In 2018, approximately 54,000 Ukrainian citizens contracted measles. Meredith Wadman writes for Science, explaining that these infections represent nearly two-thirds of the measles cases in Europe. Nataliya Vynnyk, a Ukrainian pediatrician, says, “The current epidemic is the most massive in the entire post-vaccine period”.

Measles is a viral disease that causes fever, cough and a red rash, in addition to other symptoms. The Mayo Clinic explains that measles is communicable even before the distinctive red rash appears, making the disease easily transmissible by those who don’t know they are infected.

The World Health Organization (WHO) states that two doses of the measles vaccine prevents 99 percent of infections.

In 2014, civil war broke out in Ukraine. The resulting chaos delayed ordering the vaccine, resulting in shortages during 2015. As a result, only 42 percent of infants were vaccinated in 2016. That same year, less than a third of six-year-olds received the follow-up dose needed for full protection.

Because so many children are currently unvaccinated, the disease can spread rapidly. According to the WHO, 95 percent of children need to be vaccinated to prevent transmission between communities and eradicate the disease.

Ukraine has established incentives for physicians to vaccinate their patients and is encouraging parents and grandparents to get their children vaccinated. These programs have led to major gains in the number of vaccinated children following the recommended vaccine schedule. More than 90 percent of infants and six-year-olds got the vaccine on time in 2017.

However, there are still children who have missed vital doses of vaccine, and the Ukrainian government is currently running “catch-up campaigns” to ensure the health of this susceptible population.

Anti-vaccine sentiment has also played a role in the outbreak. The WHO partially credits lower vaccination rates to a lack of confidence in vaccines. This prevents physicians from encouraging patients to get vaccinated. Parents are also less likely to advocate for vaccines for their children.

The website, “The Vaccine Reaction,” evaluated vaccination rates and the number of measles outbreaks from 2016-2018. The site explains that many cases of measles were diagnosed by a physician instead of a lab. They argue that because the number of lab-confirmed cases did not rise in proportion to the number of doctor-diagnosed cases, the outbreak is not as severe as health officials report.

While there will be errors in any estimation, this discrepancy does not indicate that the outbreak was insignificant. With more people infected, it is harder for labs to analyze all the new samples being sent, meaning that fewer cases could be lab-confirmed.

“The Vaccine Reaction” also notices a correlation between the number of vaccines being given and the number of people infected. Essentially, the authors argue that the “catch-up campaigns” are responsible for the outbreak. At surface level, this claim may appear reasonable, but it takes time for outbreaks to develop and for infection to spread.

In the 2016-2018 time frame, the fewest children were vaccinated in 2016, and infection rates were the lowest of the three years. In 2017 vaccine rates and the number of measles cases increased.

What “The Vaccine Reaction” failed to account for is that it takes time for the disease to become prevalent enough for an uninfected person to be exposed and infected. As a result, peaks in disease prevalence weren’t noted until 2018, when the disease had time to pass among unvaccinated populations. Radio Free Europe reports that in 2015, while most of the Ukrainian population was adequately vaccinated, there were only 105 cases of measles in the country. In 2017, more than 2,000 cases were reported.

Hopefully, evidence from around the world can serve as a reminder to the global community that vaccines are effective and that the public must embrace their efficacy.