine coverage are significantly off-track, including Somalia, Chad, Mali, Nigeria, and South Sudan. For them, driving coverage of the measles, tetanus, Hib, PCV, and RotaC vaccines to above 70% is likely their most urgent child survival priority and smartest investment. For another group of countries like India, Pakistan, Angola, Afghanistan, Mali, and the Democratic Republic of Congo, filling obvious gaps in coverage, especially of the PCV and RotaC vaccines, could prevent the most child deaths. Further, as new child survival vaccines (e.g., RSV) become available, these countries should introduce them.
It is interesting that China, Indonesia, and the Philippines have achieved relatively low rates of child mortality without high coverage of the child-survival vaccines. For them, introduction and high coverage of the child survival vaccines has the potential to drive their child mortality rates down even further to high-income country levels – below 10 deaths per 1,000 live births – removing a major burden from families and the healthcare system.
It is important to note that although wide adoption of the child survival vaccines is a necessary precondition for dramatic reductions in child deaths in most low- and middle-income countries, it will not be sufficient to end them. This is because the child survival vaccines do not protect against all of all of the leading causes of pneumonia and diarrhea, and because the other major causes of child death – preterm birth, birth trauma, newborn sepsis, congenital defects, and malaria – are not vaccine-preventable.
To close remaining child survival gaps, countries will also need to invest in non-vaccine solutions where the evidence shows a direct link to mortality declines, especially female literacy, contraception, nutrition, clean air, and access to healthcare that provides safe birth, quality newborn care, and diagnosis and treatment of the major childhood diseases at no cost for the most vulnerable children and their mothers.
Mali has just taken a big step forward in this direction with the announcement that primary health care will be provided to all children under five and pregnant women at no charge. The countries that do the same, and make sure that all of the child-survival vaccines are part of the package, are best positioned to reap the rewards of the child survival revolution.
Updated September 2021