Measles is an exceptionally pernicious disease. It is nothing to be trifled with.
Nonetheless, at least a million children in the Philippines are not fully vaccinated against this malaise, according to the Field Health Services Information System, which is a health reporting network created by the Department of Health.
However, it should be added that this figure varies significantly from year to year depending on the success of public information campaigns.
The current low vaccination rate has been ascribed to an unwillingness of parents to have their children vaccinated – a phenomenon called “vaccine hesitancy”.
However, the vaccine for measles is relatively safe, and experts say the disease is extraordinarily contagious.
For example, the “basic reproduction number”, or R0, of measles is 12 to 18. This implies that anyone with measles is likely to infect 12 to 18 other people.
R0 is pronounced “R naught”.
By comparison, the R0 of influenza is 1.3, and for early versions of Covid-19, the R0 was 2 or 3.
One reason for this extraordinary contagiousness is that the virus is airborne, and it remains infectious for up to two hours while floating around in the air in an enclosed space.
In other words, if a contagious preschooler coughs or sneezes in a classroom, anyone entering that classroom within the next two hours could be exposed to the virus.
What’s more, after initial exposure and during the incubation period, which lasts 10 to 14 days, there are no signs of the disease aside from some cold-like symptoms.
That is to say, a person with measles can be infectious several days before the appearance of the characteristic rash.
Specifically, infected people are contagious for about eight days, starting four days before the characteristic rash appears and lasting approximately for another four days after the rash.
The disease is so infectious, epidemiologists say, that a population must be 95 percent vaccinated to control the spread of the disease.
Consequently, the Department of Health is aiming for a 95 percent coverage rate for children, but as of Jan. 20, 2025, data suggests that only 61 percent of the target population has been reached.
As for the timeline of the disease, after initial exposure to the virus, there is an incubation period of 7 to 14 days.
The initial symptoms are a very high fever, up to 104 degrees Fahrenheit, or 40 degrees Celsius. This is followed by a severe cough; runny nose; red, watery eyes; and tiredness.
Then, after two or three days of fever and coughing, Koplik spots develop.
Named after Dr. Henry Koplik, the New York physician who first described them in 1896, Koplik spots are small, bluish-gray spots on the inner lining of the cheeks and the backs of the lips. They look like grains of white sand or sugar on a reddish background.
Koplik spots are a unique indicator of the presence of measles, the disease’s “pathognomonic symptom”.
In medicine, a pathognomonic symptom is a clear indicator of the presence of a specific disease.
The Koplik spots last for three to five days. Then a red, blotchy rash starts on the face at the hairline and spreads downwards to the neck, torso and arms and legs. The rash usually lasts 5 to 6 days.
The entire course of the illness, from the onset of symptoms until the rash disappears, is 2 to 3 weeks.
One of the worst outcomes of measles is that it cancels most of the immunities that have been established since birth.
Scientists call this “immune amnesia” – the measles virus disrupts pre-existing memory cells responsible for immunity to previously encountered diseases such as some types of pneumonia, which can be deadly.
Other long-term effects of measles include brain damage, specifically encephalitis, or swollen brain; hearing loss; increased risk from other infectious diseases; and, if the victim is a woman of childbearing age, risk of complications during pregnancy.
As for mortality, measles is deadlier than Covid-19 and influenza. The Case Fatality Rate for Covid-19 is about 3 percent, while the CFR for influenza is 0.1 percent. The CFR for measles is up to 5 percent in developed countries and up to 10 percent in lesser developed nations.
Most fatalities are young children.
In terms of the number of children who have missed out on routine measles vaccines, the Philippines is the second highest in East Asia and the Pacific Region and the fifth highest globally.
A 2019 measles outbreak was attributed to lower vaccination rates, allegedly caused by the Dengvaxia vaccine controversy of 2017, in which a dengue vaccine was found to increase the risk of disease severity for some people.
Also contributing to vaccine hesitancy recently was the suspension of immunization programs during the Covid-19 pandemic.
Meanwhile, the country has experienced significant surges in measles cases in recent years.
The largest measles outbreak in the World Health Organization Western Pacific region occurred in the Philippines, with reported cases increasing from 2,428 in 2017 to 20,827 in 2018 and 48,525 toward the end of 2019.
A 2023 report by the Department of Health indicated a nearly 300 percent increase in cases compared to the previous year.
. According to the Department of Health, vaccinations for measles in the Philippines are free and easy to get in health centers and from barangay health workers.
The most common vaccine is called MMR – meaning “measles, mumps and rubella” – because it contains antigens for all three diseases.
The first dose for children should be given at age 12 to 15 months. This should be followed by a second dose at age 4 to 6 years.
Due to the ubiquity of measles before the formation of national vaccination programs in the 1960s, people born prior to 1957 do not need to be vaccinated – the assumption being that they were exposed to the disease in their youth and already are immune.
Today, measles vaccines are included in national vaccination programs in every country.
The MMR vaccine is considered safe, but, as with other vaccinations, there are a few temporary but mild side effects – soreness, light fever, mild rash, swollen glands, and joint pain.
Due to its structure, the measles virus is very stable and not subject to continual mutations, like Covid-19 or the influenza virus. As a consequence, vaccination against the disease should last for a lifetime.
Bryce McIntyre, PhD, resides in San Andres. He holds a doctoral degree from Stanford University, Palo Alto, California, USA