Vaccine hesitancy and the deadly spread of measles


With 3,65,000 cases of measles reported globally in the first six months of this year, vaccine hesitancy appears to have grown more dangerous to public health. In 121 Indian districts that have higher rates of unimmunised children, 24% did not get vaccinated due to apprehension about adverse effects.

With 30% increase in measles cases across the globe in 2018, the World Health Organization, in January 2019, included ‘vaccine hesitancy’ as one of the ten threats to global health this year. Eight months later, the threat from vaccine hesitancy, which is defined as the “reluctance or refusal to vaccinate despite the availability of vaccines”, only appears to have grown more dangerous to public health.

After a surge in the number of measles cases globally in 2018, there have been 3,65,000 measles cases reported from 182 countries in the first six months of 2019. The biggest increase of 900% in the first six months this year compared with the same period last year has been from the WHO African region.

The Democratic Republic of the Congo (DRC) with 1,40,000 suspected cases, Madagascar with 1,27,000 cases and Nigeria with 38,000 cases account for most cases this year from Africa. There has been a sharp increase in the WHO European region too with 90,000 cases recorded in the first six months, which is more the numbers recorded for the whole of 2018.

The spread of measles infection in the European region has been unprecedented in recent years — 1,74,000 cases have been reported from 49 of the 53 countries between January 2018 and June 2019. Last month, four European countries — the U.K., Greece, the Czech Republic and Albania — lost their measles elimination status.

A 2018 report on vaccine confidence among the European Union member states shows why the vaccine coverage has not been increasing in the European region to reach over 90% to offer protection even to those not vaccinated. It found younger people (18-34 years) and those with less education are less likely to agree that the measles, mumps, and rubella (MMR) vaccine is safe.

According to a March 2019 report, only 52% respondents from 28 EU member states agree that are definitely effective in preventing diseases, while 33% felt they were probably effective. More alarming is that 48% believe that vaccines cause serious side effects and 38% think vaccine actually cause the disease that they are supposed to protect against. A striking similarly was seen in India too.

A December 2018 study found that low awareness was the main reason why 45% of children missed different vaccinations in 121 Indian districts that have higher rates of unimmunised children. And 24% did not get vaccinated due to apprehension about adverse effects. This clearly shows much work remains to be done to educate the beneficiaries and address misinformation.

With social media playing a crucial role in disseminating vaccine disinformation, the commitment by Facebook to “reduce distribution” of vaccine misinformation will be highly helpful in winning the war against vaccine deniers.

Measles vaccine not only provides lifelong protection against the virus, it also reduces mortality from other childhood infections. This is because measles viruses kill white blood cells thus erasing the naturally acquired immunity thus leaving the child vulnerable to other infectious diseases for as long as two-three years.

Published in The Hindu on September 18, 2019