With vaccine approvals underway, Medical News Today spoke with medical experts about how coronavirus vaccines were rapidly made without compromising safety.

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Last week, the Food and Drug Administration (FDA) granted emergency use authorization for a COVID-19 vaccine created by Pfizer-BioNTech. The United States is the latest country to join Canada and the United Kingdom in approving a COVID-19 vaccine.

Creating a vaccine in under 1 year is no small feat. While the coronavirus pandemic made a new normal of mask-wearing and physical distancing, it also spurred global cooperation for vaccine research and distribution.

However, a vaccine is only effective if people are willing to receive it. With rapid research development, some may be concerned that the vaccine was rushed, and with these concerns comes vaccine hesitancy.

An October study in Nature Medicine surveyed 19 countries and found that only 71.5% of the respondents would consider taking a COVID-19 vaccine and that only 61.4% would take it if their employer recommended it.

Considering that the fastest vaccine — the mumps vaccine — took 4 years to develop, it is natural to have some apprehension over the safety and effectiveness of a vaccine.

Dr. Sam Sun is the director of inDemic Foundation, a nonprofit organization that provides information about COVID-19, and a chief resident at Baylor College of Medicine in Houston, TX.

He told MNT that transparency throughout the vaccine process will be key to debunking misinformation and building the public’s trust.

In this feature, learn how researchers created a COVID-19 vaccine in a short amount of time without compromising safety.

Stay informed with live updates on the current COVID-19 outbreak and visit our coronavirus hub for more advice on prevention and treatment.

Researchers were not starting from scratch when they learned about SARS-CoV-2, the virus that causes COVID-19.

SARS-CoV-2 is a member of the coronavirus family. According to the National Institute of Allergy and Infectious Diseases, there are hundreds of coronaviruses — including four that can cause the common cold, as well as the coronaviruses that sparked the SARS, or severe acute respiratory syndrome, epidemic in 2002 and the emergence of MERS, or Middle East respiratory syndrome, in 2012.

Dr. Eric J. Yager, an associate professor of microbiology at Albany College of Pharmacy and Health Sciences in Albany, NY, told MNT that scientists have been studying coronaviruses for over 50 years. This meant scientists had existing data on the structure, genome, and life cycle of this type of virus.

Dr. Yager explained, “Research on these viruses established the importance of the viral spike (S) protein in viral attachment, fusion, and entry, and identified the S proteins as a target for the development of antibody therapies and vaccines.” He continued:

“Early efforts by scientists at Oxford University to create an adenovirus-based vaccine against MERS provided the necessary experimental experience and groundwork to develop an adenovirus vaccine for COVID-19.”

Under normal circumstances, making a vaccine can take up to 10–15 years. This is because of the complexity of vaccine development.

Dr. Michael Parry, the chair of Infectious Diseases at Stamford Health in Stamford, CT, told MNT that vaccines train our immune system to remember an infectious agent — without our having to contract it.

“Traditionally, they have contained weakened or inactivated parts of a particular virus (antigen) to trigger an immune response within the body. These vaccines will prompt the immune system to respond, much as it would have on its first reaction to the actual pathogen.”

However, amid a global pandemic, time was a luxury the world could not afford. Researchers quickly mobilized to share their coronavirus data with other scientists.

Dr. Yager said that thanks to advances in genomic sequencing, researchers successfully uncovered the viral sequence of SARS-CoV-2 in January 2020 — roughly 10 days after the first reported pneumonia cases in Wuhan, China. The ability to fast-track research and clinical trials was a direct result of this worldwide cooperation.

Vaccine research is costly. In 2018, a study in The Lancet Global Health estimated the cost of early development and initial clinical safety trials for a typical vaccine to be in the range of 31–$68 million. Large scale trials to determine the efficacy of a vaccine candidate would add to these figures.

In an accelerated timetable with a new coronavirus, this cost might be higher. For this reason, funding ranging from the government to the private sector is critical in making COVID-19 vaccines.

In the U.S., Operation Warp Speed (OWS) partnered with multiple institutions, including the National Institutes of Health (NIH) and the Centers for Disease Control and Prevention (CDC), to develop, manufacture, and distribute 300 million doses by early next year.

“By providing resources and assuming the financial risk, OWS allows companies to produce and stockpile vaccine doses even before the company knows if the vaccine is going to work,” said Dr. Yager.

“Also, by investing in multiple companies and vaccine platforms at once, OWS increased the odds of having a vaccine, or vaccines, available by the beginning of 2021,” he added.

The European Commission have also funded several vaccine candidates and worked with others in pledging $8 billion for COVID-19 research.

The UK government Vaccine Taskforce have also been a significant contributor to a wide variety of vaccine research. Recipients of this funding helped develop the Oxford/AstraZeneca vaccine. The designers of this vaccine were the first to publish peer reviewed efficacy results from phase 3 trials.

Several countries have started administering the Pfizer/BioNTech COVID-19 vaccine. It is the first mRNA vaccine to be used in humans outside of clinical trials.

The other company working on an mRNA COVID-19 vaccine is Moderna, who are collaborating with the NIH. In addition to their accelerated development of vaccines, both companies are pioneers in mRNA technology.

Dr. Thomas Kenyon, chief health officer at Project HOPE and former director of the CDC Center for Global Health, told MNT that mRNA technology is something the NIH have been working on for some time.

Dr. Kenyon explained that mRNA vaccines deliver the coronavirus S protein’s genetic material. Our own cells then use the information stored in the mRNA to make the S proteins. The immune system is then “trained” to recognize these spikes, preparing it for a future attack.

“When challenged with the real virus, your immune system attacks the real surface protein of the virus and inactivates it through the immune system capabilities,” Dr. Kenyon told MNT.

According to Dr. Kenyon, misinformation surrounding mRNA vaccines stems from a concern that the vaccine infects people with the virus.

“Nobody is getting infected with a COVID vaccine. It is only the surface protein that would be replicated because we have given you the messenger RNA. It is not the entire virus,” he explained.

One misconception is that an mRNA vaccine would not be useful if the virus mutates.

A July study published in Frontiers in Microbiologyconfirms that the virus mutates. After analyzing 48,635 samples of SARS-CoV-2, the researchers identified an average of 7.23 mutations per sample.

A more recent study, published in November in Nature Communications, found that a D614G mutation in the S protein made it more infectious. However, there was no evidence to suggest a link between the mutation and more severe illness.

While mutations are possible, Dr. Sun said it should not be a cause for alarm.

“There has been an estimated 250,000 variants or strains of SARS-CoV-2 sequenced in the lab. For the most part, the virus has a low mutation rate compared to the mutation rate of the influenza virus,” Dr. Sun explained. “The spike protein is important for the ability of the virus to infect humans’ cells. I think it would not mutate enough for the vaccines to be ineffective.”

In addition, according to Dr. Parry, virologists are continually monitoring and examining for any significant changes from new strains of the virus.

Another concern is whether natural immunity would be more effective than a vaccine. The CDC say that there is insufficient evidence to determine how long a person builds up immunity after recovering from COVID-19.

There are also false claims regarding herd immunity. The World Health Organization (WHO) explain that herd immunity can lower the spread of the virus after a certain number of people have been vaccinated.

For this reason, there is currently no evidence of herd immunity through natural immunity. WHO advise that intentionally exposing oneself to the virus can lead to more infections and an increased risk of death.

“Natural immunity is not better than vaccine-acquired immunity. These vaccines have the potential to provide you with protective immunity without the risks associated with infection,” Dr. Yager told MNT.

In the U.S., the FDA meticulously review the data from each clinical trial phase before approval or, in the case of public health emergencies, before granting emergency use authorization.

Dr. Kenyon said that before any clinical trial can start, a data monitoring and safety board must approve a study protocol.

A phase 1 trial focuses on the safety of the vaccine candidate. Escalating doses of the vaccine are given to healthy volunteers to determine side effects and tolerability.

Phase 2 trials expand their recruitment and may include participants with health conditions such as obesity, cancer, and diabetes. There is also active recruitment for participants of various demographics. The trial continues to test the safety of the vaccine and looks at the drug’s initial efficacy and how it affects the immune system.

Phase 3 trials recruit thousands of participants to measure the efficacy of the vaccine in preventing disease.

Clinical trials may combine their phases, which according to Dr. Yager is a common practice that is still held to the same ethical, scientific, and statistical standards as when each phase is done separately. He explained:

“One potential benefit of combined trials, particularly in phase 2/3, is that since the vaccine is being evaluated in subgroups of individuals, results from the study expedite the identification of patient factors that impact vaccine safety or efficacy.”

Dr. Yager said that a major factor behind the rapid completion of clinical trials was a high interest in volunteers for vaccine studies. This helped enrollment goals for reaching thousands of people relatively quickly.

Another factor was the increased number of testing sites to facilitate enrollment and to collect large amounts of data.

Even after emergency use authorization has been granted, Dr. Kenyon said safety data will continue to be collected, as participants are followed for up to 2 years. This adds another layer of reassurance as a person shifts from a trial to a real-life setting.

“The trial is tens of thousands of participants, but for the vaccine program, you are getting into the millions. While unlikely, it may uncover any undetected toxicities that were not picked up by the trial.”

The CDC will monitor safety after vaccination for acute care and long-term care facilities through the National Healthcare Safety Network. For the general population, there is a smartphone application called V-safe.

“It is a smartphone-based system where you will be contacted actively by CDC to see how you are doing after being vaccinated and therefore pick up any adverse events that were not picked up in the trials,” Dr. Kenyon explained.

The pandemic has ushered in a new era of vaccine research. A global collaboration of scientists and the development of mRNA vaccines is akin to the “landing on the moon moment,” according to Dr. Yager.

As COVID-19 cases continue to surge in many areas of the world, the challenge for widespread vaccine rollout will lie in its uptake by the public.

For live updates on the latest developments regarding the novel coronavirus and COVID-19, click here.