Immunisation: Crisis and Benefits

The discovery of the benefits of vaccines has arguably been among the greatest developments in modern healthcare. Based on objective data, UNICEF states that,

Immunization is one of the most cost-effective public health interventions to date, averting an estimated 2 to 3 million deaths every year. As a direct result of immunization, the world is closer than ever to eradicating polio, with only three remaining polio endemic countries – Afghanistan, Nigeria and Pakistan. Children under 5 deaths from measles, a major child killer, declined by 85 per cent worldwide and by 89 per cent in sub-Saharan Africa between 2000 and 2016. And as of March 2018, all but 14 countries have eliminated maternal and neonatal tetanus, a disease with a fatality rate of 70 to 100 per cent among newborns.

However, recent articles on the WHO, UNICEF, BBC and CNN websites have highlighted emerging challenges that are counteracting the attempts at achieving universal coverage. The WHO quotes Dr Seth Berkley, who summarises the factors as the following:

Complacency about the disease and the spread of falsehoods about the vaccine in Europe, a collapsing health system in Venezuela and pockets of fragility and low immunization coverage in Africa are combining to bring about a global resurgence of measles after years of progress.

That the spread of falsehoods about vaccines is not limited to Europe is evident from the CNN article, which highlights problems in the USA and steps being taken by some local authorities to try to mitigate against the risks posed by unvaccinated individuals who may be carriers.

UNICEF provides some useful data on vaccine coverage, some of which is shared below. The first series of pictures are based on global coverage of the first dose of diphtheria, polio and tetanus.

The review of the third dose of DTP is presented in an interesting way, highlighting the countries with the greatest deficits in care. Of the 19.9 million infants who are not fully vaccinated with DTP3, almost 8 million (40%) live in fragile or humanitarian settings, including countries affected by conflict. About 5.6 million of them live in just three countries – Afghanistan, Nigeria and Pakistan – where access to routine immunization services is critical to achieving and sustaining polio eradication.

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When it comes to a review of measles vaccination, we see that rates remain too low to prevent outbreaks. Globally, 85% of children have been vaccinated with the first dose of measles vaccine by their first birthday through routine health services and 67% with a second dose. 167 countries have included a second dose of measles vaccine as part of their routine vaccination schedule. Nevertheless, coverage levels remain well short of the WHO recommended measles immunization coverage of at least 95% to prevent outbreaks, avert preventable deaths. and achieve regional elimination goals.

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The final image relates to the coverage of HPV vaccination. Human papillomavirus (HPV) is the most common viral infection of the reproductive tract, and can cause cervical cancer, other types of cancer, and genital warts in both men and women. The benefits of HPV vaccination are discussed in greater detail here. By 2017, the HPV vaccine had been introduced in 80 countries covering 22  percent of global cohort of 15 year old girls.

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To summarise, it is important that we maintain vigilance and continue to both promote and practice effective vaccination so that we can reduce and eventually eliminate the burden of unnecessary deaths that affects vulnerable people across the globe.