Highlights
- A dynamite vaccine, one that knocks out SARS-CoV-2, would be the most ideal scenario.
- But there are many unknowns, with a number of scenarios seen post Phase-III trials
- What if the best vaccine is only 50% effective? Or one shot is only marginally effective, but heavily promoted?
- What if there are multiple successes, in multiple places?
- Here, we outline the five most likely scenarios
DUBAI: A dynamite vaccine is one that works with a single dose, or maybe just two.
Example: measles vaccine.
Extensive trials on different COVID-19 vaccine projects have kicked up great expectations. Are we going to get 100% safe — and 100% effective — shot?
At the moment, no one on earth can guarantee a godsend like that.
With infections around the world still spiking, it increasingly looks like only a vaccine could stop this virus on its tracks, and bring the world back on its feet.
A vaccine trial is like a well-choreographed dance, or a chorale presentation. One wrong move, or an out-of-tune note — and it bombs.
A really good inculation shot, however, is also likened to a "dynamite vaccine". It works with just one or two jabs, and protects for life.
In human trials, thousands of people are already getting — or about to get — shots in the arm in Asia, Europe, the Americas, Africa, Australia. And unlike any “race”, there are no umpires here. Only rules.
Finish line
Experts are clear on this one point: Vaccine development is not about who gets initial approval. Authorities and drug regulators may not always settle for whoever is the first to get past Phase III trials.
For public health officials, deciding when a vaccine is ready to be used – on healthy population – is a delicate balancing act.
What if, instead of a dynamite vaccine, the best one offers only limited protection from the virus?
What if, instead of a dynamite vaccine, the best one offers only limited protection from the virus?
Experts have outlined a number of scenarios out of the 17 leading Phase III clinical trials, and the 130-odd others that may follow:
Scenario 1: No COVID-19 vaccine
The HIV epidemic has been with us for almost 100 years. The HIV1 – subgroup M – was first discovered in Léopoldville in the Belgian Congo (now Kinshasa, DR Congo) in the 1920s. The first documented sample of HIV was found in 1959 in Congo.
Since the beginning of the HIV epidemic, 75 million people have been infected with the HIV virus and about 32 million people have died.
However, scientists are working to develop one. Research efforts include two late-stage, multinational vaccine clinical trials called Imbokodo and Mosaico.
A no-vax scene for COVID-19 is highly unlikely, given the numerous ongoing trials that show "promise" and the massive global effort to fight the coronavirus menace. But it's one possibility, given the HIV vaccine experience.
This isn’t a race of who gets there first. This is: get as many approved, safe and effective vaccines as you possibly can.
Scenario 2: Limited efficacy, but promoted heavily
A COVID-19 vaccine with low efficacy (or limited effectiveness) is approved, but is mass produced and promoted heavily.
If you think of recent events, the way hydroxychloroquine was touted much based on fuzzy data, with subsequent trials showing it failed to reduce deaths, you'd get a better picture of this scenario.
In the time of fake news and social media, experts warn against this over-touring unproven jabs. For example, Roland Sutter, WHO coordinator for research, policy, product development, and containment for polio until retiring in December cautions against this. The reason: This may discourage other developers from working to bring out a better one.
“If you accept a vaccine with low efficacy, then you probably prevent the development of a vaccine with higher efficacy,” he told the National Geographic.
Scenario 3: Effective, but with some adverse side effects
A vaccine generates effective immune response, but may also cause some adverse side effects. In the coming months, scientists and health policy makers must resolve the question: “What makes a COVID-19 effective and safe for mass immunisation?”
They will also need to ensure appropriate safety checks are done. As with any new vaccine, there are risks involved. No one wants a repeat of past mistakes with vaccines and losing public confidence. Age-stratified trials are also of tmost importance.
"As you get into older adults (given a new vaccine), of course those people come along with chronic underlying illnesses. They may not respond (to the new vaccine) optimally," Dr William Schaffner of the Vanderbilt University Medical Centre, told Contagion Infectious Diseases Today.
"We have to assess not only adults, but also children. And you have to look at immunocompromised people, older people who usually don't respond as well. So there're all kinds of subgroups where you have to look at effectiveness."
Scenario 4: The best COVID-19 vaccine is only 50% effective
If the best COVID-19 vaccine is only 50% effective, "that's still, to me, a great vaccine," said Dr. Drew Weissman of the University of Pennsylvania.
Dr Schaffner cited the influenza vaccine which, for a variety of reasons is "only 45% to 50% effective" (effectiveness depends upon the population to whom you give it).
“That is the best that science can produce now. We wouldn't want a vaccine only that effective…we will deal with it if it’s the only vaccine available, I think.”
Scenario 5: 100% effective, 100% safe, but very expensive
A vaccine that's 100% effective and is also 100% safe would be fabulous. At the very least, this would prove the effectiveness of the technology or platform used in its development.
But if each vial costs a fortune, the way Gilead has priced Remdesivir at $2,340 (Dh8594, or Rs174,750) for a five-day course, that would be a real bummer: COVID-19 could be a death sentence for the poor, infirm.
To hope this profits-over-health equation won't happen, could be shooting for the moon. The are moves towards making access to an effective and safe vaccine equitable.
Presumably, economies of scale (in production) would eventually help bring down per-unit price of the vaccine, the way polio vaccines have gone down to about $0.50 per vial today.
IDEAL SCENARIO: Multiple successes, multiple parts of the world
This is the dynamite outcome. And It's quite possible, given the "warp-speed" trials in the in US, at least five candidates in advanced human trials in China and several in India, a country able to mass produce jabs by the hundreds of millions for the world. Europeans and Thais are at it, too.
“This isn’t a race of who gets there first. This is: get as many approved, safe and effective vaccines as you possibly can,” said Dr Anthony Fauci, director of the US National Institute of Allergy and Infectious Diseases (NIAID).
Multiple trial successes, in multiple parts of the world, would allow humanity to put this malaise behind us.
“I think today,” says Dr Schaffner, “in the 21st Century, we have to have a product that is at least 80% effective. They (scientists) would even hope for more, of course."
It’s got an adjuvant in it, an immune stimulant. When the vaccine results came out, people almost cheered. And that's why it's been such great demand. So if you had a vaccine that were that good, that would be fabulous.
“Every once a while … you can get a (good) vaccine. The most recent shingles vaccine, Shingrix, is an incredibly effective vaccine, even in people who are older,” according to Dr. Schaffner.
“It’s got an adjuvant in it, an immune stimulant. When the vaccine results came out, people almost cheered. And that's why it's been such great demand. So if you had a vaccine that were that good, that would be fabulous,” Dr Schaffner said.
Within the dynamite vaccine and no-vaccine continuum, there are numerous possibilities.
Whatever scenario pans out post Phase-III trials will reshape our lives, hopefully for the better.
In other words, adjuvants help vaccines work better. Some vaccines that are made from weakened or killed germs contain naturally-occurring adjuvants and help the body produce a strong protective immune response.
However, most vaccines developed today include just small components of germs, such as their proteins, rather than the entire virus or bacteria.
Adjuvants help the body to produce an immune response strong enough to protect the person from the disease he or she is being vaccinated against. Adjuvanted vaccines can cause more local reactions (such as redness, swelling, and pain at the injection site) and more systemic reactions (such as fever, chills and body aches) than non-adjuvanted vaccines.
ARE ADJUVANTS SAFE?
Adjuvants have been used safely in vaccines for decades. Aluminum salts, such as aluminum hydroxide, aluminum phosphate, and aluminum potassium sulfate have been used safely in vaccines for more than 70 years. Aluminum salts were initially used in the 1930s, 1940s, and 1950s with diphtheria and tetanus vaccines after it was found they strengthened the body’s immune response to these vaccines.
Newer adjuvants have been developed to target specific components of the body’s immune response, so that protection against disease is stronger and lasts longer.
In all cases, vaccines containing adjuvants are tested for safety and effectiveness in clinical trials before they are licensed for use in the United States, and they are continuously monitored by CDC and FDA once they are approved.
