How safe are vaccines? Can you mix and match vaccines? And how common are the side effects?

The Philippines first rolled out its vaccination drive over a month ago. Two vaccine brands and over 1.2 million administered doses later, many Filipinos are still apprehensive of getting inoculated against COVID-19.

The country has started inoculating its priority groups with jabs from either Sinovac or AstraZeneca, though the government temporarily stopped administering the latter to those under 60 years old after the European Medicine Agency found potential but very rare blood clotting side effect.

According to a recent Pulse Asia survey, 94% of Filipino adults are worried that they or any member of their household will get sick with COVID-19. But 61% of Filipinos refuse to be vaccinated with reasons such as: not sure of its safety, vaccine may not be effective, and the vaccine is not needed to combat COVID-19.

Despite assurances from health experts that the best vaccine is the vaccine in one’s arm, many are still saddled with doubt.

Recently, PhilSTAR Life, through its Vax to the Future virtual talk moderated by journalist Malou Mangahas, invited a panel of experts to answer some of the questions that continue to trouble Filipinos and contribute to vaccine hesitancy.

Are vaccines safe?

According to Dr. Nina Gloriani, head of the Department of Science and Technology vaccine development expert panel, the vaccines that have been approved by the Food and Drug Administration (FDA) have gone through stringent evaluation with several parameters that include safety, immunogenicity and efficacy.

Gloriani also said that the vaccines go through several processes, and at least three groups of experts are involved in the vetting process, namely the Department of Health (DOH), the interim national immunization technical advisory group, and the FDA.

Is it safe to mix and match vaccines?

So you already got your first dose of the vaccine, what if the supply runs out before your scheduled first dose? Can you be inoculated with a different brand of vaccine from the first one you received?

Gloriani said that as much as possible, the same platform and the same vaccine brand should be used. But in the event that problems arise like delays in arrival of the vaccines, they have to consider steps that should be taken in certain scenarios.

“Pinag-aaralan namin proactively ano yung posible natin gawin. Susundin ba natin yung ginagawa nila sa ibang bansa na nag-mi-mix-and-match sila? Pero on our own, titingnan natin yung kundisyon natin dito, but we are proactively looking into that bago ma-delay.”

Meanwhile, Dr. Anna Lisa Ong-Lim, member of the DOH and IATF technical advisory group, said that the deployment of the priority groups (frontline healthcare workers, A1; senior citizens, A2; and people with comorbidities, A3) is planned based on the availability of the vaccines. She assures that “everybody will have their second dose at the time that they are required to receive it.”

“Yung mga intervals natin for vaccines, mayroon naman po siyang allowance. Kung lumampas siya sa minimum interval, ok lang naman,” emphasized Lim, who also explained that schedules are given to those who are eligible to be vaccinated so the vaccine rollout would remain systematic.

But the panel of experts, including UP-PGH infectious disease specialist Dr. Regina Berba, maintained that even though there is an allowance in the vaccine interval, those who have been scheduled for their second dose should show up and not let their opportunity to be fully vaccinated go to waste.

How common and what are the usual side effects?

According to experts, it is common to experience side effects when one has been vaccinated, and those that are usually reported fall under mild to moderate. Side effects include pain, a bit of swelling, and itching on the vaccinated region. There are also flu-like symptoms and headache.

There are possible serious adverse effects like severe allergies to the vaccine. With this, Lim stressed the importance of stringent screening of patient profiles before they get vaccinated to identify those factors.

After one is fully vaccinated, when will one get immunity from COVID-19?

There are reports that COVID-19 still infected people who are already vaccinated. According to Lim, it is possible that one can still be infected as the body is just starting to build its protection against the coronavirus after vaccination.

Gloriani explained that the body takes a few weeks to build antibodies after vaccination. Upon receiving the first dose of the vaccine, that’s when the body starts to initiate an immune response but Gloriani said at that point, it is not yet safe to say that it is completely protective.

A few weeks after getting the second dose, that’s when it is expected that the body has enough protection but still, one has to wait about a couple of months for the full protection to set in, said Gloriani.

“Itong mga bakunang ito, ang sinasabi pa lang sa datos natin ngayon is nakaka-bawas siya ng severity ng sakit. Pero hindi tayo sigurado kung nakakapigil siya ng panghawa at panghahawa. Kaya kahit bakunado na, dapat meron pa ring protection,” Lim noted.

What's the word on Ivermectin and Lianhua Qingwen?

In the Philippines, Ivermectin is registered as an anti-parasitic drug, which is intended for use on animals and is not approved to treat any viral infection, according to the FDA. The DOH also does not recommend the use of Ivermectin for the treatment of COVID-19.

Meanwhile, the World Health Organization said the current evidence on the use of Ivermectin to treat COVID-19 patients is inconclusive and that the parasitic drug be used within clinical trials only.

The panel of experts, who echoed what the FDA, DOH and WHO said, believes that recommendation of potential treatments for COVID-19 should be backed by science and generating data should be scientific.

“Ang DOST and FDA, nanghingi ng anim na clinical trials (for Ivermectin). Ang conclusion nila (based on several parameters), walang datos na nagsasabi na may clear benefits ang Ivermectin,” Gloriani said.

On herbal product Lianhua Qingwen, Gloriani noted that it is a registered herbal supplement approved by the FDA but is not registered as a COVID-19 medication.