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Vaccination: Is it safe?

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By Michelle Anne P. Soliman, Reporter

In April 2016, over a million public school students in the National Capital Region (NCR), Central Luzon, and Calabarzon lined up to take part in the immunization program of the first dengue vaccine. It was recommended that the three doses of the vaccine be administered at six-month intervals. It was more than a year into the program, in November 2017, when Sanofi Pasteur issued a warning that immunized people who had not previously been infected with one of the four known varieties of dengue may experience a more severe version of the disease.

The controversy surrounding the immunization program triggered fears of vaccination in general. According to the WIN/Gallup International Vaccine and Confidence Index, vaccine confidence among Filipinos dropped to 32% in 2018 from 93% in 2015.

In recent media reports, Department of Health (DoH) Undersecretary Eric Domingo was quoted as saying that Dengvaxia, the dengue vaccine, will probably not be getting a certificate of product registration (CPR) after the lapse of its one-year suspension. “The one year suspension of the Dengvaxia CPR is not yet lifted and I don’t see it being lifted anytime soon. Dengvaxia will not likely be making a comeback,” he said.




THE IMPORTANCE OF VACCINATION
Smallpox, an acute contagious disease caused by the variola virus, was believed to have originated in India or Egypt over 3,000 years ago. In 1798, English physician and scientist Edward Jenner demonstrated that inoculation with the vaccinia virus which caused cowpox could protect humans from the more virulent smallpox. In 1967, the World Health Organization (WHO) launched a global immunization campaign to eradicate smallpox. The campaign worked. The last naturally occurring case of the disease was in Somalia in 1977.

“Vaccination has been one of the powerful achievements of modern public health apart from using antibiotics that help to control infections. It is really key that we do everything and that vaccination [be] provided to everybody who will need and can benefit from [it],” Dr. Gundo Weiler, World Health Organization (WHO) representative to the Philippines, said at a forum on vaccination on Dec. 3 at the Crowne Plaza in Ortigas.

According to the “10 Facts of Immunization” published on the WHO official website, 2 to 3 million deaths annually are prevented by immunization.

Dr. Weiler noted that vaccine coverage from birth to 12 months is crucial for protection from and prevention of diseases. Annually, the Philippine Pediatric Society (PPS) prepares a childhood immunization guide for the vaccines against diseases ranging from tuberculosis to German measles to be administered at recommended periods.

Vaccines prevent the spread of diseases and minimize the severity of illnesses.

“From a public health point of view, we are also interested to see how epidemics spread in communities. If only a few people are vaccinated in a community, the virus or disease will still continue to spread. But if we get to a critical mass of people being immunized [in the community], then we can break the chain of transmission,” Dr. Weiler said.

In her presentation, Dr. Anna Lisa Ong-Lim, president of the Pediatric Infectious Disease Society of the Philippines (PIDSP) defined vaccines are substances containing inactivated or weakened micro-organisms [which are] “introduced into the body to train the immune system to defend itself quickly.”

When a person is vaccinated, Dr. Lim further explained, one does not just catch the disease but also avoids the complications that come with it.

IS IT EFFECTIVE?
This year, WHO reported that there had been 17,296 measles cases in the Philippines between January to November, a huge increase compared to the 3,706 cases recorded during the same period in 2017.

“Even if people refuse to call it an outbreak, it’s an outbreak,” Dr. Lim said, adding that the Philippines had progressed in the elimination of measles cases in 2014. However, “the loss of vaccine confidence has not helped.”

“Measles are an indicator of the strength of the immunization program. If you have good measles coverage, you know that you were able to bring a child through to their entire vaccination series successfully. Because in the current program, when you talk about a fully immunized child, this is a child who has received all the doses of vaccines up until measles which is the last dose [given] between nine to 12 months [of age],” she explained.

Parents understand the necessity of vaccines since these protect the child from disease. “It’s not some abstract disease that they have never seen [and] that they have difficulty comprehending. But for people to avoid being protected for a disease that they know can kill, you know there’s a problem,” Dr. Lim said.

KNOWING THE RISK-BENEFIT RATIO
Dr. Lim noted that vaccines are effective and safe, however, certain health problems are at times associated with vaccinations. For the benefit of public health, vaccines are administered despite the possibility of adverse reactions, an unintended effect caused by the vaccine.

“If a vaccine is benefiting 99% of the children you are giving it to, will you be using it or not? But we cannot say [that] for every vaccine that it is 100% effective and safe. That is a fact of it,” said Dr. Achyut Shrestha, medical officer at WHO Philippines.

“If you accept those benefits, it comes with a risk. In a public health perspective, you have to take a risk to benefit the larger population,” he said.

Physicians play a role in ensuring safe vaccination by conducting screenings.

“We ask questions with regards to the patient,” said Dr. Salvacion Gatchalian, president of the Philippine Pediatric Society (PPS), adding that this consultation includes asking whether the patient has had previous vaccine reactions, allergies, or currently has a fever.

Continued safety monitoring of a new vaccine is also advised since the number of subjects in clinical trials is limited. “Even after the licensure of the vaccine, there must be continued surveillance to look at adverse reactions that may not have been identified during the clinical trials,” she noted.

Dr. Gatchalian said that safe vaccination entail that a person is prevented from “the danger of getting the disease and complications associated with it.”

For parents who remain in doubt about vaccination, Dr. Gatchalian said, “To do nothing is a greater risk than vaccinating.”