In discussing vaccines and immunization, another term needs to be brought up: “herd immunity.”
Herd immunity refers to resistance against the spread of a contagious disease within a population. This happens when a “sufficiently high proportion” of individuals are immune to a disease, usually because they have been immunized. Herd immunity makes it very difficult “for the germ responsible for the infection being transmitted between people” because enough people have been immunized. “In this way,” writes Dr. Manish Sadarangani of the Oxford Vaccine Group, even people who cannot be vaccinated can be protected.
Harmful bacteria can live “harmlessly” in the bodies of many people, but if these bacteria spread to someone “who is particularly susceptible (such as a young baby) they can cause severe disease.” Dr. Sadarangani observes that by being vaccinated, “individuals are not only protected from being infected themselves but they then also cannot pass this infection onto other people, where it may cause severe disease.”
This is why, on the tail-end of World Immunization Week (it comes to a close tomorrow), Unicef, the UN special agency for children, asserts that “Filipinos have a shared responsibility to ensure all children are immunized.”
Health workers, national and local government officials, civil society, mothers, fathers and community members—each one and everyone—have a role to play “to ensure that Filipinos receive the right information on immunization, families are supported in overcoming barriers, and that children complete their vaccines.”
Through the decades, the world has made remarkable strides to slow down, if not eliminate entirely, the spread of major diseases, including the dreaded smallpox. In the Philippines, polio has been eradicated since 2000, while maternal and neonatal (newborn) tetanus (the result of using infected instruments to cut the umbilical cord during delivery) was eliminated in 2017. But distressingly, the country has fallen behind in routine immunization that protects children from diseases such as measles, diphtheria and hepatitis B. Says Unicef: “It’s time for urgent action.”
In the Philippines, says Unicef, the proportion of children aged 12-23 months who received all basic vaccinations dropped from 77 percent in 2013 to 70 percent in 2017, while the percentage of children with vaccination rose from 4 percent in 2013 to 9 percent in 2017. A total of 80 percent of children received the first dose of measles vaccination, while only 47 percent received the second dose. As a result, “an outbreak this year resulted in more than 700 children contracting measles, a disease that can potentially be lethal to a small child.”
Of course, a lot of the “fear and trembling” among parents has been caused by the sensational news surrounding Dengvaxia, an antidengue vaccine, spurred in large part by the histrionics of the chief of the Public Attorney’s Office. Health authorities worked passionately through the decades to encourage immunization, but vaccine coverage is now threatened by politicians grandstanding on the issue.
But politicians might change their minds if they’re made aware that vaccines make strong economic sense. Vaccines, says Unicef, “prevent illness, freeing up precious resources to invest in strong health systems. Vaccination can also promote a stronger workforce and prevent losses in productivity.”
Parents and other adults might also want to use support for vaccination and other health programs as one of the criteria for choosing candidates in elections. As I said at the start of this column, every child who is immunized serves to guarantee herd immunity to other children who may not be protected against infectious diseases.
Anyone who stands in the way of immunization—be it out of fear, neglect, carelessness, hysteria, or opportunism—should be made to account for putting children at risk, and to answer for every death or illness resulting from a commonly preventable disease.
Immunization is the responsibility of everyone because it protects everyone.