Health Viewpoints

The global threat of measles outbreaks looms large. Despite significant progress in measles control, outbreaks continue to surge across various regions, jeopardizing public health worldwide.

In Europe, where many countries have lost their measles elimination status in recent years, over 900 cases were reported by the end of February alone, surpassing the total for 2022. In the United States, where the virus was declared eliminated in 2000, dozens, sometimes hundreds, of cases are reported annually, with noticeable spikes occurring every few years.

Lower vaccination rates, often singled out as the main reason behind local outbreaks, don’t tell the whole story.

So what exactly is behind this upsurge? What factors contribute to measles recurrence, and what strategies can be implemented to address the situation?

Measles: A Complex Challenge in the Face of Global Resurgence

Measles, also called rubeola, primarily spreads as an airborne particle, posing a significant risk of transmission. However, its ability to survive on surfaces for over two hours makes it even more concerning, extending its infectivity window. A person with measles can potentially transmit the virus to 90 percent of the people with whom they come in contact.

Before 1963, large-scale measles outbreaks occurred regularly, infecting millions of people at a time. Implementation of preventative health measures such as vaccination and an improved health care system were believed to have led to the elimination of the virus in the United States and many other countries two decades ago.

However, even in 2000, global measles deaths were estimated to be around 733,000. In 2021, an estimated 9 million measles cases and 128,000 deaths occurred worldwide, with 22 countries grappling with significant outbreaks that continue today.

The resurgence of measles has been a mounting concern for decades, with 10 countries that previously achieved measles elimination experiencing disruptive outbreaks in 2016. Since the beginning of 2023, measles has been reported in 17 countries across the World Health Organization’s (WHO) European Region. Globally, in the first two months of 2022, reported measles cases saw a staggering 79 percent increase compared to the same period in 2021.

While most outbreaks primarily affect parts of Africa and Asia due to poor sanitation conditions in underdeveloped regions, some suggest a potential link to the ongoing COVID-19 pandemic due to delayed vaccinations. However, measles is difficult to contain due to the role travel and migration play in spreading it.

Measles poses a significant challenge due to the absence of an antiviral treatment that targets the virus. As a result, medical interventions primarily focus on symptom management and alleviating complications. One common symptom of measles is a high fever, usually addressed with over-the-counter medications like ibuprofen or acetaminophen.

The challenge lies in sustaining measles elimination, as no region has successfully maintained long-term eradication.

Phases and Potential Complications

Measles infection progresses through three distinct phases:

1. Incubation phase: This initial phase lasts approximately 10 to 14 days, with no symptoms present. The virus silently replicates within the body.


2. Prodromal phase: Following the incubation period, the prodromal phase emerges, lasting two to four days. Symptoms such as high fever, cough, runny nose, and small white spots (Koplik spots) on the inside of the cheeks become evident.


3. Rash phase: The rash phase is a hallmark of measles, typically lasting 2-4 days. It begins on the face and subsequently spreads downward over the body.

Measles can be quite taxing on the infected person. In the United States, approximately 1 in 4 measles patients require hospitalization, and the infection claims the lives of about one to three individuals per 1,000 cases. Moreover, measles can lead to severe complications.

The most serious complications include blindness, brain swelling (encephalitis), severe diarrhea, and heightened vulnerability to other infections. Children under the age of 5, adults over 30, and malnourished individuals face a greater risk of experiencing severe complications from measles.

The Impact of the Pandemic on Vaccination Efforts

In late 2021, the WHO issued a notice warning of the pandemic’s threat to the progress made against measles worldwide. The global initiative was meant to reduce measles to a minimum worldwide, but in 2022, approximately 40 million vulnerable children remained susceptible to measles because they missed a vaccine dose.

During the pandemic, measles vaccination campaigns faced significant delays due to disruptions in supply chains and other factors. About 61 million vaccine doses globally were missed or postponed in 2021. Presently, almost 40 countries, mainly in Asia and Africa, are declared at risk of measles outbreaks.

The impact of the COVID-19 pandemic extended beyond measles, affecting vaccination efforts for various contagious diseases such as yellow fever, polio, and tuberculosis. However, despite a rigorous vaccination campaign in some countries, infectious diseases such as measles have nevertheless been on the rise for quite some time. How do we explain this?

Vaccination Campaigns Can’t Eliminate Measles

Measles vaccines are primarily categorized into two types:

1. Measles-Mumps-Rubella (MMR) vaccine: The MMR vaccine is a combination vaccine that protects against measles, mumps, and rubella. Administered in two doses, typically at 12 to 15 months and 4 to 6 years of age, it contains weakened live viruses for each disease, providing long-lasting immunity against measles.


2. Measles-Mumps-Rubella-Varicella (MMRV) vaccine: Another combination vaccine, this protects against measles, mumps, rubella, and varicella (chickenpox). Like MMR, it contains weakened live viruses and is commonly used as an alternative to separate MMR and varicella vaccines for children aged 12 months to 12 years. It is typically administered in two doses.

Breakthrough cases, where vaccinated individuals contract the virus, can occur in areas with low vaccination rates (less than 10 percent of cases) and even in areas with high rates (more than 10 percent of cases). Such cases can result from primary vaccination failure (complete rejection of the vaccine by the body) or secondary vaccination failure (waning immunity).

Breakthrough Infections: Measles Outbreaks After Vaccination

Studies on measles outbreaks have provided mixed results, with evidence demonstrating both the vaccine’s effectiveness in preventing spread and instances of virus acquisition among vaccinated individuals.

Several intrinsic issues can lead to breakthrough infections after vaccination:

• Vaccine failure: While the measles vaccine is highly effective, it is not 100 percent foolproof. In a small percentage of individuals, the vaccine may not provide complete immunity or may wane over time. This can leave the person susceptible to infection if they come into contact with the measles virus.


• Improper timing or dosage: The effectiveness of the measles vaccine depends on factors like timing. Following the recommended two-dose schedule is vital for optimal protection. Incomplete vaccination or delays between doses increase the risk of breakthrough infections.


• Strain mismatches: The measles virus can vary in strains across regions and time, potentially leading to breakthrough infections if a vaccinated individual encounters a different strain than the one targeted by the vaccine. However, the vaccine offers a certain degree of cross-protection against various strains.


• Immune system factors: Underlying health conditions or certain medications that weaken the immune system can increase susceptibility to breakthrough infections. Age also influences immune response, with infants and young children exhibiting a less robust response to the vaccine.

Addressing Immune System Factors for Measles Prevention

The impact of immune system factors on public health requires serious consideration amid the rising measles cases in the past 10 years. We need to look at the population’s overall health conditions. People tend to blame the surging of viral pathogens on poor sanitation conditions, failure of vaccination campaigns or infection controls, and international travel.

However, we must consider whether we are getting healthier with our current lifestyles. Are we consuming nutritious diets? Do we get sufficient rest and sleep? Are we doing anything that may harm our immune system knowingly or unknowingly?

Relying solely on increasing vaccination campaigns may not be optimal for achieving herd immunity. Genuine herd immunity should be established more naturally via improving lifestyle, adopting a better diet, and implementing natural and holistic prevention approaches.