COVID-19 Vaccine development could shape the future of immunization

Three pharmaceutical manufacturers have announced that they have a vaccine for the novel COVID-19 virus (SARS-CoV-2) with at least 90% effectiveness against the disease in late-stage trials.

Last week, American corporations Pfizer and Moderna Therapeutics announced vaccines that were nearly 95% effective in late-stage trials, according to preliminary results. Both corporations pursued inoculations for SARS-CoV-2 through the Messenger RNA (mRNA) method, a type of vaccine development that seeks to amplify antibody resistance to pathogens through antigen sequencing.

The method of vaccine development, first introduced as a concept in 1961, has been dubbed “revolutionary” by epidemiologists and has only been in serious development since the early 2010s when Moderna was formed. The COVID-19 pandemic pushed mRNA vaccine development into overdrive this year, fueled by government and private funding from across the globe.

Pfizer applied for an emergency use authorization on Friday from the Food and Drug Administration for its mRNA vaccine candidate; the FDA's decision is expected on Dec. 10.. According to the top science adviser for Operation Warp Speed, Dr. Moncef Slaoui, that means that Americans could receive vaccinations against COVID-19 as soon as Dec. 11.

“Our plan is to be able to ship vaccines to the immunization sites within 24 hours from the approval, so I would expect maybe on Day Two after approval, on the 11th or on the 12th of December, hopefully, the first people will be immunized across the United States, across all states, in all the areas where the State Departments of Health will have told us where to deliver the vaccine,” Slaoui told CNN on Sunday.

The vaccine candidate from Pfizer, however, requires ultra-cold storage temperatures that could mean slower distribution, particularly in developing regions. Moderna’s candidate can be stored temporarily at normal refrigerator temperatures, but only for 30 days. But on Monday, a third corporation, British-Swedish drug company AstraZeneca, announced that late-stage trials yielded a 90% effectiveness rate for their vaccine that does not require the same stringent storage requirements as the first two products.

AstraZeneca's results were based on an interim analysis of the vaccine candidate conducted in the United Kingdom and Brazil and achieved 90% efficacy by first administering a half-dose followed by a full-dose; no deaths, hospitalizations, or severe cases of COVID-19 were reported in the trial.

AstraZeneca, which produced the mRNA vaccine developed by Oxford University, also pledged not to profit off any SARS-CoV-2 vaccine during the pandemic should it reach the global marketplace, making their potential vaccine a less-expensive option than the candidates being submitted from Moderna and Pfizer. Each dose of the AstraZeneca Vaccine could cost as little as $2.50 where estimates for the Pfizer and Moderna vaccines are estimated to cost approximately $15-20 per dose.

“I think these are really exciting results,” chief trial investigator for the Oxford-AstraZeneca vaccine, Dr. Andrew Pollard, said. “Because the vaccine can be stored at fridge temperatures, it can be distributed around the world using the normal immunization distribution system. And so, our goal to make sure that we have a vaccine that was accessible everywhere, I think we’ve actually managed to do that.”

Should a vaccine reach the marketplace by December, it will have been less than a year since the first case of COVID-19 was diagnosed in the United States. No vaccine in history has been developed to fight any pathogen at that speed, according to science magazine Nautilus, which said the fastest development of any previous vaccine was four the mumps; that took four years to develop. The rapid development of vaccines against the novel coronavirus can reshape all future and existing vaccines, said Executive Director of The International Vaccine Access Center at The Johns Hopkins Bloomberg School of Public Health, Dr. William Moss. The mRNA technology, Dr. Moss said, is truly groundbreaking.

“I think what the majority of these trials have shown us that this can really work and achieve much higher levels of protection than many people expected,” Dr. Moss told Sinclair. “And that is a type of technology that can be readily adapted for other pathogens. I anticipate that first of all, should there be another pandemic, that's a technology that could easily be adapted for a new pathogen, and perhaps even, taking some diseases or pathogens for which we already have vaccines, and making them better using this technology.”

Unlike the traditional flu vaccine, the mRNA vaccine does not give the recipient a diluted version of the pathogen it is designed to resist. Instead, the vaccine sequence codes for antigens, the disease-fighting agent proteins that resemble those of the pathogen. Once the vaccine is administered, the body translates the sequence and produces encoded antigens, stimulating the immune system to produce pathogen-fighting antigens.

As with any new technology, questions abound about the vaccine’s safety and long-term efficacy. But Dr. Moss says the mRNA vaccines are promising and could provide recipients with long-term immunity.

“The true answer is we don't know how long the duration of immunity or protection will last after these Messenger RNA vaccines but we do know that these vaccines not only induce an antibody response, but also a cellular immune response,” Dr. Moss said. “And it's that cellular immune response that provide what we call the ‘immunologic memory,’ and that's what allows for the long duration of protection.”

“I think it's quite possible that these vaccines will induce a longer-term immunity,” Dr. Moss said. But, he said, until more time passes, and more people are inoculated with the mRNA vaccines, there is no way to be sure of the long-term efficacy. The worst-case scenario, he said, was that the vaccines could require a booster in the future.

Dr. Moss said that the break-neck speed of mRNA vaccine development in 2020, even though the method had been in development for several years, was due largely to public and private funding, concurrent with the phase three trials.. New vaccines don’t normally see that kind of funding until they have completed the third stage of trials, and pharmaceutical companies are assured the vaccine will go forward, he said.

“The time was kind of right for these vaccine technologies to be used against this new pathogen,” Dr. Moss told Sinclair. Another key factor in fast-tracking the trials, he said, was the high-transmission rate of COVID-19 and the number of people infected.

“In the midst of a pandemic with the level of transmission that's going on, we can get the results from the phase three trials – these very large, tens of thousands of individuals trials – that are looking at both safety and efficacy,” he said. “We can get the results of those pretty quickly because a lot of cases occur in trial participants. Normally, that process takes much longer just because it takes more time to accumulate enough cases in the trial participants.”

Dr. Moss said that even though there are still some unknown factors about the mRNA vaccines and both distribution and participation will face challenges, he sees the vaccines as the road back to “pre-pandemic” life for most Americans.

“Seeing these results or these preliminary results, and the press reports from them, and the very high protective efficacy, I think we will get back to a much more normal situation,” Dr. Moss said. But unlike inoculation for children, medical professionals, and nursing home residents, it will be difficult to track the most vulnerable Americans to give them the vaccine. Widespread inoculation that brings the country back to pre-pandemic life may not happen until the second or third quarter of 2021, he said.

The mRNA technology could not only end the COVID-19 pandemic but set the stage for future fights against novel pathogens and other illnesses including cancer, according to the University of Cambridge. And it could do it in record-breaking time.