By Katherine Lewis
Editor’s Note: This article is the first of a 3-part series on measles and vaccines.
Measles, a potentially lethal respiratory illness, was declared eliminated in the United States in 2000 due to the widespread success of the measles vaccine program. This most common vaccine for measles is the MMR vaccine, which protects against measles, mumps, and rubella. Children ages 12 months to 12 years may also receive the MMRV vaccine, which protects against these three diseases along with varicella, commonly known as chickenpox. While one dose of the MMR vaccine is 93% effective in preventing measles, two doses increase the effectiveness to 97%. Therefore, The Centers for Disease Control and Prevention (CDC) recommends that all children receive two doses of the measles vaccine, the first administered at 12-15 months, the second at 4-6 years. Despite the effectiveness of the MMR vaccine in the United States, measles remains common in other countries and has recently been the subject of renewed attention in the US in the face of anti-vaccination debates.
Madagascar, an island nation off the coast of Africa, is currently suffering its worst measles outbreak in decades. Cases have been reported in every region of the country as well as in all major towns and cities. This outbreak is largely caused by the highly contagious nature of measles and very low rates of vaccination across the country. The global strategy for eliminating measles rests on the effectiveness of the vaccine as well as the concept of herd immunity, in which high rates of vaccination prevent the spread of the disease. This strategy is effective because the disease eventually dies out if a large majority of the population is immune.
While herd immunity does not guarantee individual protection, it is a crucial strategy for the prevention and eradication of diseases which are highly contagious, but easily prevented with a vaccine, such as measles. In order for herd immunity to be effective, around 95% of the population must be vaccinated. The CDC estimates that 91.5% of the US population had received at least one round of the MMR vaccine in 2017. In contrast, it is estimated that only 50% of Madagascar’s population was vaccinated at the onset of the current outbreak due to “a weak, underfunded health system, and a failure of routine immunization delivery.”
Despite the wide discrepancy between vaccine coverage in the US and Madagascar, health workers such as Madagascar Peace Corp volunteer Dr. Lon Kightlinger, “point to Madagascar as a dangerous portent” for the US. Kightlinger, former State Epidemiologist of South Dakota, was interviewed by CNN Health and stated that the outbreak in Madagascar “should be a wake-up call…not only for every person, [and] for every health center in Madagascar, but for the whole world. These diseases come back and clobber us if we are not protected…These are living viruses who are very clever, and they will find us.”
As discussed by Kightlinger, under-vaccination in Madagascar is largely due to a lack of resources and access to live-saving vaccines. In contrast, Kightlinger attributes under-coverage in the US to the fact that, “we Americans…have concocted all of these excuses and reasons to be complacent about measles.” This attitude, in turn, contributes to voluntary rejections of vaccination, even when the resources are readily available. Meanwhile, many in Madagascar will travel long distances to vaccine drives in order to vaccinate themselves and their children, anti-vaccination campaigns in the US pose a new challenge of volitional rejection of existing vaccine access.
This lack of understanding about vaccines in countries such as the US, where the population is privileged with such access to healthcare, “infuriates physicians” in countries like Madagascar, where access to vaccines represents the difference between life and death.
Next in the series, we will take a closer look at measles in the US, including recent outbreaks around the country.