in the Philippines
Vaccine Types • Ingredients • Ivermectin Conundrum • Mix & Match • Variants

Godofredo U. Stuart MD


In April 2020, when COVID-19 was proclaimed a pandemic, it jump-started the warp-speed global race to develop a vaccine. (According to estimates, there are more than 170 vaccines in trials.)  The vaccine was to be the silver bullet in the war against COVID. But the months of waiting were punctuated by vaccine trial pauses and cautionary reports that fueled doubts, fears, and hesitancy. It delighted the anti-vaccination bloc who found a new vaccine to wage war on, which it is, at present, winning in various population sectors.

Vaccine hesitancy is a global health challenge. While vaccination is one of the most effective ways of avoiding disease—it prevents 2-3 million deaths a year, and a further 1.5 million can be avoided with improved global vaccination programs—vaccine hesitancy threatens to reverse gains achieved by vaccination programs. (4)


While vaccine hesitancy is a global crisis, the Denvaxia fiasco boosted the deep and lingering distrust of vaccine science.

Post-Dengvaxia, there was a resurgence of measles with 42,000 cases, 3x the previous year, with over 500 deaths, up from 128. There was an outbreak of polio, two decades after WHO declared the country polio-free. Diphtheria jumped to 167 cases with 40 deaths, compared to 122 and 30 in 2018.

Sadly, it is a dismal failure of education and information dissemination of veritable information on the life-saving and health promoting benefits of a panoply of vaccines in use i.e. measles, mumps, polio, diphtheria, pertussis, tetanus, influenza, pneumovac, HPV, rabies, and hepatitis B, along with other essential travel vaccinations.


The Dengvaxia Role
The WHO vaccines advisory group identified complacency, inconvenience of access, and lack of confidence as key reasons for hesitancy. In the Philippines, the Dengvaxia fiasco of 2017 with its well-publicized finger-pointing and televised political hearings added high-octane fuel to vaccine hesitancy. This was compounded by a dismal failure of damage control with information dissemination to stress the disease prevention and life-saving benefits of all the other vaccines in use. As a consequence, there was a decline in vaccinations, with measurable upticks in the cases of measles, pertussis, and diphtheria. Unfortunately, this distrust continues into the COVID19 crisis into a hesitancy that threatens public health objective to achieve herd immunity through vaccination.

In the urban-suburban population, vaccine hesitancy from the Dengvaxia fiasco is not openly expressed. In the rural areas where vaccination rejection is widespread, the common response on why? is: Ayoko pang mamatay. . . gaya ng sa Dengvaxia.

As phobias are defined, COVID-19 vaccinophobia is an irrational fear. While vaccination is more readily accepted by the Generation X, vaccine resistance is widespread among the aging Baby Boomers, many suffering through sleepless nights or fitful slumber, terrorized by the fear of dying from the vaccine jab.

Taken in context, one is more likely to be hit by a lightning—1 in 500,00 to 1 in 1 million—than to die from a vaccine shot. The US National Weather Service puts the odds at 1.222.000 to be struck in any given year (estimated deaths + injuries), and 1 in 15,300 lifetime odds of being struck by lightning (Est. 80 years). (3)

While more mundane concerns compound vaccine hesitancy—confusing guidelines and advisories, limited vaccine access, the warp-speed vaccine development, it is the pipeline of the anti-vaccine movement, social media platforms and chat groups serving a smorgasbord of misinformation, conflicting news, and confusing advisories that contributes immeasurably to vaccine hesitancy.

It is the recent social media addition to vaccine patois—vaccine envy, typically Filipino, gaya-gaya-puto-maya or sige-na-nga, ako na rin—to explain a recent surge in vaccination jabs.

Like many Third World countries, the Philippines does not have the luxury of choice. At present, it is SinoVac or AstraZeneca, still in rather limited and erratic supply. Grapevine tells of the coming availability of Pfizer, Moderna, Gamaleya (SputnikV).

What is the Best Vaccine?
Vaccination is still the most effective way of preventing infection in the individual and in the general population. Vaccination diminishes severe life-threatening disease to moderate disease, moderate to mild, and mild to asymptomatic. While the vaccines have different levels of efficacy, all the COVID-19 vaccines prevent death and severe disease.

In the absence of choice, and with limited and erratic supplies, the best vaccine is: WHATEVER IS AVAILABLE. For now, they are Sinovac and AstraZeneca, the two main vaccines approved by the FDA for the country's inoculation campaign—Sinovac with 50.4% efficacy or Astrazeneca with 62-90% efficacy. For developing countries, they are the two most useful with the advantage of storage in standard refrigeration. (see box below)

Vaccine science is in flux. All the vaccines in use were approved for "emergency use." All are in continuing trials and surveillance studies that will eventually resolve current safety issues and concerns. Some could end up being shelved, while new ones can emerge with better efficacy and safety profile. Pfizer's ongoing trial indicates its two-dose vaccine remains highly effective for at least six months, likely longer. Moderna also claims notable levels of antibodies six months after the second dose.

While the list of vaccines continues to grow, and the selling points of where they were made and efficacy ratings make one more attractive than the other, there is the danger of getting COVID and dying while waiting for the "better" vaccine.

The diehard AntiVacs have embraced ivermectin as their magic bullet for prevention and disease treatment. For the ProVacs who started on ivermectin while waiting for the vaccine, should the IVM be continued after vaccination? While ivermectin lingers in limbo, awaiting the results of clinical trials that will endorse preventive or therapeutic use or debunk it, the decision to continue is a personal decision guided with modicum of science. If IVM was started on the belief of its preventive or therapeutic efficacy, in the face of uncertainty in the vaccines duration and degree of efficacy, the rising threat of variants and effect on vaccine efficacy, the possibility of re-infection or failures—then continuing ivermectin in a preventive dose is a viable option.. (see: ivermectin3)

Mixing and Matching Vaccines (M&M)
• Supply chain issues raised the question that potentially allowing people to use different vaccines may help people get vaccinated more quickly.

• Because of lack of available safety data, experts suggest COVID-19 vaccines shouldn't be mixed unless there is an "exceptional situation", like shortage of the vaccine the person first received.

• In a pneumococcal model of Streptococcus pneumonia, which can cause pneumonia, bloodstream infection, meningitis, etc, use of two different types of pneumococcal vaccines with different mechanisms of action have been used to boost the vaccination effect. The models of two vaccines is being looked at as a COVID-19 vaccination option.

• Trials: There are two trials underway. One, a mixed vaccine trial, examining a matching dose of Sputnik V vaccine made by Russia's Gamaleya Institute with AstraZeneca. The other trial, known as Com-Cov, a combination of AstraZeneca-Oxford as first dose followed by Pfizer-BioN Tech vaccine, or vice versa, mixing two different technologies. Until results are out, the US CDC discourages the mixing of vaccines unless there are "exceptional situations" such as shortage of the initial vaccine received. Indeed, the scarcity of COVID-10 vaccines and the urgency of ramping up vaccination rates have brought the option of mix-and-match to the fore. Having interchangeable products at vaccination disposal will boost vaccination efforts in the setting of uncertain supplies. (8)

Commonly Asked Questions and Concerns
Post-Vaccination Infection:
• Rare, but not impossible. None of the vaccines are 100% effective. Even the touted 95% efficacy of the mRNA vaccines, suggests 1 in 20 could still develop COVID19. The 5% who can become infected are unlikely to get hospitalized. Prevalence and the individual's immune system can be factors in reinfection.

• In a BioNTech/Pfizer study done in the US, Europe, South America and South Africa, there were nine cases of COVID at least 7 days after the second dose among 19,965 recipients and 169 among 20,192 placebo recipients.

• Post-vaccination infection may occur in those with compromised immune systems.

• Post-vaccination infection can be caused by vaccine failures due to a bad batch from manufacturing defect or a cold chain break during transport of that particular batch.

COVID-19 Reinfection
• Reinfection refers to a person who was infected, got sick, recovered, and got infected again. Yes, reinfections are expected and have been reported. Studies are on-going, evaluating frequency, severity, predisposing risk factors, and impact of Covid-19 vaccines. Studies suggest at least a six-month period of immunity to reinfection. An early study by Public Health England showed 83% protection against reinfection over a five-month period. Out of 6614 participants, 44 had "possible" or "probable" infections. (12) (13)

Can you spread COVID after vaccination?
• Studies suggest that while vaccines do reduce transmission after vaccination, inoculated peope can still pass the infection to others. The vaccinated should continue the mitigating protocols of masks, distancing, and handwashing.

Side effects:
• Side effects are common, but usually mild to moderate. At the injection site, it is not unusual to have pain, redness and swelling. A cool compress over the area may help; using or exercising the arm is not prohibited. Generalized side effects may include fever, tiredness, chills, nausea, muscle aches, and headaches. Over-the-counter medicines that you have taken before, like ibuprofen, mefanamic acid, paracetamol, or aspirin, can help relieve this short-lived effects. Some of the medicines can upset the stomach and should be taken with food. Consult your doctor if you have had previous problems with them.

• Side effects such as fever, chills, tiredness and headache are more common after the second dose. A small number may have severe side effects to the point of affecting abilities for usual daily activities.

• Severe and immediate allergic reactions are refered to as anaphylaxis, Severe side effects are difficulty breathing, swelling of face and throat, fast heartbeat, generalized rash, dizziness and weakness. Such patients may require treatment with epinephrine or EpiPen or hospital emergency care.

All people who get vaccinated should be monitored on site for at least 15 minutes. People with a history of severe allergic reactions or any type of immediate allergic reacton to a vaccine or injectable therapy should be monitored for at least 30 minutes after getting the vaccine.

Patients who experience a severe allergic reaction after the first shot, should not get second shot of the same vaccine.

Vaccines and Clots in the Brain:
• The US Federal health officials put a halt on the Johnson & Johnson (J&J) vaccine after six women developed blood clots (cerebral venous sinus thrombosis / CVST) in their brains up to 3 weeks after vaccination The cases were similar to those seen in European countries by the AstraZeneca (AZ) vaccine. J&J and AZ are similar in that both use an adenovirus vector to induce immunity to the Sars-CoV-2 surface protein, but they use different adenovirus vectors. The J&J uses a human adenovirus while AZ uses a chimp adenovirus. The 6 cases occurred after 7 million J&J vaccination—a risk so extremely low at one in a million. (9)

• France's health regulator recommends people under the age of 55 who received a first dose of AZ should get Pfizer or Moderna for a second dose, with a gap of 12 weeks. Germany follows a similar advice: age under 60 should get AZ as first dose followed by a different vaccine for 2nd dose.

Who should not get the COVID-19 vaccine?
• Most should get vaccinated. A few groups should not get the vaccine or get a particular version. People with a history of severe allergies or known allergies to vaccines ingredients should consult their physician for advice on alternative choice. Most vaccines are advised for age 16-18 and above. People in isolation or experiencing COVID symptoms should delay vaccination until after isolation or symptoms have resolved.

• mRNA vaccines should be avoided by people with a history of severe or immediate anaphylactic reactions to a COVID-19 mRNA vaccine dose or component or a known allergy to polyethylene glycol. They may be able to get the J&J and AZ vaccines

• Adenovirus vaccines (J&J, AZ, Sputnik) should be avoided by people with previous severe or immediate allergic reaction to COVID adenovirus vaccine or one of its components. They may be able to get the mRNA (Pfizer and Moderna) vaccines.

• Risk vs Benefit: There are patient groups that should weigh risk-vs-benefits and consult with their physicians. Patients with a history of severe or immediate allergic reactions to one of the vaccines and who are uncertain as to what component might have caused the reaction should consult an allergist or immunologist. Other patient populations of concern are pregnant and breastfeeding women, people with certain immune-compromising conditions, and people on anticoagulants. (9)

Do the COVID-19 vaccines shed virus or replicate?
• None of the vaccines (Moderna, Pfizer, AstraZeneca and J&J) are live weakened versions (Live attenuated vaccines that are weakend form of virus that can replicate without causing illness like the measles, mumps, rubella or chicken pox vaccines. Moderna and Pfizers are mRNA vaccines, while AZ and J&J are non-replicating vectored vaccines. THEY DO NOT SHED. (9)

Variants effect on transmissibility and disease severity
• As the virus spreads and replicates, the likelihood of mutation increases. Depending on where the changes occur in the virus's genetic structure, properties like transmissibility and virulency increase. Mutations may also reduce the efficacy of existing vaccines.

• COVID-19 virus has been mutating at a rate of 1-2 mutations per month, with some accumulating significantly more mutations in short periods of time. The variants raise questions and concerns regarding increased transmissibility, increased virulence, immune escape, and their effect of current molecular diagnostic tests.  (10)

• Variants identified: UK, B.1.1.7.; South African, B.1.351; Brazilian/ Amazonas, P.1, P2; California or West Coast, B.1.429, B.1.427; Nigerian, B.1.1.207; Ugandan A.23.1; Columbus or Ohio, COH. 20G/501Y; New York B.2.525, B.1.526; Philippines P3; Indian B.1.617. Some of the variants have shown increased transmissibility and increase disease severity, some have shown potential for immune escape and possible effect on vaccine efficacy. The Philippine variant is considered potentially more transmissible, with no evidence of increase disease severity and still unknown effect on vaccine efficacy or immune escape. (11)

Vaccine Type  
Whole Virus

• Many conventional vaccines use whole viruses to trigger an immune response.

• Live Attenuated Vaccines (LAV): Use a weakened form of the virus that can replicate without causing illness. Examples: Live attenuated vaccines against viral infections include MMR (measles, mumps, rubella), Cpwpox, Yellow Fever, Influenz (intranasal vaccine) and oral polio vaccine. Live attenuated vaccines against bacteria include tuberculosis, BCG, and oral typhoid vaccine.

• Inactivated Vaccines (IV): Use viruses whose genetic material has been destroyed so they cannot replicate, but can still trigger an immune response. LAV may cause disease in people with weak immune systems; require cold storage, challenging in low resource countries. IV can be used in people with compromised immune system, but may still need cold storage. Examples: Inactivated polio virus (IPV) vaccine, whole cell pertussis (whooping cough) vaccine, rabies vaccine, hepatitis A virus vaccine.
Protein Subunit

Protein subunit vaccines: Unlike inactivated whole-cell vaccines, they do no contain live components of the pathogen. They contain only antigenic parts of the pathogen, often fragments of protein, which are necessary to elicit a protective immune response, albeit weaker. They require adjuvant to help boost the immune response. Example: Hepatitis B vaccine.

Nucleic Acid

Nucleic Acid Vaccines (NAV): Use genetic material—either RNA or DNA—to provide cells with instructions to make the antigen to covid19, it is the spike protein. once the genetic material gets into human cells, it uses our cell's protein factories to make antigen that will trigger an immune response. These vaccines are easy to make, and cheap. RNA vaccines need storage at ultra-cold temperatures, -70*C or lower, challenging for countries without specialised cold storage equipment.

mRNA vaccines: cannot give someone COVID19; do not use live viruses; do not affect or interact with DNA in anyway; does not enter the nucleus of the cell where DNA genetic material is kept. Not new, has been studied for decades, using readily available materials.

mRNA vaccines have elicited potent immunity against infectious disease targets in animal models of influenza virus, Zika virus, rabies virus, and others using lipid encapsulated or naked forms of sequence-optimized mRNA.


Viral Vector

Viral Vector Vaccines (VVV): Uses genetically modified virus. The vaccines give cells genetic instructions to produce antigens. It differs from NAV in that they use harmless virus, different from the one the virus is targeting, to deliver the instructions into the cell.

Example of a vector virus is adenovirus, which causes the common cold. as with NAV, our own cellular machinery is hijacked to produce antigen from the instructions to trigger an immune response. VVV can mimic natural viral infection and should trigger a strong immune response. However, previous exposure to the viruses being used as vectors may make the vaccine less effective because of immunity to it. (1)

Vaccine Age Shots needed Full vaccination Type
Pfizer-BioNTech 16 yrs and older 2 shots
3 weeks apart
2 weeks
after 2nd shot
Moderna 18 and older 2 shots
4 weeks apart
2 weeks
after 2nd shot
Johnson & Johnson 18 and older 1 shot 2 weeks
after the shot
Viral Vector
AstraZeneca   2 shots   Viral Vector
Corona Vac / SinoVac   2 shots
3 weeks apart
  Inactivated Virus
Sputnick V   2 shots   Viral Vector
Novavax       Protein-based
Janssen (info pending)     Viral Vector


Vaccine Characteristics & Ingredients Storage Effectivity

• Part of the coronavirus' genetic code is injected in the body to give the immune system instructions on how to replicate viral proteins, harmless pieces of the virus molecule that will trigger the production of antibodies to fight the coronavirus. The process does not change the DNA of a human cell.

• Active substance is BNT162b2RNA, the synthetically engineered messenger RNA (mRNA), which teaches the body to fight the coronavirus.

• Ingredients: mRNA, lipids (4-hydroxybutyl)azanediyl)- bis(hexane-6,1-diyl)bis(2-hexyldecanoate), 2 [(polyethylene glycol)-2000]-N,N-ditetradecylacetamide, 1,2-Distearoyl-sn-glycero-3- phosphocholine, and cholesterol), potassium chloride, monobasic potassium phosphate, sodium chloride, dibasic sodium phosphate dihydrate, and sucrose.

- 70°C 95%

• Part of the coronavirus' genetic code is injected in the body to trigger the body to produce viral proteins, not the whole virus, which the immune system is trained to attack.

• Ingredients: Messenger ribonucleic acid (mRNA), lipids (SM-102, polyethylene glycol [PEG] 2000 dimyristoyl glycerol [DMG], cholesterol, and 1,2-distearoyl-sn-glycero-3-phosphocholine [DSPC]), tromethamine, tromethamine hydrochloride, acetic acid, sodium acetate trihydrate, and sucrose.
• Does not contain eggs, preservatives, latex.
-20°C 95%

Johnson & Johnson



Ingredients: recombinant, replication-incompetent adenovirus type 26 expressing the SARS-CoV-2 spike protein, citric acid monohydrate, trisodium citrate dihydrate, ethanol, 2-hydroxypropyl-β-cyclodextrin (HBCD), polysorbate-80, sodium chloride. • Does not contain eggs, preservatives, latex.    
CoronaVac /

• A formaldehyde inactivated vaccine with alum adjuvant
• Uses killed viral particles to expose the body's immune system to the virus without risking a serious disease response.

• A more traditional method as used in well known vaccines like rabies, pertussis, inactivated polio vaccine.

• Trials published variable efficacies: Late-stage trials in Turkey and Indonesia showed 91.25% and 65.3% efficacy, respectively; Brazil, 50.4%.
Standard refrigeration at 2-8° Celsius. 50.4% (variable)

• Active ingredient is a non-infectious chimpanzee adenovirus, used as a delivery system for a DNA payload, which contains the code to produce SARS-CoV-2 spike protein, into the body's cells.

• The chimpanzee adenovirus is likely new to the general population. With a human adenovirus, there is a good chance of antibodies against it, which can neutralize the adenovirus before delivery of the DNA to the cells, and make the vaccine fail.

• Inactive ingredients include excipients histidine, histidine hydrochloride monhydrate, sodium chloride, magnesium chloride hexahydrate, disodium edetate (EDTA), sucrose, ethanol absolute, polysorbate 80 and water.

Regular refrigeration 62-90%



• An adenoviral-based, two-part vaccine against the SARS-CoV-2 coronavirus. It uses a weakened virus to deliver small parts of the pathogen and stimulate an immune response.

• Sputnik V is a vector vaccine based on adenovirus DNA, in which the SARS-CoV-2 coronavirus gene is integrated, The adenovirus is used to deliver the coronavirus gene to cells and start the synthesis of envelope proteins that will be recognized by the immune system as a potential enemy.

• The first shot leads to humoral cellular immunity, the second starts the formation of memory cells.

• The active components are modified replication-defective adenovirus of a different serotype—serotype 26 as first component and serotype 5 for the second—modified to include the protein S-expressing gene of Sars-CovV-2.

Ingredients include Tris-(hydroxymethyl)-aminomethane, Sodium chloride, Sucrose, Magnesium chloride hexahydrate, Disodium EDTA dihydrate, Polysorbate 80, Ethanol, and Water.

Regular refrigeration 92%
by Godofredo U. Stuart Jr., MD        • 0917 510 5949 • godofredo, •            April 2021
CDC / Centers for Disease Control and Prevention
GAVI: The Vaccine Alliance
How Dangerous is Lightning? / National Weather Service
Tenthreats to global health in 2019 / WHO
Overcoming Vaccinations Resistance / Laura LeBleu
Philippine disease outbreaks linked to vaccine fear / Paul Icamina / SciDev.Net's Asia & Pacific Desk
Can We Mix and Match COVID19 Vaccines? Experts Say Not Yet / Health News
Should you mix and match COVID-19 vaccines? Scientists are seeking answers / Jon Cohen / Feb 12, 2021 / Science
Questions and Answers about COVID-19 Vaccines / Children's Hospital of Phiadelphia
Coronavirus mutstions and variants—what do we know? / ThermoFisher Scientific
A Reference Guide to Notable SARS-CoV-2 Variants / ThermoFisher Scientific
What we know about covid-19 reinfections so far / British Medical Journal, Jan 2021 / DOI:
COVID-19 reinfection 'rare' says NHS study but some may still pasz the virus on / Emma Wilkinson / PULSE
Sputnik V Vaccine / VP Precision Vaccinations
Dr Godofredo Stuart • 0917 510 5948 • godofredo,
April 2021
by Godofredo U. Stuart Jr., MD
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