2015  |  2016  |  2017  |  2018  |  2019  |  2020

Why does it take so long to make a vaccine? - (3/24/2020)

By Dr. Ron Gasbarro 

Mr. Harrison came into the pharmacy to gather a few things before he self-quarantined himself for two weeks. “Why the heck can’t they find a vaccine for this tiny virus? How hard can it be?” he asked the pharmacist. Nothing can bring the human race to its knees more absolutely than a pandemic. Not a war. Not a storm. Not a zombie apocalypse. Because a viral pandemic can envelop every person on our tiny planet. Our only defense, aside from awkward social distancing, is to create a vaccine to fight back. 

Yet, why does it take so long to develop a substance that can immunize humanity against an invader that is only 0.0000008 inches in diameter? First, we do not know a novel virus exists until people begin to get sick. Often, the primary areas of an outbreak have poor medical infrastructures and no one is isolated. Second, the bugs are clever. Like influenza, they can mutate into various strains. To successfully secure a vaccine means knowing what the strains are. Third, no one is in charge. Although the World Health Organization (WHO) creates a framework by which a new disease can be thwarted, it is not set up to coordinate global research programs. The only hope is that national health organizations will adopt the WHO's agenda and do the work themselves. On the street level, panic and misinformation abound during a pandemic. Anti-vaxxers create fear. Politicians, with their own agendas, create distrust. 

Fourth, small animal models are typically used to initiate trials of a vaccine. However, the models do not always match up with a disease that explicitly attacks humans. When the Zika virus emerged as a global threat in 2015 and 2016, another two months passed before a suitable animal model was discovered. Lastly, trials on humans take a long time. By the time investigators identify and analyze the necessary efficacy and safety data, the disease has passed out of the epidemic stage. Hence, not enough patients exist to get the vaccine approved for commercial use. A full decade can pass before the public can utilize a safe and effective vaccine. 

Our scientists, despite their best efforts, their enduring perseverance, their vast intelligence, have been stumped in the past. Flashback to 1935. Polio was crippling people. At the time, researchers were studying the effect of a polio vaccine on kids, with promising results.. However, the studies were canceled because vaccinated children had died during the studies. Vaccine researchers dared not return to their laboratories for another 20 years when a safe vaccine was finally formulated. 

One vaccine does not fit all people or viruses. According to the US Department of Health and Human Services, live vaccines use a weakened form of the virus that triggers a disease. Examples: Smallpox, chickenpox. Inactivated vaccines use the killed version of a virus. Examples: Influenza, rabies. Conjugate vaccines use particular pieces of the virus, such as its protein or sugar. Examples: Shingles, typhoid. Toxoid vaccines use a toxin made by the virus that has been made harmless but creates an immune response against the toxin. Examples: Diphtheria, tetanus. 

New technologies are also maturing. For example, DNA vaccines are relatively easy and inexpensive to manufacture and they produce strong, long-term immunity. Conceivably, they could control malaria and chlamydia. When we remember that, even though researchers identified human immunodeficiency virus (HIV) 40 years ago, no vaccine has ever evolved against that once fatal virus, antiretroviral medications have saved millions of lives. As the pharmacist said to Mr. Harrison, “Employing drugs may be the only path to stave off the coronavirus while civilization waits for a vaccine that will save us.” 

Ron Gasbarro, PharmD, is a registered pharmacist, medical writer, and principal at Rx-Press.com.


Show All News Headlines