Measles cases will spur US vaccines debate

Analysis

Measles is highly contagious: 90% of people who are exposed to it, and who have not been vaccinated, are likely to catch it. In most cases, the disease has mild symptoms, but it can be fatal. Unvaccinated infants are most at risk. Measles can also cause hearing loss or brain impairments.

For the last 20 years, the vaccination rate in the United States has been about 92% of infants. Those who have not been vaccinated include children who are too ill to receive the vaccine, or those from families who have refused the vaccine on personal or religious grounds.

Before the vaccination for measles, it is estimated there were 3-4 million measles cases annually, with about 400-500 ending in the patient's death.

Reasons for refusal

The main personal reasons for refusing immunisation are fears that the measles-mumps-rubella (MMR) vaccination may cause autism. Anti-vaccination groups have been active in demanding the right to refuse.

While some groups have promoted concerns about autism, the concern is based on a since-discredited report: recent reports argue there is no link between the MMR and autism. Nonetheless, the case is an instructive example of what can make concerned citizens decide against having vaccinations.

The 92% US immunisation level for measles has allowed the United States almost to achieve 'herd immunity', where a level of immunisation that would seem to be sufficient to prevent the spread of the disease has been achieved.

Outbreaks in the United States have tended to be clustered in communities where herd immunity has not been gained:

• In 2014, there were nearly 700 cases among Ohio's Amish community.
• In 2017, 75 cases of measles were reported in Minnesota's Somali community.
• In early 2018, more than 275 cases of measles were reported in the mostly Jewish districts of Brooklyn and north-western New York City -- almost one-third of the national total.

The outbreak of measles in the United States can be traced to initial infections being brought into the country from children who have visited or settled more permanently in countries with high numbers of cases, such as Israel, Ukraine, the Philippines and Somalia.

Diseases can also spread more easily among more homogenous and closely knit groups which live and work near each other. In other cases, a group could have brought with it to the United States a distrust of government that includes health agencies and officials -- this was noted among those from former Soviet-bloc countries. Similarly, there can be concerns about pharmaceutical companies and their motivations.

In New York's current case, the city government is so concerned that Mayor Bill de Blasio has declared a public health emergency. The city government will also issue 1,000-dollar fines if families do not have their children vaccinated.

Political implications

According to the Centers for Disease Control and Prevention, nearly 100 people brought measles to the United States in 2018. There have also been increased outbreaks of hepatitis A, especially in areas where there has been some ideological resistance to vaccinations.

The issue of vaccination pits individual rights (in this case, to refuse vaccinations) against the government's need to assure public health -- which is the undercurrent to current debates about universal healthcare and public health provision (see UNITED STATES: Republicans will avoid health pre-2020 - April 9, 2019 and see UNITED STATES: Ageing may hinder lowering drug prices - March 29, 2019).

Since herd immunity does not require universal immunisation, and since the numbers of 'anti-vaxxers' who are against vaccinations has been reasonably low, the country has been able to allow exemption from vaccination for personal and religious reasons.

However, the country has not quite achieved herd immunity from measles and with the increased importation of measles recently, the United States will need to nudge the proportion of those vaccinated against measles up to 95%, which is thought necessary to secure herd immunity.

At the national level, Trump has urged people to be vaccinated, although earlier comments and tweets during his 2016 presidential campaign have warned about vaccination.

Most Democratic candidates for their party's 2020 presidential nomination have also spoken in support of vaccination. However, many have notably not addressed the issue of whether it should be made mandatory.

State and local levels

At the state and local level in affected areas, though, authorities are taking stronger measures. In Minnesota, a public education programme has seen a rapid increase in vaccinations among the Somali-American community since 2017.

At present, nearly all states allow exemptions for religious beliefs and more than 15 states allow exemptions for personal reasons. In the affected areas of New York, however, the local health commission banned children who had not been vaccinated from going to school.

On the West Coast, where the anti-vaxx movement is particularly strong and there have been outbreaks of measles, state governments are also considering banning unvaccinated children from attending public school and denying parents the right to refuse vaccinations on religious grounds.

Outlook

Such government interventions have prompted anti-vaxx activists to step up their campaigns, particularly in response to fears that insurers would refuse to pay for treatment for unvaccinated children who catch the disease.

Meanwhile, social media firm Facebook has declared that it will not allow unscientific anti-vaccine claims to be promoted on its pages.

With electioneering already under way ahead of 2020, increased outbreaks and media attention, supposed links between immigration and disease, and impending local legislation making vaccination mandatory, the debates over vaccination and public health are bound to intensify.