Will the coronavirus stay with us forever? Yes, most likely. It’ll be more like common cold and influenza. All available evidence points to that.
A safe and effective vaccine could change all that. But it seems like a distant prospect, although some companies have reached the third phase of human trials.
Vaccines are the only way of eliminating COVID-19 from the face of Earth. We did that with smallpox. Immunisation was very effective against polio and measles also. The anti-malaria vaccines work only in 30 per cent people, yet that’s a tremendous gain.
More than 30 years have passed since the HIV, the virus that causes AIDS, first surfaced, but a vaccine has not been found. A vaccine for dengue fever was approved only last year, although the virus was identified in 1943.
If an effective vaccine is developed, much of the population around the world could gain herd immunity. But that’s not easy. A lot depends on how long the immunity would last. So SARS-CoV-2 will become endemic at least for a while.
The tricky business of vaccines
Vaccines are a tricky business. Since mutating pathogens are like moving targets, vaccines have to be continually updated. Take the case of common flu. There are effective vaccines, but every year you should get a flu shot that takes care of the new strains.
Now with COVID-19, the scenario gets even more muddled. We are yet to fully comprehend the full range of complications presented by the new coronavirus. SARS-CoV-2 is a new virus, and more research is required to understand the extent of inter-human transmission and the full spectrum of clinical disease.
But scientists have responded well to the challenge of the new virus. The Chinese were quick to sequence the genome of the coronavirus, which originated in Wuhan. The genetic code was shared in January with the rest of the world so that researchers can get to work on developing cures and vaccines. And that helped start safety trials of vaccines in March.
The challenge of developing vaccines
Vaccines are given to healthy people, that’s billions of people without the disease. They should develop immunity and not fall ill. So the vaccines should be safe, without dangerous side-effects. This is the challenge of vaccines.
Vaccine development typically takes 10-15 years. Each vaccine is different depending on the nature of the disease. So each of them goes through several phases of trials in animals and humans before it is approved for use. The vaccine for mumps was the fastest to be developed, and that took four years.
That gives us a fair idea of the daunting task for vaccine developers.
Since COVID-19 is a highly contagious pandemic, vaccine development has been fast-tracked. Some of the trials on humans have combined Phase I and Phase II to speed up the process. In some countries, some safety regulations have been waived in haste to produce a vaccine.
The sprint for vaccines
In the race to beat back the new coronavirus, governments around the world are pouring money into efforts to develop a vaccine that can be mass-produced. More than 150 pharmaceutical companies and research facilities are working on around 180 potential vaccines. At least 23 of them are now testing their vaccines in humans.
Right now, there’s only one vaccine in use, one that was developed in around six months, which is lightning fast. And the Chinese government gave emergency authorisation use for army personnel.
The vaccine being developed by the University of Oxford is the frontrunner in the race according to Soumya Swaminathan, chief scientist for the World Health Organisation. Backed by AstraZeneca, a British pharmaceutical company, it has reached Phase III trials, the final stage before licensing. In a study published in The Lancet on July 20, the researchers said the vaccine increased levels of neutralising antibodies and immune T-cells that target the virus. If it proves to be safe and effective, full approval could come in early 2021, which would be a remarkable feat.
A vaccine developed by Chinese company Sinopharm has started the final-stage trial. Abu Dhabi-based G42 Healthcare is performing the Phase III trials in cooperation with Sinopharm, under the auspices of the Department of Health and the UAE Ministry of Health.
In May, the US government launched Operation Warp Speed, allocating billions of dollars for the development of potential vaccines. Several vaccines developed by American companies are progressing well, but only Moderna has reached the final trials.
The RNA vaccine gamble
A vaccine developed by computers will be a milestone in modern medicine. The coronavirus pandemic has given scientists an opportunity for a high-stakes gamble to manufacture a vaccine in a totally new way.
The new generation vaccine technology is based on injecting a tiny snip of genetic code called messenger RNA (ribonucleic acid), or mRNA, to elicit an immune response.
RNA vaccine technology has the potential to prevent a wide range of infectious diseases, including influenza and cancer. But is uncharted territory. At present, there’s no RNA vaccine in use. So why pursue an untested route?
The lure is overwhelming. It’s cheap and easy to produce and faster to manufacture on a massive scale. Which is why researchers in Britain, Germany, China and the United States are using computers to design a vaccine using the genetic sequence of SARS-CoV-2.
Moderna is ahead in the race to produce an mRNA vaccine. In the data from Phase I trials, published in the New England Journals of Medicine last week, the US biotechnology company said the vaccine induced immune responses in all the volunteers, but with mild side effects like fatigue, chills, headache and muscle pain. The vaccine is expected to begin the final Phase III trials on July 27.
■ PHASE I: These are safety trials. Three different doses will be tested, each in 15 people. The participants will be studied to determine whether the vaccine is safe and whether it stimulates the immune system to make antibodies that can stop the virus.
■ PHASE II: The second round of testing is expanded to include more participants and will measure efficacy, and verify the safety of the vaccine. It will be given to hundreds of people divided into groups, such as children and the elderly, to see if the vaccine acts differently in them.
■ PHASE III: In these efficacy trials, the vaccine is given to thousands of people to see how many are infected, compared with volunteers who received a placebo. These trials can determine if the vaccine protects against the coronavirus.
■ APPROVAL: It is for each country to decide. Regulators will review the results and decide on approving the vaccine. A vaccine may receive emergency use authorisation, like in China, during a pandemic.
Source: New York Times
How long will immunity last?
Like other coronaviruses, SARS-CoV-2 too is likely to trigger an immune response. But a major concern is the duration of the immunity. Since the virus has been around for only six months, it’s difficult to ascertain the strength of immunity.
Research on SARS 1 and MERS show that some level of antibody immunity will persist for two to three years before waning over time, Robert Samstein, immunologist and radiation oncologist at the Icahn School of Medicine at Mount Sinai, told Live Science.
Researchers are still uncertain about long-term immunity and protection against future COVID-19 infections. Scientists at Rockefeller University in New York found that most patients who were not hospitalised did not possess strong killer antibodies against the new coronavirus.
A study by King’s College London showed that the immunity developed by recovered COVID-19 patients fizzled out in three months, a report in the Guardian said.
“People are producing a reasonable antibody response to the virus, but it’s waning over a short period of time and depending on how high your peak is, that determines how long the antibodies are staying around,” said Dr Katie Doores, lead author of the study.
Why a COVID-19 vaccine may not be effective
The waning immunity found in recovered COVID-19 patients could affect the development of a vaccine, especially if its focus is on developing antibodies. Even if an effective vaccine is designed, its protection may be short-lived. Which means people have to be inoculated every few months with booster doses to prevent seasonal waves of reinfections.
“If the natural infection doesn’t give you that much immunity except when it’s a severe infection, what will a vaccine do? It could be better, but we don’t know,” Stanley Perlman, professor of immunology at the University of Iowa, was quoted as saying.
How vaccines affect herd immunity
If a vaccine cannot offer long-term protection, then there’s no hope for “herd immunity” in a community. Because vaccines provide the best route to herd immunity since the antibodies are developed through inoculation rather than infection.
Herd immunity occurs when a group of people develop sufficient antibodies to become resistant to disease. It happens when a virus infects all the people in a community and makes them immune. The pathogen will no longer find weak hosts, and the outbreak will vanish on its own.
Although the concept has its detractors, vaccines rather than infections are seen as a preferred route to herd immunity.
“It [the King’s College study result] puts another nail in the coffin of the dangerous concept of herd immunity,” Prof Jonathan Heeney, a virologist at the University of Cambridge, told the Guardian.
more on the topic
- Oxford COVID-19 vaccine shows dual immune response
- COVID-19 vaccine could be ready by October, claims Pfizer CEO
- Timeline: Do vaccines really work?
- If a COVID-19 vaccine is approved today, will I get it tomorrow?
- The first coronavirus vaccine tested in humans shows early promise
- 'Killed virus' against COVID-19: How it works
Vaccine hopes are not lost
The uncertainty over an enduring COVID-19 immunity does not diminish the hopes for a vaccine. That will spur researchers to find ways to elicit a highly effective immune response that could last longer. So we are more likely to get a better vaccine.
"You can aim at inducing protection that would be better than what you would get from an infection," Nicolas Vabret, an assistant professor of medicine at the Mount Sinai Icahn School of Medicine who specialises in virology and immunology, told Live Science.
When will the pandemic end?
Immunity is critical for a return to normality. Since the virus is expected to stay around, we would become immune to it, epidemiologists say. Some may fall ill and recover soon. There would be fatalities too. Vaccination offers the only hope of reducing deaths as it would pave the way for herd immunity.
“For this pandemic to end, we need to achieve herd immunity,” Byram Bridle, a viral immunologist at the University of Guelph’s Ontario Veterinary College in Canada, told the National Geographic, adding that a vaccine which is only effective for 50 per cent of the population falls short of getting us to that goal.
An ideal COVID-19 vaccine should be able to establish immunity in at least 70 per cent of the population, including the elderly, the WHO says. Anthony Fauci, director of the US National Institute of Allergy and Infectious Diseases, concurs.
What happens when we get a vaccine?
When an effective vaccine is designed, there will be a scramble since there won’t be enough stock. Affluent countries will use their power and money to secure massive supplies.
For a vaccine to reach the general population, it will take time. Mass production will be the biggest hindrance. Not all pharmaceutical firms can scale up production to deliver enough vaccines to fight a global pandemic. Next comes distribution. The vaccines have to be shipped around the world as almost all countries are battling the virus.
Who gets the priority? According to WHO’s draft plan, the first three high-priority recipients will be healthcare workers, followed by high-risk adults, and then adults over 65 years. That is about one-quarter of the world population. The Science journal estimates that those 1.85 billion people will need about 4.2 billion vaccine doses if you calculate two per person plus 15 per cent wastage.
When will we have a safe vaccine?
Hopefully, next year. Till then let’s wear masks, practise social distancing and wash our hands often to keep out the coronavirus.