Did you know that PAGASA lists the coldest months in the Philippines as December through February? We like the cold because it is a nice change from the country’s oppressive heat, but we are also aware that this is the time of the year when weather-related illnesses like pneumonia are on the rise.

Respiratory diseases, like pneumonia, is common in cold weather, according to World Health Organization.

Pneumonia, a dangerous disease caused by bacteria, viruses, or fungi, can affect people of all ages, especially unvaccinated children. The chilly temperatures and low humidity levels can weaken the immune system and increase a person’s susceptibility to respiratory infections during the cold months.

The best method to avoid pneumonia is still to get vaccinated. This is in addition to maintaining good personal hygiene, avoiding direct contact with sick people, staying warm and dry, drinking plenty of fluids, quitting smoking, and maintaining a nutritious diet.

According to Dr. Maria Margarita Lota, chair of the Department of Medical Microbiology at the University of the Philippines’ College of Public Health, vaccination is one of the most effective ways to combat pneumonia, which is also one of the leading causes of death in children less than five years old.

“Being a pediatrician, we have to protect our children. As pneumonia continues to be a top cause of morbidity and mortality, we are fortunate that we are in an era where vaccination for many of these infectious diseases, like pneumonia, are available. Aside from proper hygiene and nutrition, vaccination is one of the most effective ways to prevent pneumonia.”

Right PCV against the Right Strains

In this context, Dr. Lota reinforced that a pneumococcal conjugate vaccine (PCV) should be suitable against local strains and backed up by sufficient real-world experience before being introduced in the National Immunization Program (NIP).

Dr. Lota gave her expert opinion on factors that should be considered before implementing a PCV under the NIP. Alongside cost-effectiveness and programmatic characteristics, she reinforced that a PCV should be suitable to protect against strains that are prevalent in the Philippines.

“One of the things that we really have to look for when we are considering the inclusion of a particular PCV in the NIP is your serotypes. ‘pag alam natin kung ano yung mga nag-eexist na serotypes in the community, we have to directly target these serotypes, or if not directly, ensure that there are reports of [this PCV] doing cross-protection,” she remarked.

In 2020, the Health Technology Assessment Council (HTAC) of the Department of Health (DOH), which is in charge of appraising health technologies that can be included for public use, recommended the use of PCVs protecting against 11 important strains which accounted for 48% of Invasive Pneumococcal Disease (IPD) cases found in the Philippines, namely: 1, 4, 5, 6B, 7F, 9V, 14, 18C, 19A, 19F and 23F. The recommendation was based on local surveillance data of the Research Institute of Tropical Medicine (RITM) from 2012-2019.

“By knowing which serotypes are circulating, kung meron naman ‘yong brands, this can already be used to prevent pneumonia significantly in the country. In the report that was made in 2019 by RITM, 48% of the circulating serotypes in the country can be addressed by currently available PCVs,” she remarked.

On the other hand, Dr. Lota also recognized the urgent need to improve surveillance of circulating strains of pneumonia in the Philippines.

“Different countries have different circulating serotypes. In our anti-microbial resistance surveillance program, they identified several serotypes causing pneumonia, but the problem with that was that there were low reports of isolates submitted to RITM. This becomes a barrier for us to really understand what are the prevalent serotypes in the country,” said Dr Lota.

Real-world Experience to combat Vaccine Hesitancy

Despite the availability of PCV in the National Immunization Program (NIP), a root cause to the still high number of cases of vaccine preventable diseases can be attributed to parents’ hesitancy to vaccinate their children, leading to less infants being brought to health facilities to be vaccinated against diseases like pneumonia.

“Unfortunately, even if we have all of these vaccines against pneumonia available in the NIP, it continues to be a burden of disease in many countries especially in low to middle income countries like the Philippines. The uptake of our vaccines is not very high because of the controversy of the dengue vaccine in 2016. Therefore, less babies are being brought to the health centers, so the consequence will be an increased number of pneumonia cases, one of the vaccine-preventable diseases that could have been prevented.”

To address this, Dr Lota highlighted that a PCV should have sufficient experience and accessible real-world evidence before being implemented in the Philippine NIP to address vaccine hesitancy.

“Accessible real-world evidence is connected to vaccine hesitancy. Even if we know that a vaccine can trigger a good immune response (“immunogenicity”), we need to still see if a vaccine is really effective when it is introduced in the community rather than just a sample cohort for instance. This will give confidence to parents that they can actually use this particular vaccine,” said Dr. Lota.

As a concrete example, Dr. Lota mentioned that we could learn from the slow acceptance of COVID-19 vaccines when it was first introduced in the Philippines.

“An example of this is your COVID-19 vaccine. In spite of being licensed and approved, many parents were hesitant during its release because it did not have enough data to show to the public. But if you have real-world evidence, which usually comes after the post-marketing, they will have more confidence that, yes, I can use this because it is safe and effective,” she added.

In October last year, HTAC released the final priority list of health technology topics that will be assessed for possible inclusion in the Philippine National Formulary (PNF), of which includes PCV.

Currently, there are three PCVs pre-qualified by the World Health Organization—PCV13 and 2 kinds of PCV10: PHID-CV and SIIL-PCV. The two PCVs that were reviewed by HTAC in 2020—PHID-CV and PCV13—were assessed as suitable to address the 11 important strains in the country.