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How long will the vaccines protect you? (and other questions people often ask about COVID)

By DR. CHARLOTTE M. CHIONG, The Philippine STAR Published Jun 01, 2021 6:00 am

We are now 14 months into this COVID-19 pandemic, and life as we know it has totally changed. Akin to a world war, no country has actually been spared from the devastating effects on healthcare, social and economic well being of people.

We have experienced so much grief and suffering from losing friends, family members and so many healthcare frontliners in this very long saga that has afflicted almost 1.2 million Filipinos with about 20,000 deaths.

SARS-CoV-2 virus is the common enemy. We have all been familiar with viruses like influenza, dengue and HIV. We have heard of the Spanish flu in 1918 to 1919 that killed over 50 million people all over the world, the Philippines included.

Amazingly, as reported inScience,evolutionary biologists have recently been able to extract fragments of the RNA of the influenza virus from the formalin-preserved lungs of three teenagers (two soldiers and one civilian girl) from the Berlin Museum of Medical History and the pathology collection of the Natural History Museum of Vienna.

Getting a COVID-19 vaccine is the only way that the elderly, who are most at risk of dying from the virus, can be protected. Photo by WALTER BOLLOZOS

The virus that came from birds and jumped to humans underwent adaptation as evidenced by genome sequence changes and help explain why there were more deaths in the second wave of the flu pandemic 100 years ago.

In the future, scientists will look at this pandemic to derive lessons to also better deal with another pandemic, as this will certainly not be the last one. 

In the future, scientists will look at this pandemic to derive lessons to also better deal with another pandemic, as this will certainly not be the last one.

Over the past 52 weeks at exactly 12 noon every Friday, “Stop COVID Deaths” webinars can be viewed on the TVUP.PHFacebook page. This is organized by the University of the Philippines under the Office of Vice President for Public Affairs Elena Pernia, TVUP executive director and former UPOU chancellor Gigi Alfonso, as well as University of the Philippines Manila Chancellor Carmencita Padilla and PGH director Gerardo Legaspi.

Through this platform our faculty from the UP College of Medicine and invited experts from the Department of Health and other medical centers have been able to reach more than 100,000 participants. Ably hosting were the President’s special envoy for global health Susan Pineda-Mercado and National Institutes of Health-National Telehealth Center director Raymond Sarmiento.

Some of the frequently asked questions on COVID-19 were tackled and I included a few in this article:

What is this virus, its origins and why is it so transmissible?

SARS-CoV-2 is the virus that causes COVID-19. It is a highly transmissible and pathogenic betacoronavirus that shares genome sequence similarity with SARS-CoV (intermediate host palm civets) and MERS-CoV (intermediate : host: camels) at 79 percent and 50 percent, respectively.

As pangolin coronaviruses share no more than 92 percent genome identity with SARS-CoV-2, we cannot as yet declare pangolins as the real intermediate hosts. Gain of function experiments in laboratories like the Wuhan Institute of Virology have become an intense matter of debate.

The key to the high transmissibility of this virus is its ability to bind more effectively to cells (with ACE2 receptors) and with mutations leading to variants that render them hardly recognizable by the immune system.

How are they transmitted?

It is now evident that there are three major modes of transmission.

It is primarily airborne, inhaled through the nose and through deposition of infectious droplets on the exposed mucous membranes of the mouth, nose and eyes. A third mode of transmission is by touching mucous membranes with hands contaminated with virus-containing respiratory fluids.

Wearing a mask and face shield, washing hands often for at least 20 seconds, keeping a three-to six-feet distance and not staying in poorly ventilated rooms constitute the minimum health safety protocols that we all must follow.

If I get infected will I always have symptoms of fever, dry cough, muscle aches and headache?

Not all people manifest symptoms even if they are infected and about 20 per cent may remain asymptomatic and spread the virus unknowingly. This is the reason why everybody needs to practice the minimum health standards mentioned above.

If I get fever, does it mean I have COVID? When should I go to the hospital?

Not all fevers will be caused by COVID-19, as there are other infections like dengue, bacterial infections from the ear, nose, throat and other infections that can all cause fever. Fever may or may not be present, so if in doubt it is better to seek medical help by teleconsultation or one may reachPGH Telegabayin the PGH Facebook page for guidance from volunteer physicians.

If one is exposed to someone diagnosed to have COVID-19, there is a need to quarantine right away. If confirmed positive, one needs to isolate in a room preferably with its own toilet and bath, get packed meals with separate utensils so as to protect other household members from being infected. If one has difficulty in breathing with oxygen saturation (measured with a pulse oximeter) of less than 94 percent and breathing of more than 30 per minute (respiratory rate), then hospitalization is needed.

What type of testing should I get to confirm if I have COVID-19?

The best diagnostic test is a Nasopharyngeal/ Nasal/ Oropharyngeal Swab RT-PCR (Reverse Transcription-Polymerase Chain Reaction). Depending on the lab, one may get the results within 24 to 48 hours.

The Philippine Red Cross has been offering alternative tests that have been validated, such as the saliva RT-PCR test that we researchers at UP-PGH helped develop. The latest and special PGH issue on COVID-19 of Acta Medica Philippinaalso featured the “snort- spit saliva” specimen as a good alternative to nasal swab RT-PCR and found superior to rapid antigen testing.

Is there any treatment that works?

So far there has been clear evidence that corticosteroids like dexamethasone help in preventing death and enhancing recovery in hospitalized COVID-19 patients.

According to the Living Recommendations on COVID-19 of the PSMID (Philippine Society of Microbiology and Infectious Diseases) led by Dr. Marissa Alejandria, some treatments have been found to be either ineffective or with insufficient evidence like hydroxychloroquine/ chloroquine, convalescent plasma therapy, remdesivir, favipiravir, and colchicine, among others.

In the case of remdesivir there were published reports in NEJMthat it was superior to a placebo in shortening time to recovery in hospitalized adult patients, but a few days ago the WHO removed it from their list of medications for COVID-19.

Other treatments remain controversial like Ivermectin, a known antiparasitic drug that has been very effective in the treatment of river blindness (onchocerciasis). An in-vitrostudy by Caly and colleagues on the antiviral properties of Ivermectin last year primarily led to several studies on its use among COVID-19 patients. For regulatory bodies to approve its use, more evidence is being required.

Protocols for home care for COVID-19 have been developed as most hospitals in the NCR have become fully occupied. However, those patients with difficulty in breathing and O2 saturation of less than 94 percent are advised hospitalization for oxygen support usually given through high-flow nasal cannulas and treated with antibiotics, steroids, and anticoagulants to prevent further deterioration.

Monoclonal antibodies (e.g. bamlanivinab and etesevimab) are still being studied, similar to potential medications for non-hospitalized patients like molnupiravir in clinical trials.

What is the best strategy to get to a new normal?

Vaccination is seen to be the way out of this pandemic and we are aiming for herd immunity to be achieved by complete vaccination of about 70 million people in our country. The number needed for this herd immunity really largely depends on the efficacy of the vaccines used, given that our country will roll out multiple vaccine platforms. One advantage of a quick rollout is that this prevents escape mutations that may lead to the development of variants of concern.

Should I get vaccinated if I am already old?

Yes, in fact this is the only way that the elderly who are at most risk of dying from the virus can be protected. The immunosuppression commonly seen in elderly individuals may result in lower protection from the vaccine (lower vaccine efficacy).

Can I get vaccinated if I had allergies in the past?

Yes. Only allergies to polysorbate and polyethylene glycol found in vaccines will render one probably ineligible for vaccination. To be sure, one needs clearance from a board-certified allergologist, especially if an immediate allergic reaction developed after the first dose of any COVID-19 vaccine or if a severe allergic reaction developed after administration of any other vaccine.

Those with allergies not related to vaccination such as allergy to food, oral medications or pet dander, can be safely vaccinated. Those with a history of severe allergic reaction due to any cause should be observed for 30 minutes following vaccination.

Can I be vaccinated even if I am pregnant?

Yes, pregnant women in the second to third trimester can get vaccinated. There is even evidence that antibodies that protect against COVID-19 can be transferred to the fetus. The same is true in natural infection from COVID-19.

Neonatologist Dr. Karen Puopolo, in a recent paper published inJAMA Pediatrics, showed that SARS-CoV-2 IgG antibodies were present in the placentas from 87 percent (72/83) pregnant women who got infected. The levels in the umbilical cord blood were high, as was the mother’s antibodies. Also, the longer before delivery that the mom had the infection (at least 17 days), the greater the abundance of antibodies.

Which vaccine is the best?

The first vaccine that becomes available to you is the best vaccine.

None of the vaccines are 100-percent effective in protecting against disease. However, all vaccines available achieve what they most need to do and that is, prevent severe disease and death.

The most important goal in vaccination is the prevention of severe COVID-19 that can result in death. All COVID-19 vaccines issued with Emergency Use Authorization (EUA) by the Philippine Food and Drug Administration (FDA) are safe and effective based on the available evidence.

Before a vaccine can be issued with an EUA, it has to undergo rigorous evaluation processes involving the Department of Science and Technology, FDA, and various vaccine expert groups.

In this regard, Sinovac, Gamaleya-Sputnik, Oxford/Astra Zeneca (AZ), Pfizer/BioNTech, Moderna, Bharat BioTech, which all require two doses (three to 12 weeks apart between the first and second dose) and the soon-to-be- available Janssen/Johnson and Johnson, which will be a single dose, have all been issued Philippine FDA EUA approval. The EUA terms and conditions can be updated as more clinical trial data become available.

Can I have another vaccine brand even if my first vaccine dose is of a different brand?

It is not recommended to mix different vaccines. One gets protection two to six weeks after the single dose Janssen/J&J vaccine, while for the other vaccines administered in two doses, one gets initial protection two weeks after the first dose and full protection around two weeks after being given the second dose or full vaccination.

There are ongoing studies regarding “mix and match” vaccination but what is clear is that if one develops an allergic reaction to a first dose of a particular vaccine then the second dose can be skipped and one can instead opt to have another vaccine type. It is best to seek the opinion of a board-certified allergologist about questions regarding allergy to vaccines.

Is it true that some vaccines may really not be that effective?

None of the vaccines are 100-percent effective in protecting against disease. However, all vaccines available achieve what they most need to do and that is, prevent severe disease and death.

People with impaired immune response, the elderly, or those taking immunosuppressive drugs may not be able to develop a strong antibody response as compared to healthy vaccinated individuals. Vaccine effectiveness may also be affected by vaccine storage and transport, vaccine administration and other external factors.

In addition, consider the emergence of new variants. Poor border controls may still allow entry of people with variants of the virus that are not only more transmissible or more virulent, but may render certain vaccines less effective. Surveillance to detect variants of concern is performed by the Philippine Genome Center. There is clear evidence that asymptomatic carriers will unlikely infect those who have been fully vaccinated so we aim for this herd immunity, but until then we all need to follow public health safety protocols.

Is it bad for a person who does not know he already had COVID-19 (asymptomatic) to get a vaccine?

If one had a history of exposure to COVID-19 but did not develop symptoms then one can get vaccinated after the 14-day quarantine period. It may very well be that there are persons in vaccination areas that have had COVID-19 and are asymptomatic so that the minimum public health and adequate ventilation and safety standards are followed with DOH inspection of these sites a norm.

Do vaccines have an expiry?

The protection from a full-dose vaccination has been proven to last for six months but may even be longer. Using neutralizing antibodies as a marker of protection may not give the whole picture.

The CDC (Centers for Disease Control) in the US has come up with guidelines that there is no more need for masks after full vaccination. Can I unmask already once fully vaccinated?

The same guidelines released clearly states that government mandates whether national or local will still need to be followed. Vaccination should be viewed as just one part of a comprehensive package of COVID-19 prevention strategies, and this must be used in conjunction with other evidence-based public health measures.

Thus, when in a public place one has to still wear masks and face shields and avoid crowded or poorly ventilated areas even after being fully vaccinated. Based on the latest data, less than2.5 percentof the country’s population have received the first of two doses of the vaccine.

Meanwhile, those who have taken both jabs represent around0.72 percentof the population. This means that a huge majority of the population remain unvaccinated. Until the country achieves its target of vaccinating at least 70 percent of its population, we will need to continue following the minimum health standards even after receiving full vaccination.

This global pandemic will need a massive equitable vaccination strategy on top of maximal suppression of viral spread through sustained public health measures. The bayanihanspirit of the Filipino has been truly an inspiration. Science will surely be able to provide solutions, but solidarity will need to be stronger as vaccination with continuing health safety measures should be pursued.

Finally, I really believe our faith in God will provide the best way out of this pandemic.