Decoding Vaccines and Antivirals

0:00:01 - Announcer

You are listening to the National University Podcast.

0:00:10 - Kimberly King

Hello, I'm Kimberly King. Welcome to the National University Podcast, where we offer a holistic approach to student support, well-being and success - the whole human education. We put passion into practice by offering accessible, achievable higher education to lifelong learners. According to PubMed Central, the development of safe and efficacious vaccination against diseases that cause substantial morbidity and mortality has been one of the foremost scientific advances of the 21st century. Vaccination, along with sanitation and clean drinking water, are public health interventions that are undeniably responsible for improved health outcomes globally. Today, we are talking about vaccines and how they work. On today's episode, we're discussing vaccines and what they are and how they work, and joining us is Dr. Huda Makhluf.

And Dr. Makhluf is a professor in the Department of Mathematics and Natural Sciences at National University and the Academic Program Director for the Associate Degree in Science for General Education. She earned her PhD in microbiology and immunology from the Medical University of South Carolina and conducted her postdoctoral research at Harvard Medical School in the Department of Orthopedic Surgery, before moving to Baylor College of Medicine. At National University, Dr. Makhluf teaches biology and microbiology for pre-allied health majors and collaborates with scientists at the La Jolla Institute for Immunology. She is a strong advocate for STEM and in 2016, while serving as Department Chair of Mathematics and Natural Sciences, she secured an innovation grant from the NU system to pilot next-generation learning and strategies to increase inclusive excellence and persistence in math and science. She also tested an artificial intelligence assessment and learning system to improve math and science literacy for students with diverse math and science backgrounds. Wow, so fascinating. We welcome you to the podcast, Dr. Makhluf. How are you doing?

0:02:21 - Doctor Huda Makhluf

I'm doing great. Thanks, Kim, for having me.

0:02:24 - Kimberly King

Absolutely Impressive here, and why don't you fill our audience in a little bit on your mission and your work before we get to today's show topic?

0:02:32 - Doctor Huda Makhluf

Sure, I'll be happy to. Again my mission as an educator in higher ed. My mission definitely aligns with the mission of our university, which is to deliver accessible, world-class student experiences by providing quality programs and services that ensure student success through meaningful learning. I always strive to provide my students with world-class education - meaning cutting-edge science discovery, and I get them excited about science. As a scientist, I try to instill in them the love of science and, as a lifelong learner myself, I also strive to provide them with opportunities that they can make a difference in this world. Currently I'm teaching a microclass here at National, here at Spectrum, and my students are discovering new antibiotic isolates from soil samples. So far we've discovered three promising antibiotic producers from various soil samples gathered here in Southern California.

0:03:37 - Kimberly King

Wow, I could probably talk to you all day, but your background is so fascinating and today we're actually talking about what vaccines are and how they work. And with your varied background and all of that education, Dr., what is immunization?

0:03:55 - Doctor Huda Makhluf

Okay, so let's start by clarifying any confusion: Immunization or vaccination? Immunization, according to the WHO, refers to the process of becoming immune to an infection, either by natural infection getting sick with chickenpox or by vaccination avoiding disease by getting the chickenpox vaccine. The CDC has a similar definition. Vaccination, simply put, is a safe and effective way of protecting ourselves against harmful diseases, that is, getting protected or immunized before we are exposed to the diseases themselves. So vaccination relies on our own immune system to create such a defense mechanism. Now for the details.

Vaccination is a process that begins by introducing our bodies with a weakened component of a disease-causing organism, and that is a pathogen, be it bacteria or a virus. And this introduction stimulates a protective response by our immune system without causing disease. So the overarching goal here is to educate the immune system and prepare it to recognize a specific invader in the future and defend it against that specific invader or pathogen. In this way the immune system, again, is able to prevent disease, at least severe disease. So one thing to remember the vaccination is not sterilizing. One still gets exposed to an infected by pathogens, but the vaccination process mitigates the symptoms or prevents the disease from happening altogether.

Vaccines typically contain antigens. These are particles of a pathogen that trigger the immune response when a person is vaccinated, and they again. There are two types of reactions when it comes to vaccination. One reaction stimulates our body's B cells. It's a special type of cell in the adaptive immune system. It secretes antibodies. Another reaction stimulates the formation of memory T cells. These are specific to this invader and these memory cells, as the name implies, memorize the structure of the pathogen, allowing the immune system to respond rapidly and effectively if the individual encounters this disease-causing pathogen in the future.

0:06:32 - Kimberly King

Wow, okay, thank you, it is very interesting and you explain it so well. Could you briefly explain the history of vaccination?

0:06:42 - Doctor Huda Makhluf

The history of vaccination is fascinating and continues to have a critical and huge impact on public health. The true birth of vaccination is attributed to Dr. Edward Jenner, an English physician of the late 18th century. In 1796, precisely, he observed the following: why did dairy maids, who, by the nature of their jobs, milking cows pull through the mild infection known as cowpox, but were also so well protected from the devastating smallpox? Jenner brilliantly came up with the hypothesis that a cowpox infection provided protection against smallpox. In other words, getting infected with cowpox was akin to getting a vaccination against smallpox. So in order to test his hypothesis, he conducted an experiment that would never be approved today. He inoculated the eight-year-old son of his gardener, little James, with cowpox fluid and later that year exposed him several times to the smallpox virus. Fortunately for all involved, James never developed smallpox. James has been vaccinated against smallpox. You see, the discovery led to the foundation of the smallpox vaccination, the world's first vaccine. 200 years later, on May 8th 1980, the world was declared free of smallpox and to this day, many consider this accomplishment public health's greatest international achievement.

Now, in the 19th century, Louis Pasteur paved the way for further vaccine development. Pasteur developed vaccines for anthrax and rabies after establishing another key principle in immunology, and that is using an attenuated or weakened version of a pathogen to create safe and effective vaccines through the same process employed by Jenner. Throughout the 20th century, many vaccines were continuously being developed against the myriad of infectious agents, including polio, measles, mumps, rubella, pertussis and tetanus, and, paralleling this success, mass vaccination with these new vaccines has significantly reduced the incidence of all these diseases. So the Global Polio Eradication Initiative had set a goal of ending all types of polio in 2023; unfortunately, because of wars and the COVID-19 pandemic, routine childhood vaccination programs have been disrupted and the effort lost ground. Nevertheless, our era also witnessed amazing innovations in vaccine technology, such as combination vaccines, recombinant DNA technology and mRNA vaccines, allowing for the creation of still safer and more effective vaccination.

0:09:59 - Kimberly King

Okay, and thank you, that is really interesting. And boy, you know just the history of the young boy that was inoculated. That's really fascinating. You know, sometimes it takes a moment for you to really kind of think about how did it start. So thank you for explaining that. So you talked a little bit about this in the very first answer and that is how do vaccines work? Is there a simple way to answer that?

0:10:23 - Doctor Huda Makhluf

Vaccines work by leveraging the most basic and essential principles of immunology and you can summarize them in four abilities and detect. So the person hosts immune response, detects and resists infection tool. Recognizes a person's own cells as self and rely on memory from previous exposures or infections and then limit a response, a person's response once the pathogen has been removed. So again, vaccination against a pathogen is different from getting an infection with the real pathogen. Vaccination trains and prepares the immune system, via a milder process, to effectively respond to potential future infections with the pathogen. So this includes, again, viruses such as measles and chicken pox and bacteria like streptococcus and MRSA. So the vaccine contains that foreign molecule, an antigen component, and it's derived usually from the target pathogen. The antigen is weakened or inactivated and this piece the antigen or this piece of protein for example the spike protein from SARS-CoV-2, once injected into our body, the antigen will be recognized by competent immune systems as non-self and it sets off a cascade of actions and reactions that neutralize that invader. This response is usually followed by immunological memory for future exposures. So, as such, receiving a vaccine is not going to cause the disease, it merely simulates an infection state that, if you may stimulate the immune system.

Let's illustrate with an example. If you get the flu vaccine, up to 15% of recipients will have a sore arm at the injection site or feel tired and feverish for one to two days. They don't get the flu. In contrast, getting sick with the flu can simply imply one to two weeks of high fever and chills, missing one to two weeks of work or school, then getting complications like pneumonia, especially in our most fragile populations - the elderly and children two and under. So in 2017, 2018, there was 52,000 deaths from the flu. In 2019 to 2020, about 25,000. So you see, vaccinations work. They bolster our immune system's ability to fight diseases and play a crucial role in reducing disease burden and alleviating suffering and pain.

0:13:15 - Kimberly King

Wow. Well, so this kind of leads me to my next question. So, Dr. Makhluf, the immune system defends our body against infectious diseases, but can you briefly describe the components of the immune system and then the type of responses?

0:13:31 - Doctor Huda Makhluf

Yes. So, as we've discussed, the immune system is a sophisticated defense mechanism that protects our bodies from infections and diseases. Most people think of it in terms of its microscopic components - a complex network of cells that include lymphocytes, T cells, B cells and natural killer cells, neutrophils, monocytes, macrophages and dendritic cells. But did you know that the skin is not only our body's largest organ, but an active part of our immune system? It's more than just a physical barrier between our internal organs and the environment, with all its toxins, pathogens and stressors. Skin care is therefore more than skin deep. So take good care of your skin - wear sunscreen, drink plenty of water, eat a healthy, balanced diet and, of course, get enough sleep.

Now let's get our microscopes out and focus on the molecular and cellular components of the immune system streaming in our bloodstream, blood vessels, lymphatics, spleen and tissues within the immune system. There are two types of responses: the innate immunity and the adaptive immunity components. In innate immunity, we just touched on briefly physical barriers such as skin, the mucus, membranes in our mouth and nose, stomach acid, etc. Let's focus on adaptive immunity. The adaptive immunity response involves many players, starting with phagocytic cells. These are specialized type of cells that ingest and digest pathogens. They include macrophages, antigen presenting cells. They process and present antigens for recognition by other cells. These cells are the cytotoxic, killer T cells that possess molecular weapons to directly attack the pathogens. Helper T cells, probably the most important component of adaptive immunity and they are needed to help both killer T cells and B cells and, yes, B cells or B lymphocytes, the cells that create antibodies to neutralize pathogens. It's tantamount to cell wars, just like Star Wars. These cells have a mission. Their mission involves four phases: encounter, activation, attack and memory, all against a wide range of pathogens. Let's discuss some of these cells in some detail.

T cells- they're a type of specialized cells in the immune system, further classified into two types the cytotoxic T cells, also known as CD8 positive T cells, and the helper T cells, known as the CD4 positive T cells. They have different functions, again, within the immune system and its overall response. CD8 positive or cytotoxic T cells are involved in what's known as cell-mediated immunity and their main function is to destroy infected cells with a virus or abnormal cells. So infected cells would be those cells infected, say, with a bacterium or a pathogen or virus, and abnormal cells would be cancerous cells in your body. They are named cytotoxic because they release toxic substances like perforin and granzyme. This process induces the death of the target cell by a process called apoptosis or programmed cell death. The CD4 positive T cells, on the other hand, are known as helper T cells. They do not directly kill infected cells but they provide instruction, support, and help to other immune cells and they help coordinate the activity of B cells, cytotoxic T cells, and other immune cells, so ensuring a well-orchestrated immune response.

And finally, the B cells - B cells are immune cells that produce antibodies. They are helped again and activated by helper T cells to multiply and differentiate into specialized cells called plasma cells. So these plasma cells are factories that produce buckets and buckets of antibodies, all specific to the disease, or vaccine antigen. So an antibody is a relatively large Y-shaped protein that circulates in the blood and is used by our immune system to recognize pathogens and neutralize them and block them. So the antibody production is important because without blocking these pathogens they can cause disease. So this is possible today, tomorrow and years and years later sometimes.

Again, it's possible through B cell memory formation, b cells become long-lived memory B cells. These memory B cells remember the pathogens, antigens, and they are stored for a long, long period of time in the body. So when a person encounters the actual pathogen later on, these memory cells kick in quickly, recognizing the invader and mounting this rapid and robust immune response. But sometimes this memory fades away and it will require a booster shot to reeducate the immune system so it can stay effective at recognizing the pathogen.

So for tetanus, the booster shots are needed every decade or five to ten years at least. For other vaccines the booster shots may be needed every two to six months. Example DTAP, diphtheria, tetanus and pertussis in children under five. So that's a lot. Let's recapitulate the main ideas. Just like its name suggests, the adaptive immune response is pathogen specific. It develops with every event, each event, and adapts over time. And it involves, as we've mentioned earlier, the B cell response, the humoral immunity and the T cell response, the cytotoxic mediated immunity. B cells produce antibodies that neutralize specific antigens, and T cells will kill an infected cell or a tumor cell. So, broadly speaking, the key functions are recognition, response and memory.

0:20:16 - Kimberly King

Great, wow. Yes, that is. There's a lot in there, but thank you for kind of really breaking that down. What is herd immunity?

0:20:24 - Doctor Huda Makhluf

So herd immunity, again, is a clever strategy in vaccination process. It is immunity at the level of a population. It provides indirect protection against the spread of infectious diseases, but only after a large enough portion of a community, the actual herd, becomes protected or immune to a disease. So to achieve herd immunity for a specific infectious agent, a significant portion of the population must become immune to this pathogen and the immunity can be the result of vaccination or artificial immunization or from natural immunization or natural infection. So herd immunity against measles requires about 95% of the population to be vaccinated. Only then will the remaining 5% unvaccinated people be protected. For polio the threshold is only 80%. To reach herd immunity for COVID-19, it's postulated that more than 70% of the population would need to be immune. It has also been debated that this concept of classical herd immunity may not completely apply to COVID-19.

So herd immunity again. When a significant number of individuals within a population become immune to that pathogen, the ability of this agent to spread, the virus to spread is limited. So herd immunity interrupts the transmission of the infectious agent and protects the vulnerable amongst us. So who cannot get vaccinated or are at high risk of succumbing to severe disease, like babies or infants too young to be vaccinated, or elderly individuals, people who is a weakened immune system. These people are shielded from exposure to the pathogen because many people in the community are vaccinated. So it's a way to stop the spread of an infectious agent and herd immunity, we have to remember, can change over time due to fading immune memory and waning immunity and the emergence of a new viral variants and escape mutants. So you see, the immune system never sleeps.

0:22:53 - Kimberly King

That is a good point. Okay, thank you for helping us to understand that. You mentioned viral variants. Can you explain what a virus is and what escape mutants are? And also, why do we need to stay up to date on vaccination? There's a lot in that, so I can re-ask you that if you need.

0:23:12 - Doctor Huda Makhluf

Right, that's a great question, Kim. Virus is a tiny infectious agent measured in nanometers. Viruses infect all life forms, from plants and animals to microorganisms living inside them, even bacteria, our own microbiome in our gut. So viruses are the most numerous type of biological entity and we're discussing here the type that make us sick, the viruses. In this 12 podcast this week in virology quips, it's about the viruses that make you sick.

So viruses consist again of genetic material, either DNA or RNA, encased in a protein coat. We usually call it a capsid. And some viruses have an outer lipid envelope and we call them enveloped viruses. HIV, the virus that causes AIDS, or SARS, cov-2, the virus that causes COVID-19, are enveloped viruses.

And viruses, again, cannot replicate on their own, nor can they carry out their life processes independently. They rely on a cell, on the host cell, to infect. They infect and they hijack the machinery to reproduce and transmit. And the replication process is not error-free. Many mistakes or mutations can occur. These create a slightly different version of a virus, known as viral strains. Again, these mutations are natural occurrences in the replication process of viruses and they can change the ability of a virus to infect, transmit and even evade the immune system. So immune escape variants or escape mutants are these viral variants that have undergone mutations that allowed them to evade the host's immune system, and they can pause a huge challenge for vaccines and treatments, as they can escape the attacks of our robust immune system and are not neutralized by the immune system.

0:25:31 - Kimberly King

And then, why do we need to stay up to date on our vaccinations?

0:25:36 - Doctor Huda Makhluf

Yes, it's very important to stay up to date. So following the CDC's recommended immunization schedule is best to ensure that the vaccination effectiveness and every community's well-being is preserved. So, more importantly, vaccination is the ultimate disease-preventative plan, especially vaccinating children according to schedule protects children from at least 14 potentially serious illnesses. And here are six reasons to follow a specific schedule. Reason number one is the ideal timing. The schedule is based on how our immune system works at different ages and the vulnerability of a patient to a specific disease at a specific age.

Reason number two - you want to prevent complications from diseases at specific times in one's life. Pertussis or whooping cough, for example, can make an adult cough for three months but can be fatal in a baby, making the vaccine against pertussis critical early on. Reason number three - early protection before exposure to an illness. Getting the flu vaccine in early fall is critical to avoid coming down with flu in winter. Best protection is reason number four. The D-TAP vaccine provides the best protection only after its primary series have been completely administered, the first and all the boosters. Another reason - long-term protection. So maternal antibodies through the placenta and breastfeeding can only protect the baby in the first few months of life. But then you want the baby's own immune system to kick in and start producing its own antibodies and T cell immunity. Reason number six - limit the spread of illnesses in daycares and preschools.

0:27:40 - Kimberly King

That's yeah, that's a good point and that's hard to do when kids kind of put things in their mouths and all of that. But you know we also have our seasons, that we should always. You know, you can always tell when you go to the grocery store. It must be cold and flu season, right, and we're just with the weather change and the time change. Even so, can viruses cause autoimmune diseases?

0:28:05 - Doctor Huda Makhluf

Yes, that's a great question, Kim and they can trigger autoimmunity, especially in genetically susceptible individuals. Viral induced cases of Guillain-Barre syndrome and multiple sclerosis have been well documented. Autoimmunity is a breakdown of self-tolerance. So remember when we said you have to recognize self from non-self. So the autoimmunity auto means self. And then you mount an immune reaction against your own tissue and proteins. So we call this an aberrant immune response that fails to recognize the self antigens as self and it actually mounts an immune response against self-tissues.

Now, multiple mechanisms were proposed to explain this breakdown of self-tolerance by viral infections, such as molecular mimicry, by standard activation and epitope spreading all complex topics beyond the scope of this podcast. But briefly, some viruses carry molecules or antigens that are structurally similar to our own self antigens, which leads to the activation of cross-reactive B cells and T cells against both viral and non-viral or self-antigen. So basically, the immune system is confused it sees the same structure and thinks it's attacking a non-self protein, when in fact the structural mimicry is causing an attack against self proteins. Another proposed mechanism is the bystander activation, where an overreactive antiviral immune response results in inflammation and the release of self proteins from damaged cells, which are taken up and presented by antigen presenting cells, stimulating previously non-responsive yet auto-reactive T cells in the vicinity and thus triggering autoimmunity, something like collateral damage. This mechanism is also similar to epitope spreading, and the viral infection triggers the release of more self antigens and the spreading of autoimmune attacks targeting additional self antigens.

Actually, a recently published study at Stanford University identified how Epstein-Barr virus or EBV, a virus that causes mono or mononucleosis or kissing disease, triggers multiple sclerosis. Their study found that part of the Epstein-Barr virus named ABNA1, Epstein-Barr virus, nuclear antigen 1, mimics a protein made in the brain, in the spinal cord, called the glial cell adhesion molecule or glial CAM. This leads the immune system to attack myelin, a protective coating around our nerve cells. This disrupts the electric impulses between the nerves and causes numbness, muscle weakness, and paralysis. So this discovery of ABNA1 glial CAM cross-reactivity provides undeniable evidence that EBV is a trigger of multiple sclerosis.

Zika virus and Dengue virus also can do that. They both belong to the Flaviviridae family and they have been associated with autoimmune diseases. Specifically, Zika virus can cause Guillain-Barre syndrome in genetically susceptible individual. GBS is a form of paralysis, again, where the immune system attacks our nerves and damages the myelin sheath or protective layer. The influenza virus can cause also GBS and, according to the CDC website, in 1976 there was a national campaign, I believe, for people to get the flu vaccine against a pandemic strain of a swine flu, and those who received the 1976 swine flu vaccine had a slightly increased risk of developing GBS. Future studies conducted on that risk of GBS following flu vaccination suggested that it's more likely that a person will get GBS after getting the flu virus than after a vaccination.

0:32:41 - Kimberly King

Wow, very interesting information, and right now we need to take a quick break, but we'll have more with you in just a moment. Don't go away, we'll be right back. And now back to our interview with National University. Dr. Huda Makhluf and we're talking about what vaccines are and how they work, and it's just fascinating information, Dr. Huda. Why do we have to take the flu shot every year?

0:33:10 - Doctor Huda Makhluf

Well, first, there are four different types of influenza virus - A, type B, type C and type D. Moreover, Kim, the influenza virus consists of eight separate RNA segments enclosed in an inner layer of protein and an outer layer of a lipid envelope lipid layer or envelope. The protruding from the envelope are two types of projections Hema-agglutinin, known as HA spikes, and neuraminidase, NA spikes. Flu viral strains are identified by a variation in the HA and NA antigens. The different forms of the antigens are assigned numbers H1, h2, h3, n1, and N2. For example, H1N1 influenza virus.

So RNA viruses are notorious for their high mutation rates, as they lack a proofreading ability to correct mutations or mistakes in their genetic material that DNA viruses have. So accumulations of these mutations, or what scientists like to call antigenic drift, change the molecular structure of the antigen and allow the virus to evade much of the host immunity. Since these outer structures are constantly changing, a new vaccine is needed each year to target the new structures of the flu viruses and educate the immune system about the currently circulating strains. So each new strain of circulating virus must be identified in time, usually in February, for the development, usually in spring, and distribution of a new vaccine for the next flu season.

0:35:02 - Kimberly King

Wow. So this is a big question and I'm sure it can be controversial, but you know what I'm asking it. Are vaccines safe? And I know you kind of gone through a little bit of the gamut, but I would love to hear your thoughts on that.

0:35:20 - Doctor Huda Makhluf

Great question, Kim. First, do no harm. Attributed to Hippocrates is a code of professional conduct followed by scientists, researchers and clinicians alike. They all have an ethical obligation to the health and well-being of people everywhere. Like any medicine, though, vaccines can cause side effects. Vaccines are rigorously tested for safety to ensure that the benefits of approved vaccines outweigh their risks and to determine which groups of folks should not receive certain vaccines. Now the development of vaccines involves extensive research and clinical trials to assess their safety. The FDA must review all data clinical trial data, preclinical research studies before granting any vaccine approvals. Most recently, some stated that researchers rushed the development of the COVID-19 vaccine so its effectiveness and safety were not to be trusted. Studies have since found that the vaccine was about 95% effective, with no life-threatening side effects. Health officials are always checking information from many sources for evidence that a particular vaccine may cause an adverse health event, but in fact, we all can play a role in monitoring the safety of vaccines by submitting a report to a VAX, a vaccine adverse effect reporting system, or VAERS, that's managed by the CDC and the FDA.

0:36:58 - Kimberly King

So what side effects do vaccines cause?

0:37:02 - Doctor Huda Makhluf

Well, serious side effects that could cause long-term health problems are extremely rare following any vaccine. Again, the most common side effect is local soreness and redness at the site of administration. This resolves in a few days with some supportive measures - cold compresses and anti-inflammatories. Sometimes immunized people feel tired, while others experience appetite loss and fever. Much less often are serious reactions such as seizures, constant crying for three days, and fevers over 105, maybe one in half a million. Most recently, people have worried about cases of myocarditis and pericarditis occurring within seven days after receiving the second dose of mRNA COVID-19 vaccine. These cases have happened most frequently in adolescent and young adult males, at a rate of 146 cases per 100,000. So the clinical course have been generally mild, fortunately.

Some people worry about the use of aluminum as an adjuvant in vaccines and how slowly the body clears it. Aluminum salts have been used safely in vaccines since the 1930s and combination vaccines are one way to minimize the body's exposure to aluminum. Moreover, all vaccines been being given to children under three years old are FDA approved, preservative-free, containing no mercury. Now, in 1998, a publication in England suggested that the MMR vaccine may predispose children to autism. This study received widespread publicity and MMR vaccination rates began to drop. Subsequent studies refuted this speculation, but the damage was done. Today, population vaccination coverage in the UK is 70%. Measles continues to cause frequent outbreaks there because of diminished herd immunity.

0:39:16 - Kimberly King

So you're talking about the different types of those vaccines. Can you answer? Do mRNA vaccines? Do they work?

0:39:26 - Doctor Huda Makhluf

Yeah, how do mRNA vaccines work is a terrific question, Kim. Thank you. Everyone, it seems, has been talking about mRNA vaccines since the pandemic. Are they safe? Will the vaccine RNA get incorporated into our own genetic code forever? In actuality, it was only decades of NIH-supported lab research that led to the success and rapid development of the COVID-19 vaccines in the first few months of a pandemic. What a remarkable story. mRNA vaccines work by introducing a piece of mRNA part of the virus's genetic code that corresponds to a viral protein, usually a small component of a protein located on the virus's outer cover. In the case of SARS-CoV-2, it is the spike protein. In a regular vaccine, one gets injected with the protein particle itself, which stimulates our immune system. This is true with tetanus shots, for example. In mRNA vaccines, the injected component is messenger RNA or mRNA, which then uses our own cell's machinery to produce a protein the spike protein in COVID-19's case which then stimulates the immune system. mRNA does not enter our nucleus, where our DNA is housed and stored. It's very degradable, fragile and duly disposed of.

0:40:59 - Kimberly King

Okay. Well, thank you for explaining that. What are some key advantages of the mRNA vaccines?

0:41:05 - Doctor Huda Makhluf

The biggest advantage Kim, of mRNA vaccines is just how quickly they can be designed, tested and mass produced. They are also fast, relatively inexpensive, scalable and capable of uniform production. The half-life of the vaccine can be regulated by modifying the RNA sequence, so it becomes a plug-and-play type of platform. Individuals who get an mRNA vaccine are not exposed to the virus. Vaccines cannot get infected with the virus by receiving the vaccine. And the effectiveness is also good. In the case of COVID-19, for example, the latest monovialant mRNA vaccination has been determined to be 76 percent effective in preventing COVID-19-associated complications and has remained 56 percent one to two years later.

0:42:08 - Kimberly King

Okay, okay. What are antiviral drugs and how are they different than antibiotics?

0:42:16 - Doctor Huda Makhluf

Okay, great question. Antiviral medications help the body fight off viruses, right? Antiviral against the virus, just like antibiotics, are used to treat bacterial infections. They can ease symptoms and they can decrease the duration of a viral infection. They also lower the risk of spreading illness and lessen the risk of reactivation. Their methods are basically helping the immune system stop the virus from multiplying and lowering the load of the virus, and some examples of antiviral medication include the following Acyclovir, for example, can treat herpes infections, including shingles, genital herpes, and chickenpox. It's most effective when started in the first two days of an infection. This makes the recognition of symptoms crucial.

Tami flu can be used to prevent, both prevent and treat flu types A and type B. Its use is controversial, however, with some specialists questioning the benefit risk ratio of reducing symptoms by just one to two days. Remdesivir to treat COVID-19 was first granted in October 2020 for critically ill patients on oxygen. It has since been fully approved for adults and children down to 28 days of life and be either hospitalized or at high risk for severe disease and illness. And Paxlovid is indicated for the treatment of mild to moderate COVID-19 in adults who are at risk for progression to severe disease. Antibiotics target structures in bacterial cells, for example by damaging their cell wall or blocking protein synthesis, and this is best left for another podcast.

0:44:21 - Kimberly King

(Laughter.) I can imagine. This is these are things that are happening here in the now and then really giving us that history. So, yep, we could probably start a whole other podcast. So, thank you, your knowledge has been just wonderful and we appreciate you sharing that, and if you want more information, you can visit National University's website at nu.edu. And thank you very much for your time today, Doctor.

0:44:47 - Doctor Huda Makhluf

Thank you for having me, Kim.